The Mamiya CS 2.8/21mm is one of the rarest and finest Mamiya CS lenses, along with the 3.5/45-90mm and the 3.5/14mm Fisheye. During the last ten years I've seen only three lenses for sale. The serials on my sample are indicating it was about the 150th Sekor CS 2.8/21mm ever made.

The Sekor CS 2.8/21mm is one of the smallest lenses of its class; only the well known Olympus Zuiko 3.5/21mm is even smaller. While the optical performance of the Olympus Zuiko 3.5/21mm is severly compromised by its small size and simple construction (seven lenses only), the Sekor 2.8/21mm performs rather well: While the extreme corners are really unsharp in the f2.8 to f5.6 range, the remaining image is very good. For landscape images on 24 MP full frame cameras it would be best to use f11 though.

		MAMIYA SEKOR CS 21mm 1:2.8                  (10 Linsen / 8 Glieder)