Hi! Some time ago, which unfortunately, I cannot pinpoint with any accuracy, my F 85/2.8 has developed a very strange problem. Most recently it has manifested again on my *istD, and finally it forced me to seek for help.
The problem is with infinity focus. By the way, yes, this lens allows autofocus, and it works, both on *istD, and on MZ-6. So, the problem is like this. When pointed to infinity the lens would come to focus mechanically. So I would see that whatever I am shooting is in focus. The motor would stop, so the AF stops hunting. However, focus confirmation indicator would start blinking, as if the lens cannot be brought to focus. Furthermore, in *istD, the center AF indicator would blink in read, as if it sees the focus. Ultimately, I wouldn't be able to release the shutter because AF confirmation does not confirm. I tried different apertures from f/2.8 to f/5.6 (the range where aperture is fully mechanic). Same outcome. If I try to focus just a tad closer than infinity - voila - proper focus, nothing fancy. The first time I encountered this, I cleaned up AF coupling of my MZ-6. But *istD seems to have stronger motor and its AF coupling is clean. What gives? What to do? One of the main reasons that I bought this lens was indeed AF. To focus manually soft focus lens is beyond my eye-vision :(. Thanks in advance. -- Boris
