The right time-lapse interval is the real event length divided by the number of frames you need. Work out the frames from your finished clip length and playback speed, then divide. For example, a two hour event turned into a 10 second clip at 24 frames per second needs an interval of 30 seconds.
The Simple Formula
- Choose your finished clip length in seconds.
- Multiply it by your playback frame rate to get the number of frames needed. A 10 second clip at 24 fps needs 240 frames.
- Convert the length of the real event to seconds. Two hours is 7200 seconds.
- Divide the event length by the frames needed. 7200 divided by 240 is 30, so shoot one frame every 30 seconds.
You can also reverse it. If you set a 5 second interval and shoot for one hour, you capture 720 frames, which makes 30 seconds of video at 24 fps.
Typical Intervals by Subject
These are general ranges to adjust after a trial run.
| Subject | Typical interval |
|---|---|
| Fast clouds, busy traffic | 1 to 3 seconds |
| Slow clouds, sunsets, sunrises | 3 to 10 seconds |
| Crowds, city scenes | 2 to 5 seconds |
| Moving shadows, building work | 30 to 120 seconds |
| Plants growing, long projects | Several minutes to hours |
Camera Settings That Support the Interval
- The interval must be longer than your exposure time plus a second or two for the camera to save the frame.
- Use manual exposure where light is steady, so brightness does not jump between frames.
- Use manual focus and a fixed white balance for consistency.
- Choose a shutter speed of roughly double the frame rate, or around 1/50, if you want a little motion blur in moving subjects.
- Turn off image stabilization on a tripod, and turn off screen playback to save battery.
Check Battery and Storage
Before you begin, multiply the number of frames by the file size to see how much card space you need. Raw files fill cards fast. Check that your battery can last the full session, or use external power for long projects. Many cameras can run an interval timer built in. If yours cannot, a separate intervalometer will do the job.
FAQ
What if I am not sure how long the event lasts?
Choose a shorter interval than you think you need. You can always drop frames in editing, but you cannot add frames you did not capture.
Can I change the interval later?
Not in the camera, but you can speed up or slow down the final clip by using fewer or more frames in your video software.
The Short Version
Divide the real event length by the frames you need, where frames equal clip seconds times playback frame rate. Check that the interval is longer than the exposure plus saving time, lock your exposure and focus, and make a short trial run first.
