In short, my question is: what are the best metering strategies when shooting a time lapse sequence to avoid visible fluctuations in brightness? I'd like to make the day-to-night transition look smooth.
This is my first try at making a time lapse video. The frames are unprocessed, they're just stitched together. Ignoring other problems and mistakes I made, one annoying problem is the fluctuations in the brightness of the image. What is a good strategy to avoid these? During this sequence, I set the metering to "matrix mode", but there are still several jumps in brightness. An obvious strategy would be using manual settings and fixing both the shutter speed and aperture at constant values. Obviously this won't work during dusk---the shutter speed went from 1/2000 to 1/4 during this sequence.
Since in this particular shot the middle of the picture is clear sky, I thought of trying spot metering next time, so the passing cars and light in the background won't have such a high impact. But I'm not at all sure it will be better. Also, it's impossible to tell if someone will shoot some fireworks right in front of that metering spot (fireworks are very common here). What do you think?
Finally, I thought of hacking the program I used to control the camera, and adjusting the camera settings from the program continuously according to a predefined curve. (I can get the curve from the sequence of shots I already have.) This is a lot of work though, so I'd only use it as a last resort.