Unstable time-lapse exposure
QI shoot a lot of time lapses on my Nikon D610, and although I have always experienced some degree of aperture flickering, in recent months it has become a lot worse. I shoot mostly on aperture priority for changing light conditions and somewhere between f/8-f/16. I’ve read various forums and blogs that say flickering is unavoidable, but my fluctuations appear to be on every other photo and so big (sometimes +/- 0.5 EV) that it can’t be normal. Mylo Wilkin (AP forum)
AFundamentally, large frame-to-frame variations in the brightness of the scene are potentially unavoidable if the actual conditions are variable. A prime example would be if broken cloud was moving across the sun. It may be that some careful choice of the shot’s interval time might be required. A shorter interval could smooth out the brightness differences. Another thing to look at is whether your choice of metering area selection is being influenced by something in the scene changing brightness when the rest of the scene isn’t. Taking things from the opposite perspective, you could use spotmetering to target that part of the scene you want to be exposed correctly the most. If, however, the exposure ‘flicker’ happens even when the ambient light is quite constant, then this points to an issue with the camera. Try shooting in shutter priority mode to eliminate such a possibility.