Imaging the Night Sky

Imaging the night sky is called astrophotography.

Images of the stars at night including the Milky Way can be obtained quite simply using a mobile phone or DSLR camera and a tripod.

However, if we want to get more detail in the images we need longer exposure times. The problem here is that when exposure times exceed around 25 seconds we will begin to see 'trailing' of the stars, due to their movement across the night sky; although, sometimes we might actually want this effect in our image, which is fine. However, most times we want round stars in our image, and for some of the faint deep sky objects we may need exposure times of several minutes. Therefore in order to maintain pin point stars we need the camera to be able to track stars across the sky. We can do this by placing the camera on a tracking mount. Tracking mounts can vary from a simple star tracker to a sophisticated computer controlled mount.

The camera we use can be a mobile phone for wide field of views, a DSLR type camera or a dedicated astrophotography camera. We can use a normal camera lens or we can attach the camera to a telescope (which is basically acting as a large telephoto lens).