Vivitar 55mm f2.8 Auto
I was eager to test this lens. This is a Cosina made lens. It is a well made lens. This lens offered manual aperture or full auto on the main aperture ring. It is like a TX lens that had a mount change. I expected this to be tack sharp. Well, it is and it isn't.
Wide open it is soft. It tightens up a tad at f4. Like a typical Cosina it sharpens up at f5.6. I've seen some great shots from the Cosinon version of this lens. In good light at f5.6 and up I believe it can produce excellent images.
Color rendition is a tad flat. Contrast is low at 2.8 and excellent by f5.6. Shadow detail is decent but it's no Hexanon. Highlights blow out at f2.8 but fall in line at f4.
The surprise with this lens is it's control of abberations. Fringing is very well controlled. Flare is also well controlled. It feels like a scientific lens.
I also noticed that it renders b/w well.
Handling on the T2i is underwhelming. It's a bit of a chore to achieve critical focus. Tnat's as much the T2i's fault as it is the lens' fault. It is solid but the weight balanced well on the T2i. Focus is siljy smooth. F-stops click nicely into place.
Note: When I received this lens it was adjusted to focus well beyond infinity. I adjusted it back to factory spec.