Tamron 28 mm f/ 2.8 Adaptall model CW-28 is a wide-angle fast prime lens for 35 mm SLR cameras popular in the 1970-90s (via the interchangeable Adaptall/Adaptall-2 mount).
It is multicoated. The lens shows very good sharpness and contrast. There is a slight fall of resolution on the edges. It also came in silver design (see the last photo).
There is a rare version of the lens, produced in black and silver design. The key difference from the later variant is a different filter diameter (55 mm vs. 52 mm). The 2nd, 3rd and 4th photos present this very version of the Tamron 28 mm f/ 2.8 Adaptall lens.
The Tamron 28 mm f/ 2.8 Adaptall had specific advice for landscape and interior photography.
This lens is something really good wide open sharp from corner to corner even on APS-C sensor cameras, really rare this in manual focus wide lens.
Weakness is the 5 aperture blades but who needs it? if wide open is sharp already. Like all wide lens has some distortions. Rare to find
The second version of this lens with 2.5 aperture and 49mm filter is a little bit better than this but not much big difference. Abut how great is this lens I post one test photo made with wide open from my computer screen.