Old thread, sorry, but I had a mysterious red streak problem in a Nikon D800, with 70-200 f/2.8 (VR-I, which was not on), which I cannot explain or reproduce. These are star pictures, Andromeda here, at about ISO 3200, f/2.8, 20 seconds, at 190 or 200mm.
The red streak was Not in Any 14-24mm image, but in Every 70-200 image, sorted here before I gave up on trying to work around it:
Yes, I know 20 seconds is better at 14mm, and clearly way too long for 200mm, unless guided (but I did not take that). This was not the best night (cool, falling from 60F to near 40F before I left, and windy and dry, and a large moon rising in another hour or two). I was only intending a quick trial run of D800 camera and high ISO, using only a tripod.
The red streak was very evident of course (not in dark viewfinder, but in rear LCD result), and was a constant in that one lens, and at the time, I carefully inspected front and rear lens elements looking for something red on it, but it seemed very clean and clear.
Any suggestions about a cause would be appreciated, however, I may be unwilling to consider any about external light, because (arguing with myself), because it was deep rural dark - at an astronomy club dark site 100 miles from the big city, and the point of being there was simply that no light is allowed there. Also the site happened to be empty, I was alone. It was rather dark, and the lens was also aimed up, where there isn't anything. And even if there had been, something has to change when the lens direction is changed east or west, and it didn't. Surely it had to be internal somehow? The viewfinder was not closed, but there simply was no possibility of any external light, honest. I went from the 70-200 back to 14-24, then back again, and back again, and one lens always did it, the other never did.
I could Not recreate the problem at home next night with similar sky exposure, however the city sky is at least four stops brighter, white at this exposure.
I also tried in a pitch black closet (similar settings, 20 seconds, high ISO, infinity focus at 200mm, etc), and got a pitch black image.
Yes, I did use a dim red flashlight a few times, but carefully and sparingly, and not during any exposure. Logic would imagine it must be related, that somehow it affected something in the lens? Really does not seem possible, but the same in every image? (it was never on during any exposure, and rarely otherwise). So some kind of phosphorescent memory? I cannot recreate any issue from it either. At home, I did try shining it directly into the open viewfinder from only an inch or two, for the full 30 second exposure in the dark, and it did make the frame somewhat pink then, not in the same way, and of course nothing remotely like that happened before. That might affect metering, but it takes a lot to get into the frame, and there was not a lot of anything at this dark site.
It simply could not happen, yet it did. The only plausible cause would seem to be some kind of internal red light, but that does not seem rational, and does not explain why it stopped at home.
Anyway, it seems interesting, but hopeless in understanding...