Practical guide / Interval Atlas
Time-lapse interval versus shutter speed: two different clocks
Understand start-to-start timing, capture delays and the time left for processing between exposures.
The interval controls when frames begin
A start-to-start interval of 10 seconds means the camera attempts to begin captures at 0, 10, 20 and 30 seconds. It does not mean that every exposure lasts 10 seconds. The shutter setting controls how long light is recorded inside each capture slot.
Not every timer defines interval identically
Some workflows express a delay after the previous exposure finishes. If a two-second exposure is followed by a ten-second delay, starts occur about twelve seconds apart before additional overhead. Read the camera or intervalometer documentation and use the same convention throughout your plan.
Reserve time for more than the shutter
Processing and file writing may take additional time. Some long-exposure noise-reduction modes also take a dark frame. The budget checker can model an equal-duration dark frame when that matches your equipment, but buffer overlap and other camera-specific behavior are not modeled.
Test the slowest expected condition
A bright scene may use a short exposure at the start of a shoot, while a darker scene later uses nearly the entire interval. Test the longest expected exposure and inspect file timestamps from a trial. Consistent arithmetic at the beginning does not establish consistent capture throughout the session.
Put the method to work
Check whether a planned exposure, write allowance and optional equal-duration dark frame fit inside your start-to-start interval.
Open the calculator →Before you use the result
Check the measurement units, use the actual materials or equipment in your project, and test a small example. The linked calculator shows its assumptions and provides a worksheet you can keep with your project notes.
These examples were prepared for this site. They are not a report of a laboratory test or a product certification.