Takumar 135mm f/2.8 PK Mount Bayonet Prime MF Lens ASAHI Optical - Excellent

Initially, I was very disappointed with this lens- when it arrived it could not mount onto the pk-nex adapter: I soon realized that one of the five screws on the back plate was not correct so I simply took it off and solved the problem... only to realize that it was very soft and even at f8 most of the frame was out of focus- I began to question my understanding of vintage lenses and thought I was asking too much. But after much research I wondered if someone had tampered with the lense and reversed an element: I took off the back and was able to get to the back lens which I turned over. And boy! Was I amazed at the sharpness... corner to corner! A wee bit soft wide open , as with any lens , but one stop up I had an amazing 135mm prime.