Time-lapse refers to a shot that follows a transition in time, like an entire sunset in a matter of seconds, or the flowering of a plant in under a minute. It’s accomplished by taking a few frames over the course of a longer interval, and when shown at a faster frame rate, creates the illusion that the event happened in a much shorter time. It’s different from stop-motion photography, where the frame is manually exposed just once, and then time is taken to change the scene. Here, the interval of time between exposures can vary greatly. With time-lapse photography, the interval remains the same.
Using film, this is done with an intervalometer, a device that controls the movement of the camera to expose one frame at a time with a given interval of pause time in between exposures. When using a video camera, the picture cache holds the frames to be recorded, and then lays them down to tape once the cache has filled. Using the picture cache reduces the wear on the tape mechanism and stock that would be caused by pulling and stopping the tape for every single frame. When using a solid state recording device, like Panasonic’s P2 cameras or Sony’s SxS cameras, the function works by laying each frame to the media when it happens, since there are no moving parts to contend with.
In the example, above we are using the Interval Mode on the Sony EX1 with EX Slow Shutter. The EX Slow Shutter creates a lot of blur in the image, which creates a nice effect when combined with time-lapse recording. Here were my settings:
Interval Rec: Setting: On
Interval Time: 1 sec
Number of Frames: 1
EX Slow Shutter: 32 Frames
Video Format: HQ 1080/30p
Some cameras include a total take time and total record time calculation, this function allows you to see how long your event can last before you run out of media, and how long your shot will be when played back. If you know that your sunset shot needs to be 8 seconds long, this is a great tool to help you adjust your interval time.
Here are examples of time-lapse settings for a few cameras:
System Mode: 720-59.94P
Camera Mode: 60P
Interval Rec Mode: On
Rec Time: 00s01f
Pause Time: 00h00m00s29f
Result: 1 frame is recorded every half a second (if 60 frames is a full second, then 30 frames is half. If I record one frame and wait for 29 frames, added up, that makes 30 frames worth of time which has passed, with only one of those frames being recorded). At this setting, it will take 30 seconds to watch an event that took place over the course of an hour.
Cache/Intval Rec: M.INT
Number of Frames: 1
Trigger Interval: 1 sec
Video Format: 1080/60i
Result: 1 frame is recorded with 1 second between each frame. At this setting it will take 1 minute to watch an event that took place over the course of an hour and a minute.