DIY star tracking
To take photo's of the stars even modern digital camera's require exposure times from 10's of seconds to a few minutes or more. However any exposure over a few seconds, especially with a telephoto lens, will show 'star trails' (caused by the stars 'smearing' as the Earth turns). To take 'pin sharp' photo's requires a camera mount that counteracts the movement of the Earth. One such (that can be constructed using basic wood-working skills) is the 'Barn Door' or 'Haig Mount' and is described here.