If you are going to shoot longer than 30 sec, shooting on a night without the moon adding light allows the ambient starlight to light the landscape.
If the moon is out and bright, then the landscape will be overexposed before you can get good star trails by shooting with shutter speeds longer than 10 minutes or so.
On a dark but starlit night, try shooting about 2 to 3 minutes, at f4 or 5.6, iso 200 to 400.
Experiment, and be aware that the image viewed on location in the LCD will appear to be a lot brighter than it will appear on the computer screen, because your eyes will be adjusted to the ambient light. It is very easy to greatly underexpose and not know it until you get it on the big screen. One way to avoid that is to use the histogram, and another is to have a correctly exposed daylight shot on the card for a reference, so that you can compare brightness of a well exposed image to the ones you are shooting while out on location.
If you want concentric trails around a point, you have to line up your camera so that the North Star, or Southern Cross is in the image. If you want vertical trails, point the camera east or west when shooting. |
