The long exposure. Most all DSLR cameras are capable of taking star trail shots. A star trail is a streak of light in a long exposure shot that is created by star light. When photographing the stars at night the earths rotation cause the stars to move across the sky. Depending on how long your exposure is the trails will be short or long. The shot below took fifteen minutes to create.
Here is how it was done.
For star trails you want your camera to have as much light as it can get so bring the aperture (F#) down as low as your lens will allow.
Now ISO and shutter speed will take a bit of practice and patience. I normal will shoot at a lower ISO with my camera because it is very old and tends to get grainier at higher ISO. Newer cameras will be better equipped to handle the higher ISO and no light. This will still be trial and error to get the desired effect you want in your image. After a few practice shots you will see how ISO effects your camera.
Shutter speed is adjusted with the idea of how long you would like your trails to be. I typically do not go shorter than 15 minutes because shorter trails are not as interesting to me. But it is all up to your artistic preference.
You will need a few things.
Most importantly a sturdy tripod! If the camera moves at all even slightly during exposure your image will not have crisp clean trails. Also it is a good idea to have a remote control for your camera. This will insure you do not bump the camera when triggering you shutter. I have both the wired and wireless type, both work well for this. A flash or flashlight is handy for filling in light around and on your subject. The jeep in this photo was illuminated with a 1200 lumens flashlight. This will also take some practice, do a few practice shots shining the light on your subject. It may only take 3-5 seconds of light to illuminate your subject but it is a fine line between dark and light
One of the biggest things to remember when shooting movement in long exposures, and this goes for night time or day time, is a fixed point of interest. Your pictures subject should not be moving it should appear that thing are moving around it. For example this image is of the jeep, the star trails are just background.
If you have any questions feel free to email me at william@GilletteOutdoors.com