How this calculation works
Start the first exposure at zero. Each next exposure starts one interval later and counts only if its full exposure finishes within the capture window. Divide frame count by playback FPS for clip duration.
Frames = floor((capture window − exposure) / interval) + 1 when the first exposure can completeA worked example
A one-hour window with ten-second start intervals and one-second exposures records 360 complete frames. At 30 FPS the clip lasts 12 seconds; at 20 MB per image the source images total 7,200 MB.
Good to know
Ideal schedule only. Dead time is a minimum constraint, not added twice. Storage excludes filesystem overhead, video output and backup. No real camera, battery or buffer guarantee.
Reference: Nikon: interval and time-lapse photography (opens in a new tab) ↗
Define the interval before counting frames
This tool treats the interval as start-to-start time. An exposure and its minimum recovery time must both fit inside that interval. Other cameras may describe a delay differently, so match the input to the actual control semantics.
Adding exposure duration again to a start-to-start interval would silently lengthen the schedule. Here exposure time affects whether a frame completes and whether the selected interval is feasible.
The shutter angle and exposure time calculator adds convert shutter angle and exposure milliseconds at a chosen frame rate, with open-time diagrams and an explicit light-cycle timing comparison.
The first and final exposures need explicit rules
The first frame begins at time zero. A frame that starts before the window closes but finishes after it is not counted. These endpoint rules avoid the usual one-frame ambiguity in a simple duration-divided-by-interval estimate.
A window shorter than one exposure contains zero complete frames. A window exactly long enough for the first exposure contains one. The event table makes those decisions inspectable without enumerating every frame.
Capture storage and finished video are separate budgets
Saved image size multiplied by frame count estimates the source-image storage in decimal megabytes. A finished video depends on codec, bitrate and editing choices, so it is not inferred from the image files.
Playback FPS changes the clip duration without changing the capture schedule. A longer exposure changes the schedule constraints and total shutter-open time, but does not automatically predict motion blur quality or eliminate flicker.
Use the result with the next measurement
The shutter angle and exposure time calculator converts an angle at a selected frame rate into exposure milliseconds. Its result can help specify an exposure scenario here, but playback FPS and capture exposure remain separate inputs.
Ideal schedule only. Dead time is a minimum constraint, not added twice. Storage excludes filesystem overhead, video output and backup. No real camera, battery or buffer guarantee.
A few questions, answered
Does interval include exposure?
Yes, it is start-to-start; exposure plus minimum dead time must fit.
Is an incomplete final exposure counted?
No, it must finish within the window.
Does playback FPS change captured frames?
No, it changes clip duration only.