Just got one of these beauties on eBay. I shot several shots with it with no problem. All of a sudden when I change the aperture the lens does not stop down. I took it off the camera and removed the (MD-NEX Adapter) and the blades will not open and close - they stay fully open. Any ideas what may cause this? Faulty lens? Faulty user?
Sounds like a stuck aperture mechanism, it is relative easy to take the Rokkor apart and clean the mechanism but if you don't trust yourself then either take it to the shop or email the seller, hard to believe that the seller didn't know about this.
I've cleaned mine twice (completely, each aperture blade individually) and re-greased helicoid... and it came back. I think I am just unlucky, or something... cleaning the blades is pretty simple as long as there isn't oil leaked EVERYWHERE.
brockwhittaker wrote:
Are you using a converter for EOS? Sometimes on the mount if it is locked/unlocked, it differs on whether or not you can change the aperture.
No sir - using it with a NEX-7. I have an MD to NEX adapter..... the aperture won't change even if the adapter is off.
