1. The TTG photographer has to record all forms and shapes pretty much the way they want them to appear in the final photograph, because — except for a select few allowable changes — all non-“light”-related aspects have to be left exactly as they were recorded. (See P2.)

2. TTG photographers have to forego applying their personal “style” if that style involves changing the look of the photograph to something other than “what the camera lens saw” (as judged by rinairs in P7). More on this

3. As this page explains, TTG photographers can retain most visual effects that were caused by factors before the light from the lens hits the recording surface—

—but after the light hits the recording surface, the photo cannot be doctored to simulate those same visual effects.