Notes on time-lapse photography, mostly for myself.
A good starting point is the 180° rule borrowed from cinema: keep the shutter open for about half of the interval. Clouds at a 4 s interval look smooth with a 2 s exposure; city traffic needs an ND filter to get there.
Aperture flicker comes from the lens stopping down slightly differently between frames. Shooting wide open or twisting the lens a few degrees off the mount (manual aperture lock) removes most of it. The rest is handled in post with a rolling average of frame luminance.
Ramp ISO and shutter in small steps, never more than 1/3 stop between frames, and smooth the exposure curve afterwards. Keep white balance fixed in camera and grade it later.
ffmpeg -framerate 25 -pattern_type glob -i '*.jpg' -c:v libx265 -crf 20 out.mp4