View Full Version : Can't focus with Opton Oberkochen f/4.5 150 mm lens (due to missing rear element?)

Magne G.
13-Jun-2019, 02:51
I am unable to focus on anything with a Opton Oberkochen f/4.5 150 mm lens whereas I have no problems with another 150 mm lens. I noticed the Opton has no elements behind the shutter (see the picture). Is that the reason?

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Assuming that is the explanation, is there a fix? I guess such rear elements are not simply laying around (except the ones that fell of this lens, ha ha). Will the lens be of use to anyone else? (The Copal shutter isn't working properly either; the lens was used with a Sinar shutter).

Dan Fromm
13-Jun-2019, 04:51
No fix. The lens is a Tessar. Tessar front cells can't form images. If the seller can't supply the lens' rear cell, send it back. If you misplaced the rear cell, look for it.