80x80mm filter holder for 77mm Hassel lens

This is a holder for 80x80mm color glass filters for Hasselblad CZ Tele-Tessar 250/4 lens. The lens has 77mm filter bayonet.

This was done to be a part of a portable astrocamera. Hence, as no movement of the camera is expected, the 80x80 side has open design for easier installation of up to 3 filters.

80x80mm is a standard color glass filter size for soviet filter sets.