For those of you who have an interest in photographing the "night-sky" below are some tips and techniques for capturing the night sky!
1) Be sure to clean your optics (front and rear) before starting your photography session.
2) Be sure that your tripod extends high enough so that you camera is level with your eyes and you won't have to bend over. Avoid extending the center column since this would turn your tripod into a monopod and create less stability.
3) A carbon fiber tripod with a quick release and ball head is best. Bogen Manfrotto, Giotto, Gitzo and Slik are a few of the best.
4) A tripod and remote shutter is mandatory for astrophotography.
5) Focus your lens on "infinity" before it gets dark or you can also put a piece of glow in the dark tape as a marker of your infinity setting.
6) Use the "mirror lockup" technique for extra stability.
7) Astrophotography is the toughest test on your optics since we are trying to capture very distant celestial objects in extreme low light while obtaining sharpness and composition.
8) Be sure to turn your lens stablizer to OFF when on a tripod.
9) Be sure to set your lens to Manual Focus (MF) when astro imaging.
10) You can use the shutter priority (Tv) or (S) setting, the Manual (M) or the Bulb (B) setting.
11) Use red light (to preserve night vision) only.
12) Star trails can be captured with one exposure if using film but with digital you would need to capture many images about 2 seconds apart and then combine in Photoshop.
13) The longer the lens focal length such as 300mm as opposed to 50mm the shorter the exposure must be to avoid star trailing on your images.
14) Use the "500 rule". Divide the focal length of your lens into 500 and this will tell you how long you could keep the shutter open to avoid star trails. e.g., 50mm lens, set for 50mm divided by 500 = 10 seconds
15) If you want the star trails in your image, set camera shutter using the "500" rule above.
Hope this has been helpful!