While doing a time-lapse, why does the capture time vary?
The actual capture time will vary because of the way the Windows operating system works. Windows is not a “real time” OS. The Windows Task Manager allocates time among all the processes running on the computer according to a priority scheme. There is no way for a client program like GBTimelapse to force Windows to give it time. The capture time is shown in red if it is longer than the time interval you asked for. If you see this happen, you should increase the time interval.