Yesterday, I took the photo of DFA90mm/2.8 prototype from the top at CP+ (Cameras show). As you see, there is black ring thing inside the lens. I wonder what it is. Do you have any thoughts? Yoshi
A black ring? There are several and they are just the metal parts that hold the lens elements.
First camera 1953, first Pentax 1985, first DSLR 2006