The calculation
start-to-start interval = capture seconds ÷ frames
photo storage in GB = frames × MB per photo ÷ 1,000
Worked example
A 60-minute session made into a 10-second clip at 30 fps needs 300 frames. Divide the hour into 300 capture slots: a 12-second start-to-start interval. At 25 MB per photo, source images use 7.5 GB.
Understand the endpoint convention
This plan divides the capture window into complete slots. The first exposure starts at zero, and the final exposure starts one interval before the end of the window. If you instead require a frame exactly at both endpoints, divide the duration by frames minus one. Camera timers do not all use the same convention.
A time interval is not an exposure recommendation
The interval describes how often a frame starts. The shutter exposure and write time must fit inside it. Use the exposure-budget tool to check the allowance. Subject movement, desired blur and available light still determine the photographic choice.
The calculator rounds up to a whole frame, so the exact playback length can be slightly longer than requested. It budgets source stills only. An exported movie, working copies, previews and backup storage require additional space.
Common questions
Why does the frame count round up?
A frame cannot be fractional. Rounding up gives at least the requested playback duration at the selected rate.
Does it work at 23.976 fps?
Yes, as a decimal estimate. Enter 24000/1001 as its decimal value if you need a closer approximation. This is not a drop-frame timecode converter.
Further reading
Official or original references for the workflow; these organizations do not endorse this independent tool.