Astronomic 1.25" Dark Frame Filter
The 1.25" Astronomic Dark Filter is essential for a CCD camera that doesn't have a mechanical shutter. This filter allows you to take dark frames without the hassle of monitoring your set up. The filter is opaque and threaded in a 1.25" cell. This filter works even better with a filter wheel. Attach this filter to a filter wheel in order to take a dark frame without capping off your telescope.
The Astronomic Dark Frame filter is a must-have for many cameras that don't have a mechanical shutter, including interline CCD cameras from Starlight Xpress, Imaging Source, Atik, as well as others.