gemini criminology online review and training center p e n e t e e a p · 2016. 5. 26. · icitap...

ICITAP Crime Scene Specialist Course

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GEMINI CRIMINOLOGY ONLINE REVIEW AND TRAINING

CENTER

P E N E T E E A P

Dr. MANUEL V JAUDIAN, LLB. PhD ETEEAP DIRECTOR

NOTES COMPILED AND EDITED BY: PROF. HERMOGENES MALAGAMBA

FORENSIC PHOTOGRAPHY

FORENSIC PHOTOGRAPHY- is defined as the study of the fundamentals of

photography, its application to police work and the preparation of photographic evidence.

It consists of the legal aspects of photography that covers the following phases:

a) Fundamental concepts of photography

b) Application to police work

c) Preparation of photographic evidence

According to (Redsicker 2001), Forensic Photography is the art or science of

documenting

photographically a crime scene and evidence for laboratory examination and analysis for

purposes of court trial.

Photography- is from Greek words “Phos” or Photo which means light and “grapho”

which means to “Draw” or graphia meaning “write”. Therefore photography best

translates to “write with light”. (Herschel 1839). This word is defined as an art or

science that deals with the reproduction of images through the action of light upon

sensitized material (film and photographic paper) with the aid of the camera and its

accessories and the chemical process involved therein. (Modern definition)

Modern photography may be defined as any means for the chemical, thermal,

electrical or electronic recording of the images of scenes, or objects formed by some type

of radiant energy, including gamma rays, X-rays, ultra-violet rays, visible light and

infrared rays.(Technical/Legal definition) This definition is broad enough to include not

only the conventional methods of photography but almost any new process that may be

developed. (Scott 1975)

Police Photography- is an art or science that deals with the study of the principles of

photography, the preparation of photographic evidence and its application to police work.

(Aquino 1972).

PHOTOGRAPHY IN CRIMINAL INVESTIGATION: Photography is an essential tool for the law-enforcement investigator. As a tool, it enables him to record the visible and in any cases, the invisible evidence


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of crime. Special techniques employing infra-red, ultra-violet, and x-ray radiation enable him to record evidence which is not visible. The photographic evidence can then restored indefinitely and retrieve when needed. There is not other process which can be ferret, record, remember, and recall criminal evidence as well as photography. Photographs are also means of communication. It is a language sometimes defined as the “the most universal of all. Photography has an advantage as languages because it does not rely upon abstract symbols-words. Photography, thus, is more direct and less subject to misunderstanding. As a communication medium-has few, if any, equal. FUNCTIONS OF PHOTOGRAPHY IN INVESTIGATE WORK

1. Identification A. Criminal B. Missing person C. Lost and stolen properties D. Civilian

2. Communication and microfilm files A. Transmission of photos (wire or photos) B. Investigative report file 3. Evidence A.) Recording and preserving

1. Crime scene 2. Vehicular accidence 3. Homicide or Murder 4. Robbery cases 5. Fires or Arson 6. Object of evidence 7. Evidential traces

B.) Discovering and proving 1. By contrast control (lightning, film and paper, filter) 2. By magnification (photo micrography, photo macrography) 3. By invisible radiation(infra-red, ultra-violet, X-ray) 4. Action of offenders (recording)

4. Action of offenders (recording)

a) Surveillance b) Burglary


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c) Confessions d) Reenactment of crime

5. Court Exhibits

a) Demonstration enlargements b) Individual photos c) Projection slides d) Motion pictures

6. Crime prevention

a) Security clearance 7. Public relations 8. Police training

a) Prepared training films (police tactics, investigation techniques) b) Traffic studies

c) Documentaries (Riots and mob control, disasters, prison disorders) 9. Reproduction and copying a) Photographs b) Official records

PRINCIPLES OF PHOTOGRAPHY A photograph is both the mechanical and chemical result of photography. To produce a photograph, light is needed aside from sensitized materials (film or papers). Light radiated or reflected by the subject must reach the film while all other lights are excluded. The exclusion of all other lights is achieved by placing the film inside a light tight box (camera). The effect of light on the film is not visible in the formation of images of objects. To make it visible, we need or require a chemical processing of the expose film called development. The visual effect of light on the film after development varies when the quantity quality of light the reached the emulsion of the film. To grant in greater amount of light will produce an opaque or very black shade after development. Too little produces a transparent or white shade after a development. The amount of light reaching the film is dependent upon several factors like lighting condition, lens opening, shutter speed, & filter used. HISTORY OF PHOTOGRAPHY


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Equipment -1700 – Camera Obscura (dark chamber) was designed by Leonardo da Vinci for accurate perspective and scale. Chemicals-1725 – 1777 – Light sensitivity of silver nitrate and silver chloride solution had been discovered and investigated. 1800 – Thomas Wedgewood and Humphery Davy – produced photograms. True Photography accomplished by:

1. Joseph Nicephore Niepce-1816 – was able to obtain camera images on papers sensitized with silver chloride solution.

2. Louis Jacques Daguerre-1839 – “Daguerreotype”- The first practical photography process. Image was made permanent by the use of hypo.

3. William Henry Fox Talbot-1841 – he patented “Calotype” process negatives on paper sensitized with silver-iodide and silver nitrate. These were contact on sensitized paper. As you tone and revolving power, Daguerreo-type was better.

Sir John F.W. Herchel-1839 – he coined the word “photography” James Clark Maxwell-1861 – he researched on colors.

a) 1907 – Lumiere color process was introduced, a panchromatic film was used but with blue, green, and red filter.

b) 1914 – US Eastman Kodak introduced two (2) color subtractive processes called Kodachrome. Twenty one (21) years later, a three (3) color process came out.

c) 1935 – Electronic flash unit came out. d) 1947 – Edwin H. Land introduced “POLAROID,” a one step

photography. e) 1960. Laser was invented making possible holography.

1482- The earliest known form of camera, Camera OBSCURA, was described by Leonardo da Vinci of Italy. An Italian, Geronimo Cardano- fitted a biconvex lens to the Camera Obscura in 1550 and in 1568, Daniel Barbaro suggested the use of a diaphragm to sharpen the image. By the end of the 17th century, small portable Camera Obscura that were equipped with reflex viewing system had been developed. The camera Obscura was first used successfully for photography in 1820’s by the French Scientist Joseph Nicephore Niepce, a French Chemist.


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1727- Johann Heinrich Schulze- a German physician was credited with the discovery of the light sensitivity of silver salt. 1777- Karl Wilhelm Scheele, a Swedish chemist investigated the darkening of silver chloride by light and found out that the salt was reduced to metallic silver. 1816- Joseph Nicephore Niepce, a French chemist, experimented with silver nitrate. On the same year he suppossedly produced image on paper from a negative, but he too was unable to remove the unexposed silver salts and secure a permanent image. He discovered that bitumen of Judea an asphaltic material became insoluble when exposed to light. Between 1824 to 1826, Niepce produce prints by coating the bitumen on metal plates, exposing it to light under a drawing or transparency and dissolving the unexposed bitumen. The plates was then etched with acid, which did not react with the remaining bitumen.1829- Niepce formed a partnership with Louis Jacquis Mande Dagurre, a French painter, to proceed on bitumen process but later Niepce died in 1833 and the work was continued with the partnership of Niepce’s son, Isidore.

Daguerre discarded the bitumen process and worked on his own procedure with the exposure of a polished silver plate to the vapor of iodine forming a sensitive layer of silver iodide After the plate had been exposed in the camera, the image was developed with mercury vapor. The process is then called Dagurreotypy. 1835- French Dagurre discovered that mercury fume will develop an invisible (latent) image on a silver plate that is sensitized with iodine fumes before exposure. 1835- William Henry Fox Talbot, an English archeologist and philologist, experimented with various salts of silver and found that silver chloride was more sensitive to light than was silver nitrate. Talbot process or Talbotype process, is a process wherein the paper was sensitized with silver iodide and after exposure was developed in Gallic acid. The modern photography is based on Talbot’s Negative – to - Positive principle. 1839- is generally known as the birth of photography. William Henry Fox Talbot explained a process he had invented (Calotype) at the Royal Society of London. The “Calotype” used paper with its surface fibers impregnated with light sensitive compounds.


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Sir John F.W. Herschel coins the word “photography”; (suggest “negative” and “positive” in the following year) and point out that image can be made permanent by dissolving away unexposed silver compounds with a solution of hyposulfite of soda (hypo or sodium thiosulfate), which he had discovered in 1819. 1839- Daguerreotype consisted of two wooden boxes perfected his photographic process. Images are made permanent by the use of hypo. The precision of details and exquisite beauty of these direct-positive images on silver plates make the Daguerreotype an immediate success. 1840- U.S. J. W. Draper is also one to produce photographic portraits using a lens with a diameter of five inches and a focus of seven inches. 1840, Australia-Hungary, J.M. Petzval designed the first lens specifically for photographic use. Its maximum aperture if f/3.6 makes it possible to take portrait exposure of less than one minute, launching the most widespread use of the Daguerreotype. The lens is produced the following year by Volglander for use in the first all-metal camera. 1843-1848- Major achievements with the paper-negative process are made by Hill Adamson and by various photographers on the continent beyond the reach of Talbot’s legal agents. 1845- F Von Marten, France, Invented the panoramic camera, wherein the lens is rotated about its optical center while a curved film is scanned by a slit. 1848- Abel Niepce de Saint Victor introduced a process of negatives on glass using albumen (egg white) as binding medium. 1850 – Louis Desirie Blanquart Evard introduced a printing paper coated with albumen to achieve a glossy surface. 1851- England. Frederick Scott Archer published a method of using collodion in place of albumen for negative on glass, “wet plate”. 1853- England. JB Dancer makes the first model of a twin lens camera for stereo photography, suggested by Sir David Brewster. 1858- France Nadar takes the first aerial photograph over Paris from a free balloon. 1861- First single lens reflex camera was patented by Thomas Sulton.

hpMalagamba


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1861- Scotland. James Clerk Maxwell publishes research in color perception and the three color separation of light. He also demonstrates additive color synthesis using hand colored materials in lantern slide projectors. 1880-The first twin-lens camera was produced by the British firm, R. & J. Beck. Eastman George, an American inventor, manufactured a dry plate process in 1880, the roll film in 1884 and made it available to market in 1889, and the Kodak camera in 1888, (6 ½ X 3 ½ X 3 ½) 3 ½ to infinity, 100 exposure. 1880- England. Sir William Abney discovers the use of hydroquinone as a developing agent. 1882. England Sir William Abney produces silver chloride gelatin emulsion for printing-out paper; it takes more than ten years for this and similar materials to supplant albumen paper. 1884- US. Eastman negative paper is introduced, consisting of a light sensitive emulsion or paper which after development is made transparent enough for printing by treating with hot castor oil. 1888- US John Carbutt begin the manufacture of celluloid base sheet film. 1890- full corrected lenses were introduced. 1895- The pocket camera was designed by Frank Brownell & called it “Brownie”. 1906- a plate was placed on the market that could reproduce all colors in equivalent shades of gray. 1907- Lummiere color process was introduced, a panchromatic film was used but with blue, green, and red filter. 1914- US Eastman Kodak Company introduce a two color subtractive process called Kodachrome. 1925- The German firm of Ernst Leitz brought our to market the popular camera, LIECA. 1928-The famous twin-lens reflex camera, the Rolleiflex was marketed by the German firm of Franke and Heidecke.


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1929- Germany. J. Ostermeier produce the first commercially acceptable self-contained flash bulb; an aluminu, foil sealed in an oxygen-filled bulb. 1932- The first photoelectric exposure meter is produced by Weston Electric Instrument company. 1934- Holland. The first wire-filled bulb was introduced by Phillips. 1935- A gas discharge tube emitting white light is introduced for electronic flash photography. 1935- the color process came out together with the electronic flash. 1936, Germany. Agfacolor reversal films is introduced the first three monopack film in which subtractive dye-formers are incorporated in each emulsion layer. 1947, US. Edwin H. Land introduce the Polaroid Camera- a one step photography with a self-processing black-and-white film that yields a positive print by the diffusion transfer reversal method. 1960- Laser was invented making possible holograms (three dimensional pictures). 1988- the arrival of true digital cameras. The first true digital camera that recorded the image as a computerized file was likely the Fuji DS-1P of 1988, which recorded to a 16 MB internal memory card that used a battery to keep the data in memory. This camera was never marketed in the USA. 1992-The first commercially available digital camera was the Kodak DCS-100. It used a 1.3 megapixel sensor and was priced at 13,000 dollars. 1995 -The first consumer camera with a Liquid Crystal Display (LCD) on the back was the Casio QV 10. 1996- the first camera to use compact flash was the Kodak DC-25 . 1999- the Nikon D1, a 2.74 mega pixel camera was the first digital SLR with a price of under 6,000 dollars. This camera also used Nikon F-mount lenses which means that film based photographers could use the same lenses they already own. In 2003, Canon introduced the 300D camera also known as digital rebel, a six (6) mega pixel and the first DSLR priced lesser than 1,000 dollars to consumers.


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IMPORTANT TERMS IN PHOTOGRAPHY: Relative Aperture- The speed or light gathering power of the lens equal to the ratio of the focal length to the diameter of it’s lens pupil or the relative brightness of the image produced by the lens as compared with the brightness of the subject. Depth of Field – The distance between the nearest and the farthest object in apparent sharp focus when the lens is focused at a given point. Hyper Focal Distance- The nearest distance at which the lens is focused at a particular F# to give maximum depth of field. Depth of Focus- The maximum permissible distance within which the film may be placed without exceeding the circle of confusion in order to produce the image sharp. Distortion- A general label referring to a particular distortion. Circle of Confusion- A disc form image of a point in the object the allowable circle of confusion is usually 1/1000 of the focal length of the lens in inches. Angle of View-The view of the subject subtended by two lines emerging from the corners of the film, extending to the center of the lens. Focal Length-The distance measured from the center of the lens to the film plane when the lens is set or focused in infinity position. Resolving Power of the Lens- The maximum angle of resolution. Focus- The means by which the object distance is estimated or calculated to form the image sharp. Lens- A medium or system which converge or diverge the light passing through it to form images. Positive Lens- A converging lens which is characterized by the fact that it is thicker at the center than the edges and therefore has a positive focal length. Forms the real image on the opposite side of the lens or the source of light. Negative Lens- A diverging lens which is always thinner at the center than the edge. Form an image virtual on the same side or source of light.


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Shutter- A contraption placed on the path of the light which passes through the lens. Filter- A homogeneous medium which (transmit and /or absorb) differentially wavelenght of the electromagnetic energy. Correction Filter- Those intended to alter the response of the film’s spectral sensitivity in term of brightness value as seen by the naked eye. Contrast Filter- Those intended to darken or lighten certain colors which would be produced of the same brightness without the use of such. Neutral Density Filter-Those which are intended to reduce the intensity of brightness

hpMalagamba Haze Filters- Those which are intended to minimize haze of distant objects due to atmospheric haze or bluish color of the sky. Polar Screen Filters- An optical slit which transmits light vibrating in the plain of the slit. Used primarily to control light reflected from highly polished surfaces, metallic objects & etc. Filter Factor-The ratio of the time of exposure with and without the filter for the same effective exposure. Flash Synchronization- The mechanical or electrical adjustments to make the shutter open and the flash lamp reach the peak of it’s flash at the same time. Parallax Error- The displacement of an image point when viewed at a different points of angle. Shape- Relates the general form, configuration, or outline of an individual object. Tone- refers to the brilliance with which light is reflected by an object without tone difference between photographic images, the shape of the object obviously could not be discerned. Resolution or Resolving Power-Is an expression of quality measured by visibly separated lines. It is expressed as the maximum number of the lines per millimeter that can be resolved or seen as individual separated lines. Any magnification beyond that required to make the line count for the resolution of the final print will decrease the image quality.


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Magnification-Described as changing by the use of optical instrument, the ratio between photographic images and the object. Shadow- The absence or reduction of light in a given space; caused by an opaque object blocking light rays. Light Meter- An instrument designed to measure the amount of light falling on or reflected from the subject. The information is used to make the aperture and shutter settings on a camera. Light Meter Acceptor- The eye of the camera metering system. Accelarator - One of the four subparts of a developer solution; purpose is to increase the activity of reducing agent. Bellows-A light tight folding accordion type sleeve that connects the camera body and the lens, also provides flexibility. Bracket Exposures-Making one or more exposure calculated to be correct. Flash Meter-A hand held light sensing device used to measure the burst of light from one or more electric flash unit. Bellows-The folding (accordion) portion in some cameras that connects the lens to the camera body (like the Mamiya RZ). Also a camera accessory that, when inserted between lens and camera body, extends the lens-to-film distance for close focusing or macro phtography. Some retains the automatic functions where some have to stopdown the lens for manual exposure reading. Bracketing-Taking a series of photographs of the same subject at different exposures to insure the "correct" exposure; useful when shooting in situations where a normal metering reading is difficult to obtain. Taking additional pictures of the subject through a range of exposures-both lighter and darker-when unsure of the correct exposure.Some top cameras have provision for automatic bracketing, while manually you can bracket by the use of, say, adjust apertures or shuttle speeds setting or both, manually influent the ASA setting or even adjust the flash output power etc.. Burning-In- is a darkroom process that gives additional exposure to part of the image projected on an enlarger easel to make that area of the print darker. This is accomplished after the basic exposure by extending the exposure time to allow additional image-forming light to strike the areas in the print you want to darken


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while holding back the image-forming light from the rest of the image. Sometimes called printing-in. Cropping- Printing only part of the image that is in the negative or slide, usually for a more pleasing composition, in medium format, esp the 6 x 6, some form of cropping is necessary for publishing on A4 magazine format. It may also refer to the framing of the scene in the viewfinder. Diaphragm- an adjustable device inside the lens which is similar to the iris in the human eye; comprised of six or seven overlapping metal blades; continuously adjustable from "wide open" to "stopped down"; controls the amount of light allowed to pass through the lens and expose the film when a picture is taken; a]so controls the amount of depth of field the photograph will have. Dodging- holding back the image-forming light from a part of the image projected on an enlarger easel during part of the basic exposure time to make that area of the print lighter. Double Exposure- Two pictures taken on one frame of film, or two images printed on one piece of photographic paper. Some cameras can have double exposure level depressed with multiple exposures one even with a motor drive. Tripod- a three-legged supporting stand used to hold the camera steady to prevent blurred image. This is useful when using slow shutter speeds and/or telephoto lenses. Another is the monopod, single leg tripod. Vignetting (/v�n�j�t�ŋ/; French: "vignette") is a reduction of an image's brightness or saturation at the periphery compared to the image center. The word vignette, from the same root as vine, originally referred to a decorative border in a book. Later, the word came to be used for a photographic portrait which is clear in the center, and fades off at the edges. “LIGHT” its Nature and Sources

It is a radiant electromagnetic energy that can be seen by naked eye. 186,000 miles/sec. – velocity/ speed of light 16,000 to 18,000 ft./sec. – bullets speed “Effect” of light is what we see. Electromagnetic spectrum – band of colors/energy “WAVELENGHT”- is the distance measured from the crest (highest point) to the wave of the next succeeding crest while frequency is the number of waves passing in a given point in one second. The product of two is the speed of


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travel. Wavelenght is measured by the angstrom unit or in terms of milli-microns (English system of measure) or nanometer (Metric system of measure) which is equivalent to one over one millionth of a millimeter. The final effect a radiant energy may have on an object is to be converted to another wavelength. This conversion is known as luminescence. There are two (2) types of luminescence:

1. Fluorescence-is the ability of an object to convert one wavelength to another as long as the active energy source is irradiating the object.

2. Phosphorescence-is when the object does not only converts the wavelength while being irradiated but continuously reflect the new wavelengths for a period of time after the energy source is removed.

Invisible light rays to our eyes: 1) Cosmic rays 5) Ultra-violet rays 2) Gamma rays 3) X-rays 6) Infra-red rays 4) Hertzian wave .01-30nm. � X-rays 30-400nm. � ultra-violet rays (UV) (below the red wavelength) 400-700nm. � visible light (VL) 700-1000-2000nm. � infra-red rays (IR) This all are capable of introducing change into the photographic emulsion. COLOR IN PHOTOGRAPHY

White light- is photographic ray without a tint of any color or shadow. Fundamentally and photographically, the subdivisions of white light are the PRIMARY COLORS: Blue; Green; and Red

(Primary)

Red

Magenta Yellow (Secondary) (Secondary)

(Primary)Blue Green (Primary)

Cyan

(Secondary)


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Figure 1. Primary and Secondary Colors

The respective complementary colors of the primaries are yellow, magenta, and cyan, each being a combination of the other two primaries. When a primary color and its complementary (secondary) color are combined to bring all basic color together again, the result is White Light.

The ADDITIVE PRINCIPLE If we get three projectors with beams of lights projecting individually blue, green and red and have the three beams overlap over the other, we will note that the portion where the blue and green lights merged over the other it will produce a cyan color, the green and red lights a yellow color, and the red and blue lights a magenta color. At the center where the blue, green, red light, were combined in proper ratio, we see white light. In this aspect, cyan, yellow and magenta are known as the three secondary colors of light. For practical purpose, white is the presence of all colors while black is the absence of all colors or absence of light.

a) Blue + Red ═ Magenta b) Green + Blue ═ Cyan c) Red + Green ═ Yellow

The SUBTRACTIVE PRINCIPLE This time, the light beams of the three projectors will be covered each with cyan filter, yellow filter and magenta filter and have the beams of light projected one over the other. The cyan filter will transmit blue and green light but absorbs red from white light. A yellow filter will transmit green and red light but absorbs blue from white light. Similarly, a magenta filter will transmit red and blue light but absorbs green from white light. At the center where the three beams of light are merged together will produce black. In simple terms, cyan is the complementary of red, yellow is the complementary of blue, and magenta is the complementary of green.

a) Magenta + Cyan ═ Blue b) Cyan + Yellow ═ Green c) Magenta + Yellow ═ Red


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“White” – presence of all colors “Black” – absence of all colors Color Filter – work in such a way that it will transmit its own color and absorb all other colors. Blue Filter – additive - transmits Blue

- admits Green and Red

White Light

Cosmic Gamma X-ray

Ultra- Violet

Infrared Hertzian Radio waves

Long Electrical Oscillations

Violet Blue Green Yellow Orange Red

400 460 510 580 600 680 700 “RAT LAW” R - Reflection A - Absorption T - Transmission UV – Reflected IR - Reflected ex. Fluorescence ex. Phosphorescence method � when light is put off it is still seen or radiate light. Manners of Bending of light: 1. Reflection – the rebounding or the deflection of light as it hits the surface. a) Regular reflection b) Irregular reflection 2. Refraction – bending of light when passing from one medium to another


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3. Diffraction – bending of lights when it strikes the sharp edge of an opaque object. ( light does not pass through) - occurs when light passes through a narrow slit. If there were no diffraction, the image of the slit would be geometrically similar to the slit itself. ex. Double Diffraction General rule: Irish Diaphragm – Smaller Diaphragm – opening � it has a greater depth of field. Exception: Diffraction Types of materials: 1. Transparent – allows light to pass through its medium, objects on the opposite side is clearly visible. 2. Translucent – allow light to pass through but visible. Objects are not clearly visible. 3. Opaque – does not allow light to pas through its medium. Sources of light: Natural – sunlight, moonlight, lightning & etc. Artificial – a) continuous radiant – fluorescent & candle b) Short radiation – flash units 1. Photo floods – an electric lamp using an excess voltage for sustained illumination. (1930 – panchromatic film) - inserted in a metal reflector, fit with standard socket & operate in ordinary house current and has a life of 3 hours. 2. Flash bulb

3. Electronic flash

SUNLIGHT/DAYLIGHT: Color of Day light: Factors affecting the color of daylight: 1. Atmospheric vapor – tends to color the daylight orange. 2. Atmospheric dust filters – the sun rays and scatters rays of the shorter wavelengths more than those of longer wavelengths. (Blueness of the sky due to scattering effect of the blue light) 3. Part of the light reaching the subject does not come directly from the sun but reflected. (affected by the color of the reflector.) Daylight Classification According to Intensity:


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1. Bright sunlight – objects in open space cast a deep & uniform or distinct shadow. Objects in open space appear glossy & the colors are saturated. a) direct sunlight } coming from the sky which serves as a reflector. b) Reflected light } 2. Hazy sunlight – cast a transparent shadow. 3. Dull sunlight – no longer cast shadow. a) cloudy bright – about really to rain b) cloudy dull

Sensitized Materials: - a general term which refers to materials which are sensitive to

light. ex. a) Film b) Photographic paper Gelatin – prevent scratches on emulsion Coating of silver halides silver salts silver nitrate silver chloride } silver bromide } Photo paper silver iodide } Spray anti-halation backing -Prevents reflection of light or formation of “HALO” Base or acetate Sensing Cell – measures the amount of light from the subject. When correct amount of light is provided to expose film, the flash shut – off. Larger Electronic Flash – wide angle, normal, telephoto lens. Adjustable to different angles for bounce lighting. “Color separation” FILMS Film- is a sheet or strip of thin, flexible transparent material (acetate or polyester plastic) coated on one side with a light sensitive emulsion capable of recording an image as a result of exposure in camera. Six (6) layers of black & white film 1. Top Coat – is a layer of hard gelatin that insulates the emulsion against scratches. 2. Emulsion layer – where the image forms, consists of gelatin containing light-sensitive crystals of silver halides.


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3. Subbing layer – special glue like gelatin, adheres the emulsion to its support below. 4. Support – provides a strong but flexible plastic (cellulose acetate) base for all the other component layers of the film. 5. Second Adhesive layer – bonds the support to the anti-halation backing below. 6. Anti-halation Backing – contains dye that prevents light from reflecting off the support off the camera itself and back onto the emulsion, which reflections could create halos around bright areas of the images. Six (6) basic characteristics of black & white film 1. Color Sensitivity – the ability of the film to respond to certain wavelength of the light in the visible portion of the electromagnetic spectrum – and therefore unable to represent these effectively in black & white. 2. Contrast – a films ability to record values of gray - that is white through gray to black. a) Films - that record only a limited number of values are referred to as contrasty, while those that record a greater number of values are considered to be not contrasty. Ex. Kodalith - (Eastman Kodak Product) records only elements that are either black or white. (Normally used in graphic studios) 3. Light Sensitivity – or the film’s speed, as it is determined by the size of the silver halide crystals in the film’s emulsion. The larger the crystals are, the greater sensitivity and the other way around.

This means that a film with high sensitivity (fast film) requires less light to produce an image than one with low sensitivity (slow film).

4. Grain – (size of the light sensitive crystals in a film’s emulsion determine the nature of its grain). � It is the textural quality of tones in a print that are produced when microscopic particles of silver clump together during development. � When choosing the best film for a particular situation, the photographer must consider not only whether it will give satisfactory exposure under the conditions of available light but also the kind of image it will create. Since it is impossible to attain both maximum speed and the finest visual quality simultaneously; photographers often compromise by using a MEDIUM SPEED film. Graininess – relates to the degree of enlargement made from the original size of the negative.


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5. Resolving Power – refers to the film’s ability to distinguish between closely spaced lines or the ability of the film to reproduce fine details. Ex. photographing a chart with areas of parallel lines – lines is either close or far (not uniform in distance) - cannot be distinguish as lines bus seen as tone of gray. 6. Acutance – is a term that describes a film’s sharpness. - A film’s sharpness as distinguished by the degree of tonal gradation separating light and dark areas in photographic image. STRUCTURE OF COLOR FILM RAW FILM COLOR POSITIVE Blue sensitive emulsion Yellow image Green sensitive emulsion Magenta image Red sensitive emulsion Blue-Green image Anti-halation backing Safety film support. Types of film (black & white) according to Color or Spectral sensitivity: 1. Monochromatic (blue sensitivity) – sensitive to UV and blue color only. 2. Orthochromatic film – sensitive to UV to blue and green light. 3. Panchromatic – sensitive to UV, blue, green, red or all colors, it has a widest range of spectral sensitivity. 4. Infra-red films – sensitive to UV, blue, green, red or all colors or infra-red rays. 3 F’s Infra-red Photography 1. Film 2. Filter 3. Focus – to adjust to the longer wavelengths of infrared. (700 to 1000 nm) “Suffix” color – negative material “Suffix” chrome – positive material ex. Film of a Movie Emulsion Speed - all films except those used in instamatic camera have a film speed or emulsion speed. Indications for emulsion speed: 1. ASA rating – American Standard Association (expressed in arithmetical value) 2. DIN rating – Deutsche Industrie Normen (expressed in logarithmic value) 3. ISO rating – International Standard Organization (expressed in arithmetical value) 4. JSI – Japanese Institute of Standards 5. BSI- British Standard International.


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Major Classifications of Film speed by average ASA & DIN ratings are: a) Slow films – about 32 ASA (16/10 DIN), which require a high light level; b) Medium films – about 125 ASA (22/10 DIN), which are used in average or normal light situations, such as outdoors on a sunny day. (The most common). c) Fast films – about 400 ASA (27/10 DIN) which are needed when the light level is low – very cloudy, rainy day, or indoors under available light. - or when fast shutter speed is required to stop action. d) Extra-fast films – About 800 ASA (30/10 DIN) which are used only when the other types of film are too slow – under the dimmest light conditions or when the fastest possible shutter speeds are necessary. ASA number - is not absolute. Even manufacturers are conservative in assigning any number to a film because they feel that slight over-exposure is less of an evil than under exposure. Photographers can alter the ASA while processing the film by manipulating variables temp. of solutions, developing time, type of developer and the method of agitation. ASA12 lesser sensitive DIN 12 ASA 25 15 ASA 50 18 ASA 100-plus x 21 ASA 200-duoble xx 24 ASA 400-Tri xxx 27 ASA 800 ASA 1600-more sensitive 33 ASA 100 3 lamps ASA 200 2 lamps ASA 400 1 lamp PHOTOGRAPHIC PAPERS 1. Chemical contents a) Bromide papers – used in enlarging or projection printing b) Chloride papers – used in contact (size of negative and the same size of print) c) Chlorobromide papers 2. Contrast Range No. 0 – excessive high No. 1 – exposed low contrast No. 2 – used in normal exposed (contrast negative) No. 3 – used in under exposed or high contrast negative


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3. Physical Characteristics a) Surface – glossy-semi matte, matte b) Weight or thickness – single weight double weight c) Color – white cream. CAMERA Types of Camera 1. View Camera – a large camera that is mostly used in studios for portrait pictures. - used for advertising, architecture, and other commercial works. - can make large sharp picture but large and clumsy and have to be transport into the scene of the crime. 2. Graphic Camera – is also a view camera, but it is smaller and designed to be folded up when not in used. A 4 inch x 5 inch – graphic camera was the favorite camera of police & newspaper photographers. Advantages of Graphic camera 1. The image can be observed in the ground glass before it is taken. 2. The negatives can be printed by the contrast method. 3. By means of holders, only a single film has to be taken if that is all that is needed. ex. century graphic camera - uses 2 ¼ inches x 3 ¼ film -use120 size film which can take 10 pictures. 3. Twin lens reflex camera – a roll film camera that uses two lenses: viewing lens, taking lens This camera is useful in police work particularly in traffic accident photography, color or black & white film can be used. In taking picture, the photographer holds the camera at the level of his waist and looks down into a ground glass with a mirror in it. ex. a) Rolleiflex – well known twins lens reflex camera b) Rolleicard c) Yashikamat – made by a Japanese company Disadvantage: 1. Pictures are squares and do not enlarge at conventional size. 4. Single lens reflex camera – � a kind of camera where in the photographer looks through the lens the actually takes the picture by means of a mirror.


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� when taking picture, the mirror moves up out of the way just a fraction of a second before the shutter opens. � most of this type of camera are in 335 mm size. ex. a) Hasselblad – Swedish made } Both are larger b) Bromica - Japanese made } ones � 2 – ¼ x 2 ¼ - very expensive and their advantages does not justify their high cost for police work.

4. Miniature 35 mm cameras German Leica – was the first 35 mm camera was designed to use motion picture film manufactured in great quantity for the cinema and very cheap. 2 Principal kinds of miniature 35 mm camera a) range finder – (Leica and Contax) b) single lens reflex � most 35 mm camera � uses a moving curtain instead of a shutter. � Can use large of lens attachments Advantage: a) Cheap b) Handy c) Capable producing photographs as good as that of a large camera. Disadvantage: a) More care and more painstaking in processing should be considered. b) User must use enlarger since negatives are too small (1” x 1- ½ “). 6. Digital Cameras Five (5) Basic features of a Camera: The following are the parts that enable the instrument to perform properly: 1. Viewing system 4. Aperture 2. Focusing system 5. Lens 3. Shutter

A) Viewing System – normally consisting of a lens or set of lenses, permits the photographer to see that part of a scene the camera can record on the film. This will also view the scene it will record and will frame the area his camera can record when pointed in a certain direction.


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Note: There are significant differences between the eye and the camera – eye as it looks at the subject, it is moving constantly from one point to another. (Composite of many individual views integrated into a single visual experience) while the Still cameras as distinguish from a movie camera – record all that it views of a given subject in one image. Parallax Error – (in view finder camera) is the discrepancy between the view finder lens and that projected onto the film by the camera’s picture taking lens. Instamatic: 1. – Fixed diaphragm & lens opening 2. – Fixed focus 3. – Fixed shutter speed B) Focusing System – the setting of the proper distance in order to form a sharp image. Works mechanically to move the lens closer to or farther away from the film, & make the image sharp or blurred as it strikes the film surface. (Do not move the camera) (The subject should not move) How to determine focus of camera: 1. Scale bed or focusing scale – 2. Range finders – (coupled with the mica finder) a) Split image – out of focus using ground glass b) Co-incident image 3. Ground glass with Penta prism C) Shutter – a kind of shield or curtain, opens and closes at various speeds to control exposure; that is, it measures the length of time during which light enters the camera and strikes the film surface. D) Aperture – like a shutter is a device for controlling the amount of light. It works not in a measured unit of time, but by the measured units of time, but by the measured size of the opening through which light enters the camera via the lens. The aperture usually has a form of over lapping thin metal leaves arranged in a circle, which are called the diaphragm. Diaphragm – a mechanical device, it can be made to expand or contrast and thus to admit into the camera greater and smaller amount of light. E) Lens – gather light rays reflected from the scene or subject being photographed and project them onto the film surface as a completely reversed image. Lens-is a medium or system which converges or diverges light passing throw it to form images. Lens is considered as the eye of the camera.


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LENS DEFECTS: Chromatic Aberration – a defect on simple lenses that causes the light ray of different colors to focus on different planes, which results a blur on black & white and fringed or haloed with extraneous color on colored images. Spherical Aberration – occurs when the light rays that passed by the outer portion of a lens and those from the lens center do not converge at the same focal point. Coma Aberration - occurs when the light rays passed obliquely through the lens, instead of parallel to the lens areas, resulting in poor marginal definition or the inability of a lens to produce, equal magnification in all areas of the lens. Astigmatism – an aberration that occurs when the lens cannot bring into common focus lines on the same plane that are horizontal and those that are vertical or the in ability of the lens to project a sharp image of lines running at angles to each other, almost as if the lens had one focal length for horizontal and another far vertical projection. Anastigmat –a term given when the lens is corrected for a minimum separation between the horizontal and vertical focuses. Astigmatism can be lessened by using a smaller opening, when the image is projected only by the center area of the lens. Curvature of the Field – when the flat-plane image comes out slightly curved, like a saucer. Solution: A focus bet. The two point of sharpness and a relating small aperture. Distortion – a general label refers to a particular kind of distortion. Curvilinear Distortion – is an aberration that causes the lens to render straight lines in the subject as curved lines in the image. Two types of Curvilinear Distortion: 1. Barrel Distortion – when the image lines curve out forward the picture edges, caused by placing the diaphragm in front of the lens. 2. Pincushion Distortion – when the image lines pinch inward like a warp waist, caused by placing the diaphragm behind the lens.


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Curvilinear distortion is corrected by placing the diaphragm (control of –f/stops) near the center of the lens combination. single lens – diaphragm placement in front of the lens. Flare – a stray or scratched light not controlled by the lens Optical Flare – internal reflection & double images. / pear shape called Coma Ghost image – a secondary image sharp or not, caused by wrongly placed lamp, or due to window reflection. Coating – This is effective in subduing optical flare. Mechanical flare – reflection from a bright spot close to the lens - from camera lens mounting, caused by parts of diaphragm, shutter or mount that have worn shiny and can be prevented by blackening inner surface thoroughly attaining minimum distortion & fewer common lens defects. ` “Super sensitive meter” – 0.14 foot candles – measure moonlight “Spot meters” – takes reading great distances from the camera. Long lens meters” – instead into the lens barrel, reads the light by the lenses. Methods of Reading: Measuring light quality by meter reading: 1. Reflected light – light that reflects from the subject 2. Incident light – intensity that falls on the subject, read by painting the meter away from the subject. GRAY CARD Filters – transparent piece of glass or gelatin used to alter or control the color of light reaching a film during exposure. “Neutral Density filters” – no color characteristics; reduce light transmission & prevent over exposure of fast films. Gelatin Filters – with any color you want Types of lenses as according to their degree of correction: 1. Achromatic lens – a lens corrected for chromatic aberration. 2. Rapid Rectilinear lens – lens corrected for distortion. 3. Anastigmat lens – lens corrected for astigmatism. 4. Apochromat lens – lens corrected for astigmatism but with a higher correction to color. Three (3) Basic shapes used to prepare a lens to refract light:


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a) Flat b) Convex c) Concave Converging or Plus lenses - refracted from these lenses is reflected to a selected focal plane. a) Plane convex b) Double convex c) Meniscus convex Diverging or Minus lenses – cause the refracted light to spread. a) Plane concave b) Double concave c) Meniscus concave Principal plane Optical Center – the point at which the vertical and horizontal axis cross. Multiple Element Lenses – refers to each individual lens. Element - when several lenses are used together to from a given camera liens. 35 mm SLR – can have as few as three elements and as many as 16 elements. Elements making up a lens maybe. Positioned and arranged precisely in the barrel: a) Cemented together } grouping of lens b) Positioned by themselves} element RANGE FINDERS: Range-finders – is a mechanism that measures the angle of the convergence of light coming from a subject as seen from two apertures. There are two types of range finders. a.Split-image – through the range finder, the image of straight line in the object appears to be cut into halves and separated from each other when the lens is not in focus. When the images of the lines are aligned, the lens is in focus. b. Co-incident image – through the eyepiece, a single image is seen double when subject is out of focus. Make the image coincide and the lens is in focus. c. Ground glass – is focused by directly observing the image formed at the ground glass, screen placed behind the taking lens. If the image formed is blurred, fuzzy, or not clear, the lens is out of focus. Make the image sharp, the lens is in focus.


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d. Zone – this is possible in wide angle lenses only. There are only three setting for focusing. One for close distance (approximately 3-6ft) another for medium distance (approximately 6-15 ft) and finally for distance objects (approximately 15 infinity).

Classification of Lenses according to Focal length: 1. Wide Angle – focal length is less than the diagonal of its negative material. 2. Normal Lens – focal length is equal to but not more than twice the length of the diagonal of the negative material. 3. Long or Telephoto lens –it has a focal length of more than twice the diagonal of the

negative material. Characteristics of Telephoto lens: - decreased depth perception - increased scale but reduced area coverage - Image quality deteriorates, esp. when subject is in motion. - Angle of view less than 45 degrees. 4. Zoom Lenses – lens of variable focal length that can be adjusted continuously by the movement of one or more groups of elements in the lens system – (variable focus lens). (TV, motion pictures) 5. Fisheye Lenses- a lens with 180 degree angle of coverage.

Exposure by Light Meters: CAMERA – may contain 7 elements & 6 groups. (2 elements cemented together) (5 elements positioned separately) Focal length – is the distance from the optical center of the lens to the focal plane when the lens is focused at infinity. Nodal point – refers to the exact center of the glass. Multiple (compound lens) – difficult to determine its center.


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number of elements } Factors affecting nodal shapes } point location. grouping } Scientific definition of focal length FL = the distance from the rear nodal point of the lens to the focal plane. Measured in millimeters Most standard 35 mm SLR camera has a focal length of 50 mm. And vary slightly from 47 to 55 mm, depending on the brand. Angle of View – is the view of the subject subtended by two lines emerging from the corner of the film extending to the center of the lens. Resolving Power of the lens – refers to the maximum angle of resolution. “The shorter the focal length of the lens, the wider is its angle of coverage”. “The longer the focal length of the lens, the narrower is the angle of coverage”. Size of the image which is refracted through the lens is determined by its focal length. Focal length less than 40 mm – are wide angle & those above 60 mm are telephoto lenses. Angle of view of the lens is determined by its focal length.

Other parts/elements of the Camera: F) Box, body, or container G) Film H) Film advance SHUTTER Two (2) kinds of Shutter 1. Leaf Shutter – located in the lens (between the lens shutters) 2. Focal Plane Shutter – (operate near the focal plane of the camera) directly in front of the film. Leaf Shutter – consists of a series of tiny metal eaves or blades which, in a closed position, overlap to prevent the light from entering the camera. The leaves are controlled by a guard and taut – spring mechanism & the Shutter to open, the spring must be cocked – that is be in a taut position. (Some cameras cock the spring automatically other manually). - when the spring is released the leave, moves away from the center of the lens (fig 98) permitting a tiny amount of light to enter the camera, it continues


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until leaves have opened to their fullest extent and the maximum amount of available lights pour in (fig.100). Focal Plane Shutter – consisted of an opaque curtain interrupted by a slit a spring mechanism pulled the slit past the film, in its transit exposing the film to light. - Low spring tension produces long exposures ex. (1/10 of second) (1/1000 of a second fast) Difference between the leaf Shutter and Focal Plane Shutter The manner in which the light is permitted to strikes the film. When a Leaf Shutter is used – the exposure light is spread over the whole negative, but it builds up intensity to a peak and then diminished… while the Focal Plane Shutter – maintains constant light, while allowing the negative to be exposed sequentially in segments. - can function with whatever lens may be put into the camera - permits viewing into the lens - Mechanism moving in a single direction * Creates a time lapse bet the exposure of the first section and the last – no prove when photographing fixed object - produce elongation of moving objects. (Jacques Henri Lartigue) - but converted in modern 35 mm camera. SHUTTER SPEED – control the duration of light. B – setting or B – Bulb setting -4 +4 Shutter speeds 1/125 or 1/30 1 – second (slowest) Shutter speeds: 4, 8, 15, 30, 60, 125, 250, 500, and 1000 Kinds of Shutter: 1. Placed before the lens 4. Placed near the focal plane in front of the 2. Placed behind the lens sensitive material. 3. Placed between the lens EXPOSURE Exposure – is the product of illumination and time. (lens & diaphragm opening) “Shutter Speeds” controls speeds Exposure: * The lower paper grade the faster is the speed * The denser the negative the longer is the exposure.


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Note: The higher the wattage of the lamps and the closer is the distance from the negative the shorter is the exposure time. Composition- is the process of placing your subject into the frame. Rule of thirds- this is when the photographer divides the frame into nine squares and place his/her subject in proper proportion or angle. LABORATORY PROCESSING: 1. The print must stay in the solution for not less than 45 seconds but not more than 1 minute. (In motion or while agitating) 2. STOP BATH 10 – 15 seconds 3. Fixing 4. Washing Enlarging: Test strip photometer Step wedge density measurements FACTORS TO BE CONSIDERED IN THE COMPUTATION FOR EXPOSURE: 1. ASA RATING

2. Lightning Condition

3. Type of Subject (bright, normal/ordinary, or dull subjects)

USING A FLASH UNI GN or guide number

ASA 100 } 110/9ft =- distances in feet

GN – 110 } 10.2 or f – 11

(lamp or to subject flash unit)

SYNCHRONIZATION – synchronized flash unit with the shutter.

125/sec. below – you will be able to synchronized your flash & shutter.\

CHEMICAL PROCESSING:

1. Development – is the process of reduction. Exposed silver halides are reduced into metallic silver. There is a separate developer for film (D-76), and another for paper (Dektol). The factors that affect developing time are: agitation, temperature, concentration of chemicals, and exposure.

2. Stop-Bath – an intermediate bath between the developer and the fixer. It is usually a combination of water plus acetic acid or just plain


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water. Primarily, its function is to prevent the concentration of the two chemical solutions.

3. Fixation – the process of removing unexposed silver halide remaining in the emulsion after the first stage of development of the latent image. The usual composition of an acid fixing solution are solvent silver halide known as hypo, an

anti-staining agent like acetic acid, a preservation like sodium sulfate, and a hardening agent like potassium alum. 4. Washing on running water

Processing method – negative-positive method, reversal method Film Processing: TRAY METHOD


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Film Processing: TANK METHOD Chemical composition of developer:

1. Reducers or developing agents – Elon, Hydroquinone 2. Preservative – sodium sulphite 3. Accelerator – sodium carbonate 4. Restrainer or (prevents fog) – Potassium bromide

1 pack or can of D-76 dissolve in one gallon of water (5 to 6 minutes)

Chemical composition of a fixer:

1. Dissolving agent – Hypo or Sodium thiosulphate 2. Preservative – Sodium sulphite 3. Neutralizer – Boric acid, acetic acid 4. Hardener – potassium alum

Factors that affect developing time: 1. Characteristics of Negative material 2. Strength and composition of the developer 3. Temperature of the developing solution 4. Agitation or stirring during development

M. ENLARGING TECHNIQUE

After processing an exposed film into a negative, the next step would be to turn the negative into a positive print or copy. This could be done by either contact printing or projection printing. For contact printing, a contact printer is used while in projection printing an enlarger is needed. There are four essential parts of an enlarger: a base and stand, a lamp house, a condenser or diffuser, and a lens, accessories of the enlarger are: a negative holder and an easel (paper holder). The following are the steps in enlarging:

1. Preparation of the darkroom, chemicals and the enlarger. 2. Put off white light, switch on red light. 3. Place the negative in the negative holder with the dull side of the

negative facing down. 4. Insert the negative holder into the enlarger. 5. Switch on the enlarger’s light. 6. Adjust the easel to the desired size of the photograph.


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7. Focus the lens of the enlarger. Focusing is done by first opening the lens diaphragm fully. If after the image ha been focused, and the density of the negative lens of the enlarger must be stopped down a little bit.

8. Switch off the light of the enlarger. 9. Insert the photographic paper in the easel with the shiny side facing

up. 10. Make the exposure. 11. Immerse the exposed photographic paper in the developer. The usual

developing time for a normally exposed paper is about 1 to 1 ½ min. 12. Transfer the developed print in the stop bath for about 30 seconds. 13. Place the prints in the acid fixer. The fixing time is about to 30

minutes. 14. Wash the print in running water for about 20 to 30 minutes. 15. Drying 16. Mounting

Remedying chemical defects in negatives:

a) Underdevelopment –Intensifier b) Overdevelopment – Reducer c) Stains – Stain remover

Frequent faults in printing:

1. Blurred exhibits 2. Muddy and mottled exhibits 3. Yellowish exhibits 4. Dark exhibits 5. Light exhibits 6. Harsh exhibits 7. Flat exhibits 8. Fogged exhibits 9. Blemishes exhibits 10. Distorted prints

microdol x – film developer

dektol – paper developer

1 can or 1 pack of Dektol dissolved in One (1) gal of water Stock solution.

1 : . 2 1 part stock solution 2 parts – H2O

(2.5 to 3 minutes)-developing time.

FIXERS


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Chemical components: 1. Hypo (sodium thiosulfate) – serves as the dissolving agent

2. Sodium sulfate – preservative

3. Boric acid } both

4. Acetic acid (with anti-staining agent) } neutralizer

5. Potassium aluminum (tawas) – hardener

The Fixer for film & paper are the same (10-15 minutes)

WASHING - -to remove hypo to prevent faded photograph

PRINTING – The shiny sides of the negative and the photographic paper should be facing each

other.

“Emulsion side of the negative facing emulsion or sensitive side of the photographic

paper”

1) 5.6 minutes developing time using D-76

Ratio of chemical 1:1

2) 10 seconds – stop bath

3) 10 minutes fixing time

5 – Students maximum / enlarger

Reflected Method – light source UV – light usually used to expose film also UV.

Fluorescence Method – by the use of a filter, (rotten filler #2B) visible lamp.

� UV photography needs the use of the darkroom.

Infra-red – uses infra-red film, or infra-red

a) Rotten filter # 88, 89 – very deep red – in color

Totally Dark or Black – out Photography – does not need filter but you should use infra-

red Flash.

Development for Infra-red Photography – should be done similarly the same with the

development of black and white film.


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Lesson Seven :

Documenting the Crime SceneDocumenting the Crime SceneDocumenting the Crime SceneDocumenting the Crime Scene


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NOTES


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Duration of Instruction

Eight hours - Two (2) hours lecture

- Six (6) hours practical

Lesson Goal

The goal of this lesson is to provide participants with an overview of the various methods of documenting a crime scene, to include note taking, sketching, and photography.

Performance Objectives

At the conclusion of this lesson, participants will be able to:

7.1 Identify at least six (6) essential items of information that should be included in a crime scene specialist’s notes.

7.2 Identify at least six (6) pieces of information that should be included on a crime scene sketch.

7.3 Identify three (3) methods used in sketching a crime scene.

7.4 Name the two (2) adjustments on a camera that control the amount of light that reaches the film.

7.5 Identify at least two (2) reasons why photographing the crime scene is important.

7.6 Identify the importance of film speed and film type.

7.7 List the six (6) steps used to load film into a 35 mm camera and the three (3) steps used to unload film from a 35 mm camera.

Introduction


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The three most common methods of recording a crime scene are: note taking, sketching, and photography. A detailed record of the crime scene and of the actions taken during the search of it, help the crime scene specialist to accurately recall events and to identify items of evidence later in a court of law. The notes taken, sketches and photographs made by the crime scene specialist during the search for evidence also serve as a valuable reference concerning the details uncovered during the search and the thoroughness of the method.

Presentation of Content

�� Lesson Objective #7.1 Identify at least six (6) essential items of information that should be included in a crime scene specialist’s notes.

I. Note Taking

The crime scene specialist’s notes are his/her personal record of the search for evidence. The objective of note taking at a crime scene is to make detailed notes that will remain fully meaningful even months after the event. Oftentimes, a note that is completely clear to the writer a short time after being made later becomes unintelligible.

The notes taken should begin with the crime scene specialist’s name and assignment to the case. Notes should be supplemented by sketches and photographs of the scene. Notes should be recorded in the order that the observations they pertain to are made, and will not necessarily be in logical order. During the initial stage of the recording process, it is important only that the notes are complete, as the crime scene specialist will later reorganize the information during the writing of the formal report.


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A. Essential Items of Information to be Included During Note Taking

1. Dates, times, and locations

The date and time of the crime scene specialist’s assignment to the case should be noted. The exact time of arrival, exact location of the crime scene, light and weather conditions, the names of any officers contacted, and names of other persons on the scene of the crime at the time of the crime scene specialist’s arrival should be noted.

2. Detailed Description of the Victim and his/her Clothing

The name, age, height, weight, complexion, and color of hair and eyes of the victim need to be included in the notes. Outer garments worn by the victim should be described in terms of the type of garment and color.

3. Wounds the Victim has Received

The exact location of a wound or injury, its type, size, and in the case of a bruise, its color need to be included in the notes.

4. A General Description of the Crime Scene

The crime scene specialist should note any damage to items, any apparent disturbance of the normal arrangement of furniture or other objects, and the presence of objects that seem unusual in the context of the scene.

5. The Type of Camera and Film Used in Photographing the Crime Scene

As each photograph is taken, a note should be made that includes the “f” stop of the camera, shutter speed, distance focused, direction in which the camera was faced, flash if used, object or area photographed, and the time that the photograph was taken. The disposition of the film (the location that it was sent for processing) should also be noted.

6. Discovery of Each Significant Item of Evidence

Included should be the description of the item, the time it was discovered, by whom, the exact place of its discovery, how it was marked, the type of container it was placed in, how the container was sealed and marked, and the disposition of the item after it was collected.

7. The Failure to Locate Items

Included should be the absence of items that would normally be associated with the crime that is being investigated, the area of the crime scene, or with any deceased victims (i.e., an item of clothing is missing from the victim’s body that could not be located at the scene of a crime.)


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B. Use of the Crime Scene Specialist’s Notes

Notes are valuable not only as an aid to an accurate recall of events to be testified to in court, but also to furnish the raw material needed in the written formal report of the case. A different notebook should be used for each separate case and the notebooks should be kept permanently in a safe place.

�� Lesson Objective #7.2. Identify at least six (6) pieces of information that should be included on a crime scene sketch.

II. Crime Scene Sketches

Photographs alone are not sufficient for the adequate recording a crime scene. A crime scene sketch will complement the photographs and notes made during the crime scene search. The purpose of a sketch is to portray the information accurately, not necessarily artistically. It is not required that the crime scene specialist have any artistic ability in order to construct an adequate sketch of a crime scene. Crime scene sketches clarify the appearance of the scene and make it easier to comprehend.

A. Information to be Included in the Sketch

The sketch should include at least the following information:

1. The crime scene specialist’s full name and assignment.

2. The date, time, crime classification, and report number.

3. The full name of any person who assists in taking measurements.

4. Address of the crime scene, its position in a building, landmarks, and compass direction.

5. The scale of the drawing, if a scale drawing has been made.

6. The major discernible items of physical evidence and the critical features of the crime scene. The location of such items is indicated by accurate measurements from at least two fixed points, or by other methods discussed below.


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7. A legend or key to the symbols used to identify objects or points of interest on the sketch.

B. Considerations Involved in Crime Scene Sketching

The measurements shown on the sketch should be as accurate as possible and they need to be made and recorded uniformly. Steel tapes are the best means of taking measurements. It is difficult to explain an erroneous measurement on a drawing, and can introduce doubt in the minds of others as to the competence of the entire search of the crime scene.

1. Rough and Smooth Sketches

Rough Sketch

A rough sketch is drawn free-hand by the crime scene specialist at the scene of the crime. Changes should not be made to it after the specialist has left the scene. This sketch will not normally be drawn to scale, but will indicate accurate distances, dimensions, and relative proportions.

Smooth Sketch

A smooth sketch is one that is finished and is frequently drawn to scale from the information provided in the rough sketch. If a sketch is drawn to scale, the numbers concerning the distances can be eliminated. However, if the sketch is not drawn to scale, the distances need to be shown.

�� Lesson Objective #7.3 Identify three (3) methods used in sketching a crime scene.

Methods of Sketching

A. Coordinate Method

The coordinate method measures the distance of an object from two fixed points. One form of this method uses a baseline which is drawn between two known points. The baseline could be a wall, or drawn as a mathematical center of a room, the exact dimensions of which are known.


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The measurements of a given object are then taken from left to right along the baseline, to a point at right angles to the object which is to be plotted. The distance will be indicated in the legend with a number in parentheses following the name of the object.

B. Triangulation Method

The triangulation method is useful in an outdoor situation where there are no easily identifiable edges of roads or fields to use as reference points. Two or more reference points are located and should be widely separated if possible. The item of interest is located by measuring along a straight line from the reference points.

C. Cross-Projection Method

The cross-projection method is useful when the items or locations of interest are on or in the wall surfaces as well as elsewhere in an enclosed space. The walls, windows, and doors in a cross-projection sketch are drawn as though the walls had been folded flat on the floor. Then a sketch is drawn of the measurements from a given point on the floor to the wall.

�� Lesson Objective #7.4 Identify at least two (2) reasons why photographing the crime scene is important.

IV. Photographing the Crime Scene

In certain types of crime, particularly those involving physical violence, the crime scene and the location of all relevant objects within it are of vital importance in establishing points of proof.


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Importance of Crime Scene Photography

1. Permanent record

A permanent record of the crime scene is considered indispensable to a successful presentation of the case in court. A crime scene that is altered through carelessness and haste can never be restored to its exact original condition.

2. Significance of certain aspects of the crime scene

Also, in the initial stages of an investigation, the significance of certain aspects of the crime scene may not be evident, although later they may vitally affect the issues in the case. The first step in the investigation of any crime is to photograph all aspects of the crime scene completely and accurately before any of the objects of evidence are removed or otherwise disturbed. Photographs should also be taken after a body or bodies have been removed. It is always better to take too many photographs than too few.

3. Reconstruction of crime scene

A study of photographs can also assist the trained investigator or crime scene specialist in reconstructing the crime scene and developing conclusions about how the crime occurred. In addition, the photographs will make the job of the prosecutor much easier when a case is presented in a court room. When necessary, photographs can be coordinated with crime scene sketches or drawings that are made to scale.

B. Procedures for Photographing the Crime Scene

The goal is to record useful information in a series of photographs which will enable the viewer to understand where and how the crime was committed. The term “crime scene” refers to not only to the immediate locality in which the crime took place, but also to adjacent areas where important acts took place immediately before or after the crime was committed.

Photographs of the broad area of the crime scene should be supplemented by closer shots of sections containing important detail. Each area or object should be photographed so that it can be located readily in the overall


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pictures, which will enable the viewer to gain a clear concept of its position with reference to other objects at the scene.

C. Sequential Photographs of the Crime Scene

Each crime has individual features that should be photographed. Keep in mind the nature of the offense and try to show those features that establish the elements of the offense. Photographs should be taken of:

1. Views of the exterior of the building/vehicle, with relations to other buildings/vehicles, roads, streets, etc.

2. Points of entry, outside and inside.

3. Point of exit, inside and outside.

4. Condition(s) of the crime scene.

5. Area from which valuable articles were removed.

6. Articles left at the scene.

7. Trace evidence, such as hairs, fibers, and cigarette butts.

8. Toolmarks and impressions of shoes or tire tracks.

9. Fingerprints and footprints, as well as articles on which these prints may be found.

D. Range Photographs

An important aspect of consideration regarding the various “range” photographs is the general point-of-view established by the camera locations. These locations will enable the viewer of the pictures to orient the crime scene in a logical manner. The three types of “range” photographs are:

1. Long-range

Long-range photos of the overall scene fundamentally are taken to portray the areas as if a person viewing the scene is viewing the scene is


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seeing it from the standing position. To obtain this result, the photographer takes the photograph with the camera at eye level.

2. Mid-range

Mid-range photos are taken in a manner which portrays the scene from approximately ten to twenty feet of distance from the subject matter. In order that the viewer be permitted to associate the crime scene with separate areas of the scene photographed, these areas should contain sufficient detail to permit the viewer this association.

3. Close-up range

Close-up range photos are normally taken approximately five feet or less from the subject matter. The attention of close-up photography is directed to objects which could not effectively be seen in the long-range or mid-range photos.

E. Markings in the Field of View

Measuring devices such as rulers, yardsticks, and tape measures should be used to show the relative size of, and distances between objects, or the degree of magnification of the enlargement. The markers should be placed beside the object in a manner that will not obscure any important piece of the evidence. In document and small-object photographs, a six inch ruler placed at the bottom or just below the item of evidence will enable the photographer to determine the degree of enlargement quickly and also show the relative size of objects in the photographic exhibit.

Many times, courts object to the use of rulers and marking devices that appear in photographs of a crime scene. Therefore, photographs should be taken in two ways: first without the markers and then with them.

F. Basic Requirements of a Photograph Admitted as Evidence in Court


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No matter how extensive the photographic efforts are at the crime scene, photographs must stand the test of legal admissibility. The general standards used to review the credibility of the photographs are:

1. Accurate representations

2. Free of distortion

3. Material and relevant

4. Unbiased

G. Camera Motion

Camera motion can be the cause of a lack of sharpness. There are two prime causes of camera motion. The first cause is vibration and it is usually caused by body movement including the beating of the heart. The second cause of camera motion is actual camera movement caused by the improperly holding of the camera. The basic technique for holding the 35mm camera is:

1. Grasp the camera with the right hand placing the index finger under the shutter release, thumb under the film advance and the remaining three fingers against the front of the camera.

2. The heel of the camera should be placed in the palm of the left hand.

3. The placement of the rest of the body while taking the photograph is as important as holding the camera.

The investigator’s arms should be resting against the body with the legs far enough apart to be a steady base. When taking a photograph in a kneeling position, do not rest the elbow on the knee as the bone-to-bone contact is unsteady and will be reflected in the photograph.

H. Categorizing Photo Evidence

The investigator must make a written record of what is recorded on film. The first frame of the crime scene photographs should be a photograph of a


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chalk slate or a piece of paper, preferably the size of a piece of notebook paper, that contains information identifying the case. This information should include the name of the photographer, the name of the victim, the address, date, case number, and time. By including this information on the roll of film, the chances of the film being misplaced or misdirected by the photo lab will be lessened. The following information should also be recorded in the crime scene specialist’s notes:

1. Department name, location, date & time

2. Type of incident & objects photographed

3. Type of film used and number of exposures

4. Type of camera used

5. Identity of the crime scene specialist

6. Names of victims & witnesses

7. Chain of Custody

The chain-of-custody of the photographs must be maintained. The film should be removed from the camera and taken directly to processing unless some secure facility is available for overnight storage. If this does not occur, the judge or jury may disregard this most important evidence under the theory that the film may have been tampered with.

�� Lesson Objective #7.5 Identify the importance of film speed and film type.

V. Using the Camera

While almost any camera can be adapted to the needs of a crime scene specialist, the most popular is a 35mm SLR (single-lens-reflex camera), with through-the-lens viewing, built-in metering and interchangeable lenses. The availability of fine-grained and ultra-sharp roll films allows the 35mm format to be usable for a wide variety of needs.

A. Film Speed

Taking a good picture is not always easy and requires some skill and the right type of film. The “speed” of the film is related to the amount of light sensitivity. The higher the ASA rating, the less light is needed to record an image on it. Film “speed” is also a factor in determining the correct exposure. The film speed controller is usually located on the top of the camera or on the top left side. An ASA of between 64 and 160 is normal,


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but higher than 200 is considered fast. Conversely, between 25 and 32 is considered slow.

1. Slow films

Slow films are best for scenes where the light is bright and they often have a brighter detail and give the sharpest image.

2. Fast films

Fast films are used for situations where you couldn’t use slow film because the light is low. The quality, however, is not as good as the slower films speeds. In fact, with very low lighting, the background may disappear altogether.

B. Film Type

Some films, including slide films, are made specifically for shooting in will-lighted situations like daytime. Others are made for artificial light, incandescent lighting and stage lighting. High speed transparency film allows the operator to shoot a roll of film at a speed higher than recommended because the processing of the film can make up for the difference in light. The photographs will not be as clear or precise, but it can be useful where additional speed is needed.

�� Lesson Objective #7.6. Name the two (2) adjustments on a camera that control the amount of light that reaches the film.

VI. Exposure Controls

The crime scene specialist must always remember that a camera makes adjustments to light much like the human eye. You might say that the eye has a built-in light meter. That same light meter is imperative for getting usable shots with a camera. A “light meter” will tell the photographer what camera settings will give the best results. Two adjustments on the camera can control


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the amount of light that reaches the film. They are called the “Shutter Speed Control” and the “Lens Opening”.

A. Shutter Speed Control

The “Shutter Speed Control” determines the length of time that the film is exposed to light. The numbers found on the control correspond to fractions of a second.

B. Lens Opening

The size of the “Lens Opening” on your camera is the other factor that determines the amount of light that reaches the film. The indicator on the camera for the degree of light passing through the camera lens is called the “f”number. The smaller the “f” number the smaller the opening and vice-versa. Much like fast films and slow films, there are fast and slow lenses. A fast lens, for instance, is one that transmits a lot of light. The user should be cautious, however, since fast lenses do not produce the sharpest images.

C. Depth of Field

1. Definition

“Depth of Field” is usually misunderstood and thought to be the sharpness in front and in back of the subject of the photograph. The term is really used, however, to describe the distance that the crash investigator can move away from the subject and still maintain a sharp image. Depth is the area in front and in back of the photograph.

2. How to get depth

a. Use a small lens


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To get depth, the crime scene specialist will use a small lens with a large “f” number. Understanding this concept will control the sharpness of every photograph.

b. Change in depth

Increasing depth can be accomplished by moving further away from the subject of the photograph, but this often distorts the photograph by changing the size of the subject’s image. A more plausible way to change depth is to set the aperture (lens opening) to a higher number. The shutter speed, however, must also be adjusted because of the corresponding light restriction that will naturally occur when going to a higher “f” number. When depth is an important element of the photograph, use the smallest aperture possible to keep the picture sharp.

c. Moving subject

When you are photographing a moving subject, a fast shutter speed will be needed to stop the action.

Note: Keep in mind that moving away from the subject of the photograph will give a greater depth. Also remember that telephoto lenses will have considerably less depth than normal lenses and you can’t move back to achieve depth.

D. Focus

The sharpness or focus of a photograph will make a big difference in a court of law. If the jury can see exactly what has taken place through a series of photographs that are clear and concise, the evidence will be much easier to understand.

1. Sharp images

Getting sharp images may be difficult when close-up photography is required. Although the “film speed” and the “depth of field” is not critical in a close-up photograph, the crime scene specialist must always find a focal point that can serve as a visual reference point and be understood by a judge or jury. In other words, the photographer must decide how much meaning he/she would lose for any particular focal choice.

2. Tripod


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Since the depth is so shallow, the crime scene specialist must concentrate on the most important part of the photograph. The tripod will be best used for a close-up photograph as described.

Note: Remember that the sharp area of the photograph extends about one-third in front and two-thirds beyond the subject of the photograph. Also remember that the lens used has a significant effect on the way that the photograph will look when processed.

3. Type of lens

Sometimes the crime scene specialist may want to highlight a particular part of the photograph. To do so may require a different lens. Wide-angle lenses, for instance, make objects look smaller and distances between look greater. Conversely, zoom lenses can be adjusted to acquire a close-up photograph that can be taken from some distance.

E. Bracketing

Bracketing is akin to having an insurance policy. The crime scene specialist will take a shot that he/she feels is the best and then will take several more shots at different exposures just to make sure he/she has what he needs.

�� Lesson Objective #7.7 List the six (6) steps used to load film into a 35 mm camera and the three (3) steps used to unload film from a 35 mm camera.

VII. Loading & Unloading the 35mm

A. Loading Film

To load the film into a 35mm camera:

Open the back of the camera by lifting the film rewind knob and pulling out the back.

With the rewind knob up, fit the film canister into the chamber on the left side under the rewind knob.

Push the stem of the rewind knob back down and lock the canister into place.

Pull the tail of the film gently out of the canister and insert it into the take-up spool.


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Turn the rewind knob slightly to make sure that the film is snug against the sprockets and advance the film once.

Close the camera and advance the film twice more.

B. Unloading Film

To unload the film from a 35mm camera:

Release the take-up spool by pushing the film rewind button on the bottom of the camera.

Pull the rewind lever out and turn it slowly until it is released from the take-up spool.

Turn the lever a few more times and then open the back of the camera and remove canister.

C. Care & Handling of the Camera & Film

The investigating officer should take care of the camera between uses by keeping it out of direct sunlight and away from heat sources. The camera should never be exposed to direct sunlight or to heat from being placed in glove compartments or trunks of vehicles in the hot weather. The investigator should also keep the film in an insulated chest or wrapped in white reflective cloth. Exposed film should be maintained in a refrigerator or processed immediately. In cold weather, the camera should be protected by keeping it under your jacket as the film may become brittle and tear or


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break. Salt water may also damage your camera and film so make sure the camera is fully protected.

Summary

In this lesson, we learned that one of the most important things a crime scene specialist is responsible for is the accurate documentation of a crime scene. This documentation consists of copious notes, rough and smooth sketches of the crime scene, along with ample photographs. All of these must accurately depict the crime scene and be readily available for trial purposes months or even years after the crime. Additionally, all of the methods of documentation must be clear and concise enough able to be understood by others, to include investigators, prosecutors, and members of the jury. Great care must be taken by the crime scene specialist to ensure that documentation of a crime scene is thorough and error free.


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NOTES


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Glossary of Camera Nomenclature

Aperture

The circular adjustable lens opening through which light enters the camera. The lens can be adjusted to restrict the amount of light passing through.

Filter

A plastic or optical quality glass that is used in front of the lens to increase contrast or reduce glare. The glass is usually tinted or colored to absorb light.

Flash

The flash is used to provide artificial lighting in otherwise darkened pictures. The ordinary flash bulb has been replace by the electronic flash in recent years.

Light Meter

A device, also known as exposure meter, that measures light intensity in relation to film speed.

Shutter

A control on the camera that is set for a timed light interval that allows the appropriate quantity of light to pass through the lens.

Standard Lens

The 50mm lens sold with most 35mm cameras is known as a standard lens and most closely fits the perspective of the human eye.

Telephoto Lens

A long compact focus lens that yields a larger image than normal.

Tripod

A three-legged support for a camera that steadies the camera and ultimately creates a better photographic image.

Wide-Angle Lens

A lens with a wider than usual angle of coverage.

Zoom Lens

Using a zoom lens can give the photographer a different angle of view including different focal lengths over a certain range.

Photography Terminology


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The following definitions reflect many of the terms used to describe the process of photographing. These definitions will provide a foundation upon which to describe techniques commonly used to obtain the sharpest, clearest and most valuable photographs for court purposes.

ASA

The measurement for rating the speed or light sensitivity of the film. The abbreviation stands for the American Standards Association. The higher the arithmetical designation, the more sensitive to light the film will be.

Balance

A term used to describe how the subject matter is arranged in a single frame.

Bracketing

Taking a subject photograph using what is perceived to be the best lighting, film, etc., then taking several more photographs at different exposures to make sure that a productive photograph exists.

Depth of Field

The area in front and in back of the focal point or object of the photograph. The smaller the lens aperture, the greater the subjective impression.

Distortion

Changes in the photograph normally caused by a particular lens and different from what would be seen on a standard lens. Distortion deforms the shape of an image.

Electronic Flash

Light produced by passing an electric charge at high voltage through a gas in a sealed transparent container.

Exposure

The effect of light striking the film can cause distortions after chemical processing (too little or too much). Overexposure can be the result of to much light and underexposure can be the result of inadequate light.

Film Speed

The numeric measure of the film’s sensitivity to light is known as “speed”. The higher the numerical rating, the “faster” the speed.


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Focus

An adjustment used to bring the main subject into to sharp or clear focus.

Framing

Getting the picture you want within the boundaries of the frame being shot.

Overexposure

Excess light hitting the film will cause film distortion and overexposure.

Panning

Tracking a moving subject with a camera and trying to keep the subject on the photograph centered in the frame.

Viewpoint

Finding the correct camera position in order to capture the crash scene in the most realistic way.


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NOTES


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Practical Exercise #7-1: Photographing and Sketching the Crime Scene

Performance Objective

The objective of this exercise is to provide the participants with the opportunity to practice note taking, photography and the drawing of a rough and smooth sketch of a fictitious crime scene.

Duration of Exercise

Six (6) hours

Instructions

The class will be divided into four (4) groups. Each group will be provided with a fictitious crime scene that has been staged either indoors or outdoors. The participants will be taken to these staged crime scenes and provided with a brief scenario regarding the crime that has allegedly occurred there and provided with a departmental case number and the name of the victim. They will be told to stop and observe the crime scene and take copious notes describing what they see and what obvious items of evidence exist.

After the note taking is completed, the participants will be allowed to methodically take the necessary crime scene photographs in order to properly document the crime scene, before measurements and notes are taken to create a rough crime scene sketch. The participants will need to prepare a smooth crime scene sketch after they have completed their work at the crime scene.

Each participant will be required to take his/her own photographs and create individual photo logs, detailing each photographs taken and what they depict.

Once the photography has been completed, participants will be allowed to work in pairs to take their measurements. Each participant will be required to create his/her own sketches.

60

NOTES

ON

FORENSIC PHOTOGRAPHY

Prepared by:

HERMOGENES P. MALAGAMBA

gemini criminology online review and training center p e n e t e e a p · 2016. 5. 26. · icitap...

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