Canon LTM Potential Lens Issue - 50mm f/1.8

[ryeryeguyguy]

Hi all. So after my post about whether to choose a Contax ii or a Canon L1 (I received a beautiful Contax ii that I can't wait to shoot), a friend went to an estate sale this weekend and happened upon a Canon LTM lens - the 50mm f/1.8. They bought it for me as a surprise thinking I was getting a Canon LTM camera, which was amazingly kind. They spent $70 on it. As I don't have a lot of excess money lying around, that counts as a decent chunk of change for me. I don't have an LTM camera at the moment, but hope to one day. The lens is free of haze and fungus, but there is this little black bit sticking out that you can see wide open, both from the front element and back element. When closed down you can see it behind the aperture blades.

Question is, do you feel this will affect shots or not? I mean it must, right? I reached out to someone that is known to repair Canon rangefinders that I won't name, and they assure me they do not believe it will affect photos. I wanted to ask the group here, however, and get a consensus and an understanding of why the repair person thinks it won't just for my own edification as part of my education in rangefinders and their associated lenses. I also want to know if it's usable without expensive repair come the time I am fortunate enough to afford a camera that takes LTM lenses.

Thanks in advance!

 

[punkzter]

I could easily be wrong, but I would imagine that this would have an impact on image quality at higher apertures. Check out this link which sort of applies.

If that lens truly doesn't have any haze (you did a flashlight test on it?), then it is worth getting repaired. It's a great little lens and they are somewhat uncommon to find without a haze that cannot be removed. You'll probably need to spend $70-$100 for a full CLA.

 

[ryeryeguyguy]

It truly doesn't have any haze. Doesn't have any fungus. Completely haze and fungus free. So I feel lucky about that, because I've read how rare that is. But it does have this secret third thing haha.

 

[ryeryeguyguy]

I should add that it's not on the element, it's riiiight behind the aperture blades but doesn't move at all when I move the aperture blades. And all aperture blades seem to be moving freely and are accounted for when moving, so it doesn't seem like a stuck blade?

Edit: I should also add that I absolutely am not confident or experienced enough to open it up and try and fix it myself. Haha. That's a no go.

 

[Miles.]

What you are seeing is the paint around the edge of the front doublet flaking off. It’s very common on this lens, and many other lenses of this era. The paint is used to reduce reflections, and theoretically increase contrast.

Fortunately for you it’s an incredibly easy (beginner friendly, I promise!) fix. On this lens you’ll need to unscrew the front name ring and front optical block (rubber lens “wrenches” work great, and are cheap), and then slowly lift out the front optic (a lens sucker is ideal, and also affordable). The flaky paint chip can now be removed with a pair of tweezers.

You can also remove the rest of the paint that will eventually flake off and reapply a water-soluble matte black paint, or just a sharpie would be fine.

 

[ryeryeguyguy]

What you are seeing is the paint around the edge of the front doublet flaking off. It’s very common on this lens, and many other lenses of this era. The paint is used to reduce reflections, and theoretically increase contrast.

Fortunately for you it’s an incredibly easy (beginner friendly, I promise!) fix. On this lens you’ll need to unscrew the front name ring (rubber lens “wrenches” work great, and are cheap), and then slowly lift out the front optic (a lens sucker is ideal, and also affordable). The flaky paint can now be removed with a pair of tweezers.

You can also remove the rest of the paint that will eventually flake off and reapply a water-soluble matte black paint, or just a sharpie would be fine.

Thank you Miles! I appreciate it! I will give this a try. Mind if I ask a few questions when it comes time for the lens' operation? Haha.

 

[Miles.]

Thank you Miles! I appreciate it! I will give this a try. Mind if I ask a few questions when it comes time for the lens' operation? Haha.

Happy to help.

Good luck and have fun!

 

[ryeryeguyguy]

Happy to help.

Good luck and have fun!

Thank you!

 

[peterm1]

What you are seeing is the paint around the edge of the front doublet flaking off. It’s very common on this lens, and many other lenses of this era. The paint is used to reduce reflections, and theoretically increase contrast.

Fortunately for you it’s an incredibly easy (beginner friendly, I promise!) fix. On this lens you’ll need to unscrew the front name ring (rubber lens “wrenches” work great, and are cheap), and then slowly lift out the front optic (a lens sucker is ideal, and also affordable). The flaky paint chip can now be removed with a pair of tweezers.

You can also remove the rest of the paint that will eventually flake off and reapply a water-soluble matte black paint, or just a sharpie would be fine.

This was my inclination too. Having said that I usually see peeling internal paint resulting in smaller less defined pieces than this relatively large piece. But it's still a good bet. I am not convinced it's at the front of the lens though. Both your testimony and the photo suggest it is behind the aperture iris. Which suggests coming in from the back of the lens!

In any event I suggest that you enter this search term into Google. "Canon 50mm 1.8 ltm disassembly" It will bring up several video tutorials on how to open this lens body either to clean the lens elements or for other purposes. There are a few versions of this lens but all except the last version (which is easy to identify from its very different, more modern body style) should be basically similar so look for a video with your style of 50mm f1.8 for guidance.

Getting lens elements out is relatively simple but is still daunting for a newbie and you need correct tools (the videos will help here). Also there are 5-6 internal elements (I cannot recall specifically for this lens) and it goes without saying that each one has to go back in exactly the correct place and orientation. So even though you may need to remove only a couple of these to get at the offending intrusion inside, make careful notes (many people use photos) and work consistently and systematically to lay each piece you remove in a line from left to right or right to left. Then when closing it up work back in the opposite direction. But be consistent in placing each element you remove either forward face up or forward face down - then remember which one you are using so you do not mess up when reinstalling. If your problem is indeed peeling black internal barrel paint, then when it's removed it will leave a shiny spot on the interior of the lens barrel which may result in some flares in future shots. It pays to buy a small pot of black matt paint and re paint it. A modelers shop is a good source of such paint and the tiny brushes needed). BTW it pays to lay a small piece of light colored cloth on the table or work bench you are using so that if you drop anything it will not bounce off the table and disappear onto the floor. I have spent literally hours searching for small parts such as screws when they drop to the floor and bounce or roll under a fridge or something. 😉

 

[ryeryeguyguy]

This was my inclination too. Having said that I usually see peeling internal paint resulting in smaller less defined pieces than this relatively large piece. But it's still a good bet. I am not convinced it's at the front of the lens though. Both your testimony and the photo suggest it is behind the aperture iris. Which suggests coming in from the back of the lens!

In any event I suggest that you enter this search term into Google. "Canon 50mm 1.8 ltm disassembly" It will bring up several video tutorials on how to open this lens body either to clean the lens elements or for other purposes. There are a few versions of this lens but all except the last version (which is easy to identify from its very different, more modern body style) should be basically similar so look for a video with your style of 50mm f1.8 for guidance.

Getting lens elements out is relatively simple but is still daunting for a newbie and you need correct tools (the videos will help here). Also there are 5-6 internal elements (I cannot recall specifically for this lens) and it goes without saying that each one has to go back in exactly the correct place and orientation. So even though you may need to remove only a couple of these to get at the offending intrusion inside, make careful notes (many people use photos) and work consistently and systematically to lay each piece you remove in a line from left to right or right to left. Then when closing it up work back in the opposite direction. But be consistent in placing each element you remove either forward face up or forward face down - then remember which one you are using so you do not mess up when reinstalling. If your problem is indeed peeling black internal barrel paint, then when it's removed it will leave a shiny spot on the interior of the lens barrel which may result in some flares in future shots. It pays to buy a small pot of black matt paint and re paint it. A modelers shop is a good source of such paint and the tiny brushes needed). BTW it pays to lay a small piece of light colored cloth on the table or work bench you are using so that if you drop anything it will not bounce off the table and disappear onto the floor. I have spent literally hours searching for small parts such as screws when they drop to the floor and bounce or roll under a fridge or something. 😉

Thank you. Very helpful advice. Though now I am much more disinclined to open it up myself.

 

[Miles.]

@peterm1 brings up a lot of great points when it comes to beginner camera repair, but in this specific case there is no adjustment in the front optic that you need to worry about getting back in the right position, nor do you have to separate the front doublet from the front element to address the flaking element paint.

 

[julio1fer]

It should not have any noticeable effect on image quality.

 

[ryeryeguyguy]

@peterm1 brings up a lot of great points when it comes to beginner camera repair, but in this specific case there is no adjustment in the front optic that you need to worry about getting back in the right position, nor do you have to separate the front doublet from the front element to address the flaking element paint.

The paint definitely is behind the aperture blades when I close then down. I can see it through the rear element. Does that change your ass? Obviously you know the internal makeup of this lens better than I! Haha.

 

[Miles.]

The paint definitely is behind the aperture blades when I close then down. I can see it through the rear element. Does that change your ass? Obviously you know the internal makeup of this lens better than I! Haha.

No. It will either come out if you turn the lens upside down (with the aperture set at 1.8), or you will have to very gently grab it with tweezers.

 

[ryeryeguyguy]

No. It will either come out if you turn the lens upside down (with the aperture set at 1.8), or you will have to very gently grab it with tweezers.

Perfect. Thank you!

 

[Steve Goldstein]

@peterm1 said

In any event I suggest that you enter this search term into Google. "Canon 50mm 1.8 ltm disassembly"

You can remove all the hits resulting from more modern EF lenses by slightly modifying his suggested search to
"Canon 50mm 1.8 ltm disassembly -ef". And don't include the beginning and ending quotes in the search term.