I have a 3DS. It can take stereoscopic photos, albeit with a low-res and noisy sensor. I'm not expecting great photos, however, I am seeing one issue I can't explain simply by cheap sensors. In some lighting conditions, when I take a picture, one of the pictures turns out much darker than the other. It's not predictable whether it's the left or right camera, but it's often one of them.
The only thing I can think of is that it it's related to fluorescent lighting - that it takes the photos serially and one of them takes place just late enough that the bulb has done a half-cycle, resulting it in being either lighter or darker, and then it doesn't do separate color-correction. In my test cases it has never happened under incandescents or the sun, but happens regularly - but not always - under fluorescents. (However, the sample size is biased because we only have one incandescent light in our apartment.)
But I know jack about cameras and lighting. Does this explanation sound reasonable? Has anyone else run into similar problems taking stereoscopic photos? Since the camera is useless except for quick spur-of-the-moment shots, can I do anything to compensate for it?