Taking Better Pictures IIGetting more from your camera

©2013 Domenico Pino

Dom@ChannelOne.US

PinoDomenicoPhoto.com

This class is intended for: • SLR and DSLR users. • Users of other cameras that allow manual control of settings• Students of photography who want to understand how cameras work

Getting more from your camera

• Exposure – shutter speed & aperture (f/stop)• Exposure Value – how much light• Exposure Modes – preferred camera settings• Film/Sensor speed – ISO/ASA• Metering Modes – matrix, center weighted, spot• Focusing modes - closest, center, averaged• All about Lenses – prime, zoom, wide, telephoto• Depth of Field – what’s in focus• White Balance – reddish, bluish, just right• Filters – UV, ND, Polarized, and more

Aperture

Each f/stop is ½ area of the previous one

Diameter ÷ √2 =1.414ea step

Exposure ValueBasic Terms

• Exposure is a function of – Aperture (f/stop)...larger to smaller opening as follows:

• 1.0, 1.4, 2.0, 2.8, 4.0, 5.6, 8.0, 11, 16, 22, 32, 44, 64, 90• Each step is ½ the area of the previous = ½ amt of light

– Shutter Speed (usually in fractions of a second)• 1/2000th 1/1000th 1/500th 1/240th 1/120th 1/60th 1/30th 1/15th 1/8th

• Each step is open twice as long = 2x amt of light entering

– Film (or Sensor) Speed (ASA/ISO) higher = more sensitive

• 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600• Each step increase is 2x as sensitive = requires ½ exposure

Aperturewhat the f/stop numbers really mean

f

Focal plane of

film or sensor

IRIS

d

f = distance from focal plane to apertured = diameter of aperture (iris)

d (iris diameter) is expressed as fraction of f

f /1.0 means d = f f /1.4 means d = f/1.4 (1/2 the area of d = f)f /2.0 means d = f/2 (1/4 the area of d = f)f /2.8 means aperture is 1/8 area of d = ff /4.0 means aperture is 1/16 area of d = f

Each successive f /stop is ½ the area of previous f /stop which means it lets in half as much light.

Exposure ValueBasic Terms ..2

• Exposure ValueValue• Corresponds to the amount of light on the subject/scene

and to the matching settings of ISO, speed, and aperture• Each doubling or halving of the amount of light = ±1 EV • (1/60th, f/8.0) (1/120th, f/5.6) (1/250th, f/4.0) have same EV

• If the Sensor/Film sensitivity (iso) is doubled... • Then the same scene EV can be captured through either

twice the speed (faster) or half the aperture (higher f/Number)• Example: 1/60th, f/8 @100 iso has same EV as any of following:

►1/120th, f/8 @200 iso (½ time, at 2X sensitivity)►1/60th, f/11 @200 iso (½ aperture, at 2X sensitivity)►1/120th, f/11@400 iso (½ time & ½ aperture, at 4X sensitivity)►1/120th, f/16 @800 iso (½ time & ¼ aperture, at 8X sensitivity)

Take the time to

understand what this

means

Take the time to

understand what this

means

Shutter speed 1/1000th sec (fast), Aperture f/2.8 (wide)

Shutter speed 1/60th sec (slow), Aperture f/11 (narrow)

Shutter speed vs. f/stop for given EV @ ISO=100

Exposure ValueHow to decide what to limit (f/stop, shutter, or iso)?

• Shutter speed• Faster shutter speed is required for moving subject• Slow shutter speed produces blur (fireworks)

• Aperture• Smaller aperture (higher f/) = sharp focus, large DOF• My old Polaroid @f/90 would focus 3½ ft to infinity• f/1.4 to 2.8 produces soft backgrounds: “Bokeh”

• Sensor/Film speed (sensitivity to light)• Hi ISO allows shooting moving objects in less light• ISO > 400 starts to introduce grain (aka “noise”)

1/15th sec f/2.8 @1600iso - some granularity

Exposure ValueHow to decide what to limit (f/stop, shutter, or iso)? ..2

• Most of the time, – the subject will determine the shutter speed and

you will make a trade off between higher f/stop for sharpness, and lower ISO to reduce grain

• Nightscapes (and fireworks) – are best shot with tripod so a small aperture (hi f/)

and low ISO can be used with a long exposure.

• A larger aperture (f/2.8 to f/1.4) – can be used to diffuse the background into a soft

focus

Small aperture f/11 prevents hot spot overexposure at ½ sec to 1 secTripod mandatory for exposures longer than 1/15th sec

Exposure Modes part 1

• Automatic – Camera makes all judgment• You can set ISO in following modes only

– (P)rogrammed • Increasing shutter speed will auto lower f/stop

– (A)perture Priority (depth of field is critical)• Camera selects shutter speed for correct exposure

– (S)hutter Priority (shutter speed critical)• Camera selects aperture for correct exposure

– (M)anual• You control both shutter and aperture separately• Very common when external flash is used for extra lighting

e.g. f/4.0, 1/120th, 400iso, fill flash – indoor gatherings

Viewfinder Display

[ ]

[ ]

FocusArea

Brackets

Speed f/stop

Light

Meter

+/-

Exposure

Comp

Make Sure You Understand These 4

It’s important you learn to use the Viewfinder Display to control your settings while looking at your subject and NOT on the LCD display on the back of the camera!!

+/- EV Compensation

Nikon Controls Blue Arrows

show location of Exposure Compensation

and PSA&M modes.

Hold down button while

scrolling Thumbwheel

(dial)

Auto plusPSA&Mmodes

Vary/scrollThumbwheel.

Read on LCD orin Viewfinder.

ISO

Hold down ISO button &

scroll dial

Nikon Controlsfor ISO are on back panel or

found on menu

Exercise 1Tradeoff between time & f/stop

• Set camera to P (programmed) mode.

• Aim at a subject

• Use thumbwheel (dial) to vary settings

• Observe, in the viewfinder, how shutter speed and aperture tend to shift (one increases, other decreases) as you scroll thumbwheel back and forth.

Exercise 2Tradeoff between ISO, shutter speed, and aperture

• Set camera to P (programmed) mode.

• Note aperture at t=1/60th sec

• Change ISO, re-examine same subject, and note change in aperture

• Observe that when ISO is increased, a smaller aperture (higher f/number) is selected for t=1/60th, or that same aperture will have selected a faster shutter speed

Exercise 3.1Shutter Priority

• Set Mode to S (Shutter Priority).• Pick a subject – Look in Viewfinder Display

– While paying attention to shutter speed indicator (see diagram on earlier slide) use the scroll wheel to set the speed to 1/60th sec.

– Point at differently illuminated subjects and note how shutter speed remains fixed (only the aperture {f/stop} will change)

• If light is insufficient “LO” will display for f/stop• Too much light will display “HI” for f/stop

– This means it’s beyond the lo/hi capacity of the lens

• Use this mode when Motion is critical

Exercise 3.2Aperture Priority

• Set Mode to A (Aperture Priority).• Pick a subject – Look in Viewfinder Display

– While paying attention to aperture {f/#} indicator (see diagram on earlier slide) use the scroll wheel to set the aperture to f/5.6

– Point at differently illuminated subjects and note how aperture remains fixed (only the speed {time} will change)

• If light is insufficient you may need a tripod• Too much light {bright day at high iso} may display an error

– This means it’s beyond the capacity of the shutter (too fast)

• Use this mode when Depth of Field is critical

Exposure Modes part 2

• Exposure Bias (compensation) or “fool the sensor”– Only in Programmed and Priority (S,A) Modes

• Used to tell camera to lighten or darken the image• Can usually extend ± 2 or 3 EV stops• Usually calibrated in ½ or 1/3 EV increments

– Bride with white dress • will tell camera sensor there is much light. You’ll need to

Increase bias by +1EV to avoid under-exposure

– Subject in bright background (except in spot metering)

• will silhouette faces. Increase bias +1EV or use flash

– Men in dark suits in poorly lit background• Camera sees little light, will overexpose faces. Use -1EV• Afro Americans may have correct exposure. Use NO bias

Electronic Analog Exposure Display

• In Manual Mode– Use this display as a simple light meter– Changes as you alter speed, f/stop, and ISO– Changes as you alter the scene or metering– There is no EV compensation in manual mode (on most cameras)

• In (P)rogrammed and Priority (S,A) Modes– Camera tries to make setting for balanced exposure– Display will show [......|......] unless camera cannot make the correct

setting because the scene exceeds [Hi] or [Lo] limits of camera– If EV compensation is used, it will show the amount [over | under] – Display is Blank [......|......] when 0 EV comp is used because

camera is selecting what it thinks is the balanced exposure.

[+........|!!!!...-][+........|........-][+...!!!!|........-]over exposed balanced under exposed

Use this light meter built into your camera

Use this light meter built into your camera

Exercise ...4Setting Exposure Compensation

• Set Camera to Programmed (P) or Shutter priority (S), or Aperture priority (A) mode– Locate button to adjust EV comp

• usually around main dial – often on right side

– While holding down button to adjust EV comp:• Vary the amount of compensation via the main dial (usually on

back of camera)• Observe changes to [+/-] indicator and LCD

– Analog Exposure Display will show the amount of EV compensation in ½ or 1/3 EV steps depending on menu preference settings, eg. (-1.0 -0.7 -0.3 0.0 +0.3 +0.7 +1.0)

– LCD (top of camera) shows +/- decimal EV values

– On some cameras, this may display on the back LCD panel

Metering

• Metering is how the camera sensor measures subject illumination– Matrix

• Measure the light in the scene as a whole

– Center-Weighted• Measure the light in the scene as a whole but

consider the light on the subject in focus with greater importance

– Spot• Measure the light on the subject in focus only

Metering...2

• How to select the right Metering Mode (P,S,A)– Select metering via the menu– Matrix (default)

• When all parts of the scene are equally important• Set exposure based on composition, shading, distance & color• Film has a better dynamic range than digital sensors

– Center-Weighted• Reads entire frame but assigns prioritizes center (for portraits)• Use Flash to minimize silhouetting in daytime

– Spot• In daytime, without a flash, this will “blow-out” the background,

to minimize silhouetting the subject• Measures only the active focus area

Metering...3

• How to Override Metering– Use +/- EV Compensation in PS&A modes– In Manual mode, you have complete override

(EV Compensation does not apply)– The Electronic Analog Exposure Display

• EV Comp will be shown in display (PS&A modes)– i.e., changing EV Comp will alter the display– +/- 0 EV will show a blank display

• Will function in all modes according to the metering method selected.

Focusing

• Focusing Modes• Auto

– Camera selects mode according to motion detection

• Single Servo– Focus locks when release is half pressed– Use with stationary subjects

• Continuous Servo – Focuses continuously when release is half-pressed– Use with moving subjects

Focusing...2

• Focusing Area Modes• Closest Subject = usually the closest object to you

– Default for Auto, Portrait, and Macro (close up) modes

• Single Area = what you are pointing at– You select focus area manually (hi/low/left/right/center)

• Multiple/Dynamic Area = what is around what you are pointing at

– You can set focus area manually (up/low/left/right/center)– Camera uses info from multiple areas– Use for erratically moving subjects

Lenses

• Focal length– Long focal lengths are telephoto (70mm+)– Short focal length are wide angle (35mm -)– Prime: fixed focal length, very sharp (50mm±)– Zoom : variable focal length (e.g.18-200mm)– The longer the lens, the smaller the max

aperture or the much greater cost• A fast lens is usually a telephoto with a wider aperture (f/2.8)

because it allows a fast shutter speed ($$)

Lenses ..2• Rule of Thumb

• To prevent vibration (blur), the shutter speed should be 1 ÷ focal length (secs)

• For 300mm telephoto, use 1/300th second minimum, for example

• Crop Factor – DSLR’s• FX cameras are full frame (same as 35mm film)• DX cameras have a smaller sensor.

– Focal length is multiplied by approx 1.5x– A 70-300 mm lens is really 105-450mm lens to camera– A 50mm prime lens is really a 75mm prime lens– Images will look larger with same lens– FX lenses can be used on DX cameras – not vice versa

Lenses .3

• Lenses for my Nikon D50 (DX* format DSLR) * on my camera, crop factor multiplies focal length by 1.5x

– Zoom (by focal length, max Aperture (min f/)• 28-80mm f/3.3-5.6 – good gen purpose

(Effectively 42-120mm) max Aperture decreases with zoom

• 18-50mm f/2.8 – better (effectively 24-75mm)

Retains max aperture (min f/) at all focal lengths

• 70-300mm f/4-5.6 (effectively 105-450mm)

– Prime• 50mm f/1.4 (effectively 75 mm)

Very nice portrait lens. Lovely bokeh. Good in v.low light.

Depth of Field

• Depth of field• How much “depth” is in focus

before/after subject• “Shallow” – only subject plane is in

focus = Bokeh• Small aperture (hi f/) = Longer

Depth of Field• Telephoto lenses compress

distance and seem shallow DOF• The closer you shoot, the more

critical/shallower the DOF

Shallow Depth of Field

Bokeh

Telephoto lenses appear to have shallower DOFWide Angle Telephoto

Prime Lens marking showing greater DOF at smaller (hi f/22) ApertureCentered at 1.5 meters (5ft) DOF is from 1.2-3m (4-10ft)Centered around 3m, DOF would be from 3m-Inf (10ft to Inf) - example of how DOF increases with distance (same focal length)

Focused on 2nd setting for greater DOF

White Balance• Auto

• camera averages all light

• Outdoor (or Flash)• If you use this inside

pictures will look reddish

• Indoor (Tungsten)• If used outdoor, pictures

will look bluish

• Fluorescent• Use this to avoid that

greenish look when under mercury or fluorescent lamps and no flash is used

Filters

• UV (haze) – adds some clarity, protects lens.• Polarized – minimize reflections (store windows)• NDx (Neutral Density) – reduces “x” f/stops in bright settings where

larger aperture is needed for DOF or shooting object in front of Sun

Less Used:• Colored – for B&W to add color based contrast• Graduated (to clear) - accent sky (blue) or sand (yellow)• Spot – focus in center, diffuse surrounding• Diffusion – softens focus, removes wrinkles• Diffraction – produce spectral aura around light sources• Star (4-6-8 pt) break up spotlights, sparkles on water

Polarized filter reduced reelectionsPolarized (left)

+grad ND

(below right)

UV and Skylight Filters

• UV is invisible to the eye but not to some sensors• Skylight filter is pink - cuts blue, adds warmth

Filtered

Filtered Unfiltered

Diffusion Filter

Diffraction filter

Star Filter