#10 in a series of background briefs

TTG and “light”

  • “Light” is a big deal

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

  • What to know about light

    Some “light”-related aspects (tones and colors) always change on their own when photographs are reproduced in a different format...

    . . . but non-“light”-related aspects (forms and shapes) never change on their own when photos are reproduced in a new format.

    (This is explained in #1-7 below)

  • How TTG uses the behavior of light to “draw the line” on manipulations

    A. After exposure, “light”-related aspects (tones and colors) must be changed if the way they were recorded misrepresents the scene (per P7)...

    — but —

    B. After exposure, non-“light”-related aspects (forms and shapes) cannot be changed — except in a few select ways, as per P2—

    . . . not even when changing forms and shapes would make the photograph “look more like” the scene depicted.

    (This is explained in #1-7 below)


Want to know more? The rest of this page explains the “Why”

  • 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. For “tones and colors,” cameras do NOT always record exactly “what the camera lens saw”

    3b. But for “forms and shapes,” cameras DO always record exactly “what the camera lens saw”

    More on 3a | More on 3b

  • 4a. “Tones and colors” do NOT always stay the same when a photograph is reproduced in a new format

    4b. But “forms and shapes” DO always stay the same when a photograph is reproduced in a new format

    More on 4a | More on 4b

  • 5a. 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)

    5b. 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)

  • 6a. In light of 5a, TTG does allow “tones and colors” to be changed in whatever ways necessary to avoid misrepresenting “what the camera lens saw”

    6b. In light of 5b, TTG does not allow forms and shapes to be changed at all except in a few select ways

    6a reflects P7 | 6b reflects P2

  • 7a. Because of 3a and 4a above, a photograph is still considered “undoctored” when “tones and colors” are changed to avoid misrepresenting* “what the camera lens saw”

    7b. Because of 3b and 4b 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 “baked in” to billions of devices)

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

    _______________
    *Regarding 7a, as per P7 “misrepresentation” is judged by rinairs


For more, see the FAQ on Light