Time-Lapse Calculator

Knowledge Base

How Time-Lapse Interval Math Works

A time-lapse compresses a long event into a short clip by capturing far fewer frames than the final playback rate implies. The total number of frames you need is simply your target clip length multiplied by your playback frame rate. A 15-second clip at 30fps needs exactly 450 frames, regardless of how long the real event lasts. The shooting interval is then just the event duration divided by that frame count.

Choosing a Clip Length That Feels Right

Shorter target clips (10 to 20 seconds) suit fast-changing subjects like clouds or traffic, giving a punchy, energetic result. Longer clips (30 to 60+ seconds) suit slow subjects like construction projects or seasonal change, where you want the audience to sit with the transformation rather than blink and miss it.

Why Storage Adds Up Fast

Time-lapses often need far more storage than people expect, because you're capturing individual full-resolution stills rather than a compressed video stream. A single day-long time-lapse at a reasonable interval can easily produce thousands of RAW files. Shooting JPEG instead of RAW, or using an in-camera intervalometer video mode, trades some post-processing flexibility for a dramatically smaller card and faster edit.

FAQ

Q: What if my calculated interval is faster than my camera can write frames?
A: Check your camera's minimum interval for your chosen resolution and format (RAW is usually slower to write than JPEG): if the calculated interval is shorter than your camera can sustain, either lower resolution, switch to JPEG, or accept a longer final clip.

Q: Should I shoot RAW or JPEG for a time-lapse?
A: RAW gives you far more room to fix exposure and white balance shifts during a long shoot (especially at sunset/sunrise), but produces much larger files, for events where lighting is stable throughout, JPEG is usually the more practical choice.

Planning a time-lapse before you start it

Three numbers define a time-lapse and fixing any two determines the third. How long the event lasts, how long the finished clip should run, and the playback frame rate together give you the shooting interval. A one hour event cut to ten seconds at 24 frames per second needs 240 frames, so the camera fires every fifteen seconds.

Choose the interval to suit the subject's speed rather than the arithmetic alone. Clouds move quickly enough for a few seconds between frames. Shadows crossing a room want tens of seconds. A construction project or a plant growing wants minutes or hours. An interval too long for the subject produces jerky motion no amount of processing smooths out.

Shutter speed matters as much as interval. Each frame frozen with a very fast shutter produces a strobing, stuttery result, because there is no motion blur linking one frame to the next. Aiming for a shutter around half the interval, which usually needs a strong neutral density filter in daylight, gives the smooth movement people associate with a good time-lapse.

Check power and storage against the full duration before starting. A shoot lasting six hours at a five second interval is over four thousand frames, which is a serious amount of card space in raw and more battery than most cameras hold internally. Discovering either limit three hours in wastes the whole attempt.

Lock everything that can drift. Autofocus hunting between frames, automatic exposure adjusting to a passing cloud, and automatic white balance shifting all produce flicker in the finished clip. Manual settings throughout are the norm, and the one common exception, a gradual exposure change across sunset, is a deliberate technique needing its own handling rather than automation.

Vocabulary

Interval. The time between one frame and the next. Together with the event duration and playback frame rate it determines how long the finished clip runs and how fast motion appears.

Neutral density filter. A filter reducing the light reaching the sensor without changing colour. Lets you use a slow shutter in bright conditions, which is what produces motion blur between time-lapse frames.

Flicker. Rapid brightness variation between frames, usually caused by automatic exposure or aperture adjusting slightly each time. Prevented by locking settings manually, and difficult to remove convincingly afterwards.

Holy grail. A time-lapse spanning a large change in light, such as day into night. Requires exposure to change gradually through the sequence, which conflicts with locking settings and needs specific technique.