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Photographic Mathematics Documents

We have researched the principles of digital and film photography for several years. The result is a series of four white papers detailing physics and mathematics relevant to current digital practices. The approach to the topic is largely original with us and we have not seen similar treatments elsewhere, either in print or on the web. In particular we believe our fourth paper on Complete Color Integrity is unique and presents an important element of digital photography that has been completely missing. These papers are part of the basis for our Phototips series available on this website.

The four documents are available in PDF format. Click on the document name to view or download, and after viewing, use the "Back" button to return to this page.

1. CFS-242 Film Gamma Versus Video Gamma PDF (175KB PDF).
2. CFS-243 Maintaining Color Integrity in Digital Photography (297KB PDF).
3. CFS-244 Negative to Positive (291KB PDF).
4. CFS-276 Complete Color Integrity (1.25 MB PDF).

The first document develops an understanding for "gamma," a concept that is central to much of what is done - and much of what is done wrong - in digital photography. The second document deals with how the loss of "color integrity" in digital photographic images is extremely common and is largely an unrecognized effect of practices that have become fairly standard. The third document deals with the conversion of film color negatives to digital positive images, where misinformation, most of it unintentional, is rampant. The fourth document is more recent and represents a real breakthrough in understanding color integrity. This domument is less formal and mathematical than the other three, compartmentalized with completely math-less explanations while optional sections treat the math for those who are interested.

We have developed a group of powerful and flexible Photoshop filter plug-ins for PCs that operate according to the findings in these documents. ColorNeg inverts color negatives and ColorPos operates on photographic images from positive sources including scanned slides and digital camera images. The GamSat plug-in allows adjustment of saturation, gamma, and hue in a manner that preserves color integrity insofar as that is possible. We have very enthusiastic users of these plug-ins. See our Photoshop Plug-Ins Page for full details.

There are also four much less mathematical web pages on these same topics. The newer fourth document is nearly the same in both versions, however.

1. Silver-Based Gamma, Video Gamma and Levels.
2. Color Integrity in Digital Images.
3. Color Balancing Color Negatives.
4. Complete Color Integrity.

When you download the mathematical PDF files you will find that they are viewable but not printable. We believe this will be adequate for people who do not intend to study them, but please contact us if you want a printable version. When we posted similar documents in the past we got quite a few downloads but very little feedback. We really need to know if and how people are finding these documents useful, and this seems one of the few ways we have to encourage feedback. We are aware that the no-print can be defeated easily enough, but again we ask that you contact us instead. E-mail us at (
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