This adapter is designed to greatly reduce vignetting when using a DSLR camera with a focuser, making good use of a much larger than standard 1.875" diameter inside EOS bayonet. The main body is precision machined aluminum that has been anodized black, and the bayonet itself is machined stainless steel with both the body and the bayonet baffled and painted flat black on the inside. The bayonet provides precise and solid camera connection.

Indeed, this adapter acts as the solution to a problem that has long assailed astro photographers; the small aperture of standard T-thread adapters causing serious vignetting issues when linking your DSLR Camera to a telescope. This was an especially harsh issue for those making use of the Astro-Physics 2.7" and 4" Prime Focus Field Flatteners; What good were pinpoint stars to the edge of a wide field when the edge of that field was darkened by the T-ring's vignetting effect? In this splendid adapter, a solution is provided to the above issues. The increased aperture mitigates the issue of Vignetting greatly, and this adapter is fully compatible with the 2.7" and 4" Prime Focus Field Flatteners.

A 48 mm internal thread allows the use of a filter in the optical path; however, double-stacking is not possible when used with a flattener. This adapter has a net spacing distance of 1.67" (42.4 mm). The spacing distance from the 48 mm internal threads (when using a BARADV or CCDT67) is 1.35" (34.4 mm). This adapter is designed to be used with the following: Current 2.7-inches Prime Focus Field Flatteners (67PF462, 67PF562 and 67PF582) and previous 2.7-inches and 4-inches Prime Focus Field Flatteners (67PF69, 67PF79 and S155EDFFF)

OPT Product Number: AP-67RLEOS