Panoramas and photo stitching

A “Mastering the Art of Photography” Topic

Developed by Evelyn Durmaz

August 31, 2013

Picasa 3.9 software is used in this presentation.

Cary Photographic Artists

What is a panoramic photo?

• An image showing a field of view

approximating, or greater than, that of the

human eye – about 160° by 75° – may be

termed “panoramic”

• Essentially any image that exceeds a 2:1 ratio

(height to length or vice versa) is considered a panoramic

Two ways to produce a panoramic photo

1. Cropping

2. Stitching We will look at examples of these using the free software package Picasa and Windows Live Photo Gallery software, which comes with Windows 7. Then we’ll check out some related, more advanced topics: • Focus stacking • HDR, or high dynamic range photography • Astronomy photography • Removing people or items from a scene by stacking

multiple photos

To create a panorama: load photos to your software

Here we are using Windows Live Photo Gallery. You may be able to use software that came with your camera.

Run the stitching program

Select the photos for the panorama, then click on the Panorama icon in the Create tab. Wait a couple minutes for the stitching software to work.

Voila! You have created your panorama.

Straighten the photo in the Fine Tune menu

In the Edit tab, click on Fine Tune. Use the slider to straighten the image.

Select the crop icon next

Adjust the crop and click on crop again to apply

Adjustments??

But wait! There are a couple problems here……

The porch post was cut off (“ghosting”). The sidewalk is curved.

Maybe we overreached- start over

Twelve photos are selected, avoiding the post.

Potential problems

This is still not perfect. Be careful with pasting multiple photos with slightly different perspectives.

Here we’ll stitch three photos together

This is more successful.

Only three photos were used, and all were taken from the same perspective.

Adjusted panoramic

This is the image after cropping and brightening.

Simple rules

• A zoomed-in lens has a wider angle of view.

• The wider the angle, the fewer the shots needed for a panoramic.

• If the lens is zoomed out, it has a shorter angle of view and distances are compressed.

• Maintain a single perspective and avoid focus and exposure changes in the series for a panoramic.

Tips and tricks

• Keep the camera level (a tripod is helpful)

• Start from left and pan right

• Overlap images at least 20%

• Practice shooting the series

• Don’t hesitate to start over

Advanced tips

• Lock exposure & ISO (in MANUAL MODE)

• Lock focus and aperture, if possible

• Use a panoramic head/Jig

• Pay attention to moving objects

• Watch for extremes of light/shadow

• Shoot in portrait orientation for maximum height

An example of using cropping to create a panoramic image.

The crop tool is used in Picasa editing software. The manual setting is used to size the cropped image.

Here is the cropped panoramic from a single photo.

Pros and Cons of stitching and cropping

Stitching

• Pro: The final image can have more resolution than each of the contributing images.

• Con: Problems can occur with exposure and perspective (e.g. the sky changes color, ghosting).

Cropping

• Pro: No exposure or perspective problems.

• Con: Less resolution in the final image, since some information in the original image was discarded. Limited by the view in one shot.

Advanced topics

These are dedicated film cameras for taking panoramic photos.

Specialized gizmos to help

http://www.panoramicessentials.com/panoramic-tripod-heads.html

• Tripod heads can help you rotate the camera in increments.

• Motorized heads can automate the process.

Software

Focus

“Focus” is comprised of two components:

• Focus Point – where the camera is focused.

• Depth of Field (DOF) – the distance in front of

and beyond the focus point that appears to

have no visible distortion.

Hyperfocal distance

A focal point at which everything half way from the camera up to the focal point is in focus AND everything beyond the focal point (to infinity) is in focus. Use this point for manual focusing in landscape panoramas.

http://www.dofmaster.com/hyperfocal.html

The problem with our first panorama

https://en.wikipedia.org/wiki/Parallax

More topics on photo stacking

HDR photography: “high dynamic range” • Our eyes make adjustments for a wide range of light to

dark in everything we see. –But our cameras are limited to the range of light that can be captured by the film or camera CCD.

• Several photos are taken of the same scene, with different exposure settings, but the same focus

• Instead of combining into a panorama, the digital images are stacked on top of each other, and the HDR software chooses the parts of each image that are properly exposed, and combines them into one image.

HDR photography- photo stitching technique

• HDR is the technique of merging 2 or more bracketed shots into single image.

• Allows a greater range of color and exposure than a single shot could capture.

• VERY useful for indoor shots!

Reduce need for lighting

Can compensate for overexposed windows

• VERY easy to go overboard with color saturation.

• Many software solutions including Photoshop.

• Best is “Photomatix” (www.hdrsoft.com)

Three photos used for HDR

HDR from 3 images in Photoshop

Focus stacking

Two types:

1- Z focus stacking combines macro images

• Macro images have a very narrow depth of field

• Stacking macro images with different focus points produces a single image with increased depth of field

• Astronomy also uses stacked images to extend the depth of field and remove noise.

2- Stacking to remove people from a scene

Multiple images are taken and then all the people can be removed, leaving just the scene

Z-stacking

https://en.wikipedia.org/wiki/Focus_stacking

Remove people from a scene

Two photos were stacked and the people were removed using Photoshop Elements 7.0 (Photomerge Scene cleaner).

http://www.peachpit.com/articles/article.aspx?p=1245326&seqNum=3

Night sky imaging

http://www.msb-astroart.com/

Stars are dim, and they move across the sky. Many software packages are available to help capture and correct sky images. http://www.astropix.com/HTML/I_ASTROP/SOFTWARE.HTM

Things to try • As you go about your day, look around, and think

about how you could capture panoramas of what you see. Increasing your field of view can be enlightening.

• Try to make both stitched and cropped panoramas. • Try photo stacking techniques. • In the days of film cameras, people would take

double exposures (expose the same piece of film twice by not winding or rewinding. If you have a film camera that will do this, it can be fun and you will be surprised. Or try it digitally for fun.

Resources 1- The help screens of Picasa or other photo editing software.

2- http://www.thefullwiki.org/Panoramic_photography

3- More detailed information on panoramas:

http://www.photographycorner.com/articles/technique/the-secrets-to-panoramic-photography

4- CPA presentations (http://caryphotographicartists.org/education.html):

• Computer Editing

• Understanding Your Histogram

• Photography Fundamentals

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