Any tips on long exposures?

[tbab]

Hi all,

I am heading up to the north of Scotland next month (Isle of Skye) where is should be very dark. I would love to take a photo of star-trails, has any one got any tips for me. I think the best way to do it is to take multiple exposures and stack them.

I'll be using a Canon 20D so I'll have full control of the camera. So what white balance is best to use. Should I shoot RAW or will it not make too much differnce after stacking etc, etc etc.......

Thanks for your help.

Tom

[andyschlei]

I can't help with the digital camera side, but here is my recommendation.

Put your camera on a tripod and get the shutter on a cable release or other isolated trip mechanism.

Point the camera at the sky and open the shutter. Leave it open as long as you can, but depending on local brightness, I'd limit that to 20 minutes or so.

Since you are going for trails, multiple stacked exposures might leave gaps between exposures. Long, single exposures should be the best. Although I know AutoClub as made some very nice star trail pictures with multiple stacked sots.

I did this during the Perseids this year and have this result (http://obsballona.net/coppermine/displayimage.php?pos=-58). That shot is about 15 minutes with a 35mm f1.4 Nikkor lens on ISO 400 film. Scanned result processed in PixInsight (http://www.pixinsight.com/) and Photoshop.

Clear skies and good luck,

--Andy