LTM Canon 50/1.8 II

[revdocjim]

I got this lens with my newly acquired Bessa R and took it apart to work on the slight clouding. Looking for help online is how I found this forum. There were some very helpful posts in an old thread. Everything went ok and the lens is a good deal clearer now. My only concern is that I may have gotten the rear element turned around. It is really hard to tell which way it goes just by looking at it and I didn't mark it when I took the lens apart. I've read that I'll have soft borders if it is in backwards. Is there any other way of determining if it is backwards or not short of waiting to finish a roll of film and getting it developed?

 

[shimokita]

According to Peter Kitchingman's Canon RF Site there are eight different versions of the Canon LTM 50mm f1.8, while the Canon Camera Museum lists only three versions. The CCMuseum only shows the block diagram for "version I", but it seems that all versions have the same number of elements/groups.... A block diagram should give you a clue about the order of the elements...

Casey

 

[revdocjim]

Thanks Casey. I'm not having any trouble with the order of the elements. Its just that the rear element is almost symmetrical so it is extremely hard to tell the front from the back. I'm afraid that I may have gotten it turned around during disassembly.

 

[ferider]

Had the same issue once with another lens. These days I mark the rear element before removing it.

Since it's an almost symmertrical, double convex element, the only way now is to make sure that it's sharp via test film. Shoot it at f4 and infinity and see if the corners come out OK.

Best,

Roland.

 

[revdocjim]

Well I got developed film back from the lab today and am happy to report that it does not appear that I got the rear element in backwards as there is no noticeable degradation in the corners!!!

 

[ferider]

Very cool. Now you got a clean, super 50mm lens. They don't come much better than this, only more expensive 🙂