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Canon Serenar f1.8, 50mm LTM lens

This Serenar 50/1.8 came as a body cap on a Canon IVSB2 acquired at a camera show in late '97. It had dust specs, haze, front element cleaning marks and fine scratches. The result from a trial roll was discouraging. I could not find the proper 50mm lens in the ensuing camera shows, instead  I ended up with a minty  Serenar 35/2.8 with matching view finder in its original leather case.

 After shooting a few more rolls, a cousin became really interested in this Canon RF system. Since I was contemplating the purchase of a used Leica M6, I sold the lot with a right of first refusal clause if he decides to unload at a later date. He enjoyed it for several years using an Elmar E39 50/2.8 LTM and the Serenar 35/2.8.

Fast forward to last December, he was trimming down his RF collection and I got the outfit back. Meanwhile  I've read many good things about this Planar design at Rangefinder forum and Dante Stella considers it at par with the original Leitz rigid Summicron.

My curiosity was piqued and searched for information on how I can get rid of the dust specks and haze. I found a post at Rangefinder forum  (can't find the exact link) describing disassembly which starts at the rear retaining ring...

The whole optical module comes off the focusing helical

Be careful not to scratch the glass...

Fortunately the middle lens element was within the torque ability of my heavy duty tweezers ;)

The aperture blades were dry and the click stops turning smoothly, just cleaned out dirt and sparingly relubed with lithium grease.

I discovered edge separation in the cemented pair middle lens element, not very encouraging...

Everything cleaned and lubed. 

Ready for a test drive...

Bessa R
Acros 100/Diafine
Bessa R
Acros 100/Diafine
Leica M3 + M adapter
Shot @ f1.8...not too worried about the balsam separation ;)

More Serenar 50/1.8 pics


  1. Thanks for review, it was excellent and very informative.
    as a first time visitor to your blog I am very impressed.
    thank you :)

    1. Thanks for the kind words!


  2. Good review of how to clean a canon/serenar 1.8 rf lens. these lenses are remarkable and generally unappreciated by Leica men

    1. Thanks, Canon LTM lenses are excellent performers!

  3. Dear Joseph,
    I was lucky to find you here in your blog. I just followed your instruction to clean a Canon Serena 50mm (1.8) lens - just like the one you have here. I followed all the steps carefully, but there's one step that I was careless - the 'side' of the most rear lens element. I did took a picture of the rear lens section, but it does not provide the information I need. Upon careful inspection, the rear lens looks very symmetric, but has black paint job done along the edge of the lens. Now, if you look closer, the edge part is not symmetry - one side of the lens is pretty flat while the other side has black paint covered over the side of the lens. You have to look at it very closely to see this.

    My question: do you happen to know which side of the lens faces the back of the lens? Again, do you have the clean side or the painted-edge side face forward?

    Thanks for your great work and support. If you don't know the answer, that's fine. I will have to try the lens both ways, and see if I can spot any differences. I have a feeling that I may not able to tell due to the Gaussian design.

    1. Hi Jae Lee,

      Unfortunately I did not take note of the last lens element's orientation. Please post again once you've found clues on the proper orientation to benefit other readers.



    2. There's a block diagram shown here at the Canon Lens Museum. Which is only shown for the chrome models.

      They don't even have my Canon 50/1.8 (Type 6) listed, which is basically the Serenar optics, but with the newer alloy body (black grip).

      The newer body is easier in the sense that there's a tiny screw just past the aperture ring, that if you loosen (doesn't have to be removed completely) the front portion unscrews, and then you can clean behind the front element and the front of the middle element.

      Though I need to get a spanner and get at the middle of the middle and rear element.


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