High resolution imaging becomes increasingly difficult as the atmosphere becomes less stable. Imagine trying to read the fine print on a newspaper at the bottom of a pool with a rippling surface. But there is a way to partly beat the effects of the atmosphere, and that is to take many very short exposures, and select through them for the few that happened when the air was briefly still. Expensive astronomical cameras offer no help here, because they are designed for long exposure imaging. Instead, some of the best high resolution planetary images these days are coming from video cameras, which are very good at taking many fast pictures. A particularly simple and inexpensive approach to this is using a webcam, which is a video camera and frame grabber combined. Now 1/30 second, or 1/100 second isn't very long to collect light, so the source needs to be bright. This is a technique for imaging planets, not deep-sky objects.

With care, a telescopic image like this:

Ends up being processed into this:

The original data is collected as a movie. There are several software tools available for splitting the movie into individual frames and working with them. I'm using K3CCD Tools, which is available here.

Many webcams may be used. Those that use CCD sensors generally work better than those using CMOS. I'm using a Logitech Quickcam 4000, which has a good quality CCD and a chipset that allows a lot of control over exposure time and frame rate. The QC 4000 is easily modified so that it can be attached to a telescope: