More on TTG and "light"

All about “light”

TTG couples the behavior of “light” (the root of photography) with the requirement of showing “what the camera lens saw” (the root of TTG).

1a. “Light”-related aspects = “tones and colors”

1b. Non-“light”-related aspects = “forms and shapes”

More on 1a | More on 1b
2a. Every aspect of everything depicted in photographs is either “light”-related or non-“light”-related.

2b. But most depictions of things in photographs have both non-“light”-related aspects and “light”-related aspects.

More on 2b
3a. “Tones and colors” do NOT always stay the same when a photograph is reproduced in a new format

3b. But “forms and shapes” DO always stay the same when a photograph is reproduced in a new format

More on 3a | More on 3b
4a. Because of 3a and 4a, viewers expect some changes to “tones and colors” (for example, color adjustments, increasing or reducing contrast, and correcting for under- or overexposure)

4b. But because of 3b and 4b, viewers are suspicious of changes to “forms and shapes” (for example, adding, deleting, replacing, resizing, moving, blurring, or reshaping depictions of things within a photograph)
5a. In light of 4a, TTG does allow “tones and colors” to be changed as necessary to avoid misrepresenting “what the camera lens saw”

5b. In light of 4b, TTG does not allow forms and shapes to be changed at all except in a few select ways

5a reflects P7 of the Trust Test
5b reflects P2 of the Trust Test
6a. Because of 3a (above), a photograph is still considered “undoctored” when “tones and colors” are changed to avoid misrepresenting* “what the camera lens saw”

6b. Because of 3b (above), a photograph is considered “doctored” if it undergoes any changes to “forms and shapes” (apart from a select few changes that are allowed by TTG because those changes are built in to billions of devices; see FAQ #800).

The definitions of “undoctored” and “doctored” used on this website

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*“misrepresentation” is judged by rinairs in P7

For more, see the FAQ on Light

1a. “Light”-related aspects = “tones and colors”

2a. Every aspect of everything depicted in photographs is either “light”-related or non-“light”-related.

3a. “Tones and colors” do NOT always stay the same when a photograph is reproduced in a new format

4a. Because of 3a and 4a, viewers expect some changes to “tones and colors” (for example, color adjustments, increasing or reducing contrast, and correcting for under- or overexposure)

5a. In light of 4a, TTG does allow “tones and colors” to be changed as necessary to avoid misrepresenting “what the camera lens saw”

6a. Because of 3a (above), a photograph is still considered “undoctored” when “tones and colors” are changed to avoid misrepresenting* “what the camera lens saw”