Canon Serenar 35mm f/3.5 Clean, Lubricate, Adjust (CLA)

Pic 1

This Canon Serenar 35mm f/3.5 is in nice condition, but the aperture ring is a little stiff. Plus, I’ve already cleaned the other two so I might as well do the entire set.
I thought this one, being the smallest, would be the easiest. It wasn’t. I had a difficult time reassembling the rear section. For some reason the black painted plate was locking up the helicoid. I eventually got it and the lens works like new. The aperture is now fantastically smooth, partly because it is click-less from the factory.
You can read more about its history in another post.
(follow the images left to right, top to bottom)

10 thoughts on “Canon Serenar 35mm f/3.5 Clean, Lubricate, Adjust (CLA)

  1. When you remove the threaded outer ring and then the inner helicoid, is there a specific way the lens has to be set(i.e. lens focus distance) to re-thread the inner helicoid back on? I was curious if doing it incorrectly would result in the focus being off.


    1. It doesn’t matter how you mount the outer helicoid. It simply screws on around the lens section and is redundant. Also, it’s all thread, so there is no way to adjust the way it mounts.


  2. Cool, thanks. Lastly, if there is a small scratch on the black paint where you would use a spanner wrench is that going to need to be repainted, or is probably fine?


    1. Painting that black part would mostly be for cosmetic reasons. It’s unlikely to have an effect on the optical performance of the lens because it’s 180 degrees from the source of light.


  3. This is a fantastic teardown. I used this today to get to a bad breakout of fungus right by the rear lens, next to the iris blades. The fungus was cleaned up, but the damage to the optical coating is beyond repair. On the plus side, I learned quite a bit in disassembling and reassembling these lenses. Thanks for putting this together

    Liked by 1 person

    1. At the time I was using white lithium grease. It’s not a bad option, but I wish I could get my hands on something more intended for photography. It would be nice to have some lubricant that is slightly thicker. I have some lenses that are too easy to turn and even white lithium isn’t thick enough.


      1. thanks, I will go and get something off ebay, I have this lens just sitting, got it for $5 at the flea market, it needs CLA and should be good to go.I will follow your instructions as guide THANKS A LOT for the step by step disassembly and cleanup

        Liked by 1 person

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