Canon LTM Can this be cleaned? Canon 50mm f1.5

Canon M39 M39 screw mount bodies/lenses
It does not look like fungus to me but photos sometimes lie. Especially photos posted by sellers. :^) It is hard to say what it is though but it looks bad. Short of physical damage in the way of etching or scratches my experience is that most lenses can be cleaned. But sometimes there are residual issues like damage to coating that cant be repaired so the question is always is it worth it. Usually it depends upon how cheaply you can get it for. If you are willing to gamble keep your bid low. Here in Australia the cost of a CLA is between $100 and $200 and that is the discount you would need to require. Others will no doubt have a view on what the problem is. Also if you can communicate with the seller ask a few questions. The damage shown looks almost like immersion damage which would result in internal corrosion and similar problems with all elements. I would ask if the lens focuses freely and the aperture functions normally etc.

PS fungus normally looks more like this. But as I say images can be deceptive.

ReallyBadFungus.jpg
 
Thanks Peter, I will ask those questions. Yes it looks bad. Do you know if Canon 50 f1.5 is easy to disassemble like 50 f1.2?

The current bid is 75 USD with a canon body but there is huge shipping cost to my country, around 65 USD.
 
LeicaFoReVer said:
Thanks Peter, I will ask those questions. Yes it looks bad. Do you know if Canon 50 f1.5 is easy to disassemble like 50 f1.2?

The current bid is 75 USD with a canon body but there is huge shipping cost to my country, around 65 USD.
Click to expand...

I am afraid I do not know if this one is easy to disassemble (in my experience lenses are often easy to disassemble - but are always hard to reassemble correctly for all but skilled technicians). As you say the 50mm f1.2 is however an exception.

I bought a Canon 50mm f1.5 from Japan a short while back and like many lenses from that country, which has hot wet summers, it was advertised as requiring a clean as it has some fungus. But in my case I was lucky. The price was not too bad and the lens in fact, while potentially needing cleaning and servicing at some time, is perfectly usable as it is for now. So I will not worry about it until I must.

You might be better looking for a lens in this condition - good but not perfect, like mine from Japan. (This lens seems to become available from Japan quite often - more often than in other countries - which I guess is understandable given it is a Japanese made lens) And the Japanese sellers seem to be fairly trustworthy in their descriptions in my experience. You will pay more but you will be sure of what you are getting. Their postage and handling charges tend to be fair too.
 
It looks like dried balsam from separation, which is probably worse than fungus. PeterM's advice is sensible in going for a lens that is usable for now.
 
I can’t get your link to work, so I have not seen the picture, but I would advise caution with old Canon 50mm lenses. They are very often found with damage to the element behind the diaphragm caused by etching of the coating and eventually the glass. This cannot be repaired without repolishing and recoating the element, which generally costs more than the the lens is worth. I have heard a few theories about the cause. For some reason, the black 1.8’s seem to be the worst offenders. In any case, I would avoid lenses that appear to have haze on this surface.
The 1.5 is very easy to disassemble.

Cheers,
Dez
 
I can see the pic now, and it looks like the etching problem. I would not buy this lens.

Cheers,
Dez
 
Haze (or in a serious case, corrosion) of the glass. Very common with the 50/1.5 on the element just behind the aperture blades. Yamazaki-san of Yamazaki Optics in Tokyo told me not to bother getting Canon LTM lenses cleaned because the haze would just come back anyway. He said whatever Canon used in the glass to create the desired refractive index for that element is the problem as it corrodes.
 
That rear element is very simple to pop out, and yes, it can be cleaned, but the question is always how will it look after it's cleaned? If I had it in front of me I could make a better guess, but just from that one pic, and not knowing if that is etched into the glass or not, I would pass too. Good decision to move on.
 
Hmm, tempting. The body is worth of 100 bucks. If I will be the only one bidding, I would be risking only 35$. I might take a chance. I will keep you posted.
 
A few months back a guy was selling a Canon 50/1.5 on AGUG for a ridiculously low price. It had “internal cleaning marks.” I figured, what the hey, at that price, it’s worth a gamble, so I bought it. I received the lens and it, indeed, had internal cleaning marks. I took it apart (easy) and tried to re-clean, but couldn’t, the marks were on the coatings.

If there’s any impact on overall image quality, I can’t tell. Images to my eye are sharp and contrasty (as well as can be expected from a Sonnar-design).

Up to you if you want to gamble on this lens or not, but it may be worth considering.

Jim B.
 
don't know what exactly it is but from little experience with Canon LTMs I'd say it's a "hard" change of the glass surface as e.g. corroded coatings that cannot simply be wiped away, and that there would be some, not much impact on image quality. ( same amount of damage on a front lens would not have, or harldy would have any impact )
 
You made the right decision to skip that auction - I think the optics have had it!

However,for future reference, the Canon 50/1.2 is easy to disassemble: https://www.johanniels.com/index.ph...anon-diy-cleaning-a-1-2-50mm-rangefinder-lens

I bought one a few years ago that had balsam separation, covering an eighth of the front elements - it looked like you expect: part of the lens was discoloured, resembling a crescent moon. The lens was cheap, so I repaired it myself: a website said heating it gradually in an oven to soften the balsam often works. I removed the lens block, put it on a baking tray and built a support around it using stones, to prevent the top element possibly sliding once heated. After cooling overnight, the lens was perfect!

I can’t recall the website but I’m sure Google will tell you. The website mentioned the temperature/gas setting to use - the aim is to soften and just melt the balsam using the lowest temperature, not to fry the lens!
 
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