At the Telescope
Before we venture off into the practical side of a typical video imaging session under the stars, it is worth mentioning just a few of the commonly employed camera accessories and configurations you may find useful. Some configurations may require the use of threaded step rings or other adapters to allow for successful attachment.
4.1 Focal Reducers
Focal reducers are great for producing a wider field of view, especially when using cameras with small CCD image sensors. They essentially reduce your telescope's focal length so that it performs like an instrument with faster optics of the same aperture, yielding brighter images. Some can introduce coma (elongated stars appearing around the edges of the field of view) and may require a coma correcting lens also to ensure a flat field of stars across the entire image.