Astronomik 31 mm Dark Frame Filter
For CCD camera models without a mechanical shutter, a dark frame filter like this round 31 mm threaded cell formatted example from Astronomik is a must-have. The main purpose of this filter is to permit the capture of dark frames without the inconvenience of having to keep an eye on your imaging system. Furthermore, this opaque filter is even better suited for use with a filter wheel. The combination of a filter wheel and this filter allows for dark frames to be taken without the need for your telescope to be capped off.
The use of an Astronomik Dark Frame filter is imperative for Interline CCD camera models that don’t include a mechanical shutter from the likes of Starlight Xpress, Imaging Source, Atik, and others.
