OK, So last night I braved the -7C temperature to take some shots of the stars, the purpose was two fold.
Fistly I wanted to create a star trails image, secondly I was going to use the shots to create a short timelapse movie
All was good, camera battery was fully charged, laptop was fully charged, I don’t have a intervalometer for my camera (yet) so I use my laptop to control the shutter on the camera. I set the camera on the tripod and pointed it at the sky, connected it to the laptop, set the shutter speed to 25 seconds and the told the laptop to take 240, 25 second shots every 27 seconds.
The extra 3 seconds are there to allow the camera time to process the image, I shoot in Raw for more control afterwards and my camera takes a couple of seconds to save it to the computer. (When using the USB connection it by passes the CF card and writes it directly to the laptop, this seems to take longer than normal.)
Cool, it was all set up and taking shots, I was freezing so, as I was shooting in my back garden, I went back inside the house.
20 minutes later I went out to check, still working, 10 minutes later, the battery on the camera died, about 30 seconds before the laptop battery died.
So instead of my 240 shots the battery only allowed me 64, which at 24 frames a second gives me a 2.5 second timelaspe movie whoohoo!
Anyway, below is the star trial image created from these 64 shots. Orion is the collection of bright stars in the bottom right corner.