time lapse
The time lapse is a cinematic method for accelerating the long-time recording of movements in which the frame frequency (frame rate) of the recording camera is reduced in proportion to the playback frequency. If the recordings are then played back at normal speed, the recorded process appears to be faster. This also makes changes visible that are difficult or impossible to perceive in real time due to their slow nature.
Technical requirements
In the case of short sequences, the individual film images can be recorded by hand; for long-term recordings, special, separate switching devices ( pulse generators ) and release magnets or single image motors are used. Better Super 8 cameras often have this technology, which usually also allow long exposures of the individual images. In the digital amateur segment, you can often find digital cameras and camcorders that have series image functions. Time-lapse recordings are also possible without the serial picture function, by cutting out single pictures from the film recordings using video processing software at regular intervals. In the semi-professional area, you can fall back on SLR cameras , whose recording interval z. B. is controlled with a computer. In the professional sector there are special cameras, especially for the film industry. For professional recordings, the same lighting conditions must always be ensured. This is still easily possible in a controlled environment such as a photo studio ; in the open air, depending on the recording interval, it becomes much more difficult. If recordings with an interval of a few seconds are still unproblematic, because the lighting conditions do not change so quickly, there may be strong fluctuations in brightness due to changed weather situations at recording intervals of several hours to days. This is particularly visible, for example, on recordings that document construction progress on buildings. The annoying flickering can be reduced in post-processing .
calculation
The following formula is suitable to find out all the settings that you need to create a time-lapse recording:
With
- = Number of images;
- = Film length (in s);
- = Frame rate;
- = Recording time (in s);
- = Interval (e.g. take a picture every 2 seconds)
Example: A camera runs at 12 frames per second. When the film is projected at the normal frame rate (for cinema ) of 24 frames per second, the result is a double time lapse.
See also
- Slow motion
- Film 80,000 shots
literature
- Gunther Wegner: Time-lapse photography: recording, editing and production of time-lapse videos. mitp; 2nd, revised edition 2014, ISBN 3-82669-724-3 .
- Andreas Becker: Perspectives from a different nature. On the history and theory of cinematic time lapse and time expansion. Transcript, Bielefeld 2004, ISBN 3-89942-239-2 .
