So you’ve arranged your composition, you’ve calculated the intervals and set up the ISO and shutter speed. When You get your completed sequence back play it… what’s this annoying flickering?
The time-lapse flicker is the Bain of most photographers and filmmakers. So first off, why does it occur? Well it could be a number of things. Firstly it could be the artificial lighting in the scene where the 60Hz (or 50Hz) power frequency produces a corresponding fluctuation in the light output of the lamps. It could be the cameras mechanical aperture where for each shutter press; the camera activates a mechanical device that moves the iris to the desired aperture. The aperture cannot be exactly the same size every time because of friction and other factors so there are differences in exposure.
That’s very interesting I hear you say but how do I fix it? Well The first (free) answer is to use After effects and its built in plugin called “colour stabiliser”. This plugin works just fine as long as you have a fixed light and dark point to which you can allocate the plugin’s markers. If however your image is constantly changing (as time lapses do!) then you will find it difficult to set two markers on fixed light and dark points. At this point I would recommend navigating towards granitebaysoftware.com and looking at their (not free) plugin GBDeflicker. This clever plugin utilizes a luminance graph and histogram to locate the relevant light sources to place markers that produce colour stabilisation. To see a more in depth explanation take a look at Granite Bay Software’s GBDeflicker PDF.
Here is an example of a time-lapse with the left side raw and the right side with the deflicker.