Photos of night sky timelapses are raw material for a startrail photography at the same time.
But even a 2-3 seconds "buffer" time between the shots in interval mode produces gaps in the trails (the gaps then represent up to 10% of the total exposure time). And if you set the buffer time too short you are in the risk of getting a >30 second gap because the interval timer misses a complete shoot every now and then.
So I found that in cases where exposure time is not longer than 30 secs it works much better to use continuous shooting mode on the camera together with a remote control with shutter lock instead of using interval mode. In continous shooting mode with e.g. 30 seconds exposure there is absolutely no gap between the exposures.
Instead of using a "normal" remote perhaps TRIGGERTRAP is also an option, especially because it also features timelapses with accelerating "time warp" effect by variating the exposure time during the timelapse session.
Clear skies!
Peter
P.S. If there is no remote control and no Triggertrag you can help yourself even unsing piece of tape and e.g. a small pebble hold down the trigger knob. Works great. The first and the last shoot must then be discarded due to camera shake.
Last edited by Pete_XL; 04-13-2015 at 02:53 AM.