Calculate
Method and assumptions
Playback seconds = whole frames ÷ playback FPS. Target frames = ceiling(target seconds × FPS). First-to-last shot-start span = (frames − 1) × interval. For a shooting window [0, D), with the first shot at 0 and the end excluded, frames = ceiling(D ÷ interval).
Worked example
720 frames at 24 fps play for 30 seconds. At a 5-second interval, the first-to-last shot-start span is 3595 seconds. A 3600-second window [0, 3600) contains 720 starts.
Limitations
The window convention is a generic planning model, not a camera-specific promise. Exposure duration and final exposure completion are not included. No camera control, timing guarantee, or exposure advice is provided.
Frequently asked question
Why does the first-to-last span use one fewer interval?
The first frame begins at time zero, so 720 starts create 719 gaps. A full 3600-second window still contains the final start at 3595 seconds.
References
Nikon time-lapse documentation. These are reference sources, not endorsements.