Just pulled the trigger on a Canon 50mm f1.5 in LTM - needs fungus cleaning

peterm1

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For a while I have been considering getting another Canon 50mm f.15. I had one years ago mounted on a Canon IVSB2 but it was in poor physical condition (loss of chrome etc) and I eventually sold it but always regretted losing it given its lovely build quality (weighs a ton) and image potential given its Sonnar design.

So, long story short, one came up at a good price out of Japan in what appears to be excellent physical nick but with some light fungus in the outer regions (damn those hot wet Japanese summers). In any event at least the price was good. I may send it off to my local guy to clean but having worked on a few lenses now and then I am happy to give it a light clean myself if the task is not altogether too demanding. I wonder if anyone here has experience of working on this lens and can offer advice based on experience.

I understand that it is usual to come in from the rear (no jokes please) by unscrewing the rear slotted ring which allows removal of the optical block but I am unsure where to go from here although it may be obvious once inside. Clearly I need to open the group that has the fungus and give it a good clean. Sandblasting should do it (JOKE!)

Any serious advice from anyone who has worked on this lens would be nice (trial and error is OK but I prefer less error if I can by calling on the experience of others).

This will be one of several Canon 50s I hold. So far I have the 50mm 1.8 in chrome, the same in black and chrome, the 50mm f1.4 also in black and chrome and the 50mm f1.2 (but optically a bit wretched - tho' it still renders nicely in good conditions). And of course I also have divers Leica and Voigtlanders in 50mm plus a Jupiter 8 50mm f2 which is of course also a Sonnar design like the Canon 50mm f1.5. I like the crisp rendering of Double Gauss lenses but I love those damn Sonnars.
 
My memory might be going; but I'm almost sure Johan at Johanniels.com has done a great piece on how to do this lens.
 
Peter, you in Adelaide?
Try this guy, forgot his name, i'll post it later when i find his card. Repaired a Nikon FM2N for me. Old fella knows his stuff around all cameras and lenses.
Eden Photographic Repairs ph: 0403 008 911
 
Peter, you in Adelaide?
Try this guy, forgot his name, i'll post it later when i find his card. Repaired a Nikon FM2N for me. Old fella knows his stuff around all cameras and lenses.
Eden Photographic Repairs ph: 0403 008 911


Yes I am in Adelaide. That sound like Charles Bridgewood. Charles did some work for me 15 years ago but I moved interstate (later came back) and lost contact with him. I was not sure he was even still around. Thanks for the contact number. Regards Peter

Edit:Just a thought. There used to also be a camera store called Eden Photographic in Adelaide years ago but it closed as a shop front. Its possible that someone connected with that outfit is doing repairs in Adelaide but I did not know about it. The existing shop fronts keep their repair guys' names a deep secret as they are afraid customers will deal direct and cut them out. Which of course is exactly what I would do.
 
Peter
Johan has over 7000 posts and is a well known member here. Like I said; I'm almost sure he wrote about the Canon 50. www.johanniels.com
Hope I got it right for you?

Thanks again. It worked that time. I think I must have been having problems with my Internet connection. I will search his site. cheers Peter
 
I had saved his write-up, and it was well done, as I have this lens to for my Canon 7sz, but a while back Mozalla did an update and lost all my older stored fav's. Talk about the internet?? Peter, I did find it on his site on the 50 1.2, and it is with excellent pictures and easy write up to follow.
 
I picked up a Canon 50/1.5 a few months ago that has some internal cleaning marks. I took it partially apart to see if if I could clean it. It’s an easy lens to take apart. I came in from the back. I forgot the exact procedure but there’s nothing complicated involved. Just remove a retaining ring or two and unscrew the rear elements. You can easily get the lens apart to the aperture blades.

Jim B.
 
Yeah, it's simple and fairly straightforward. One plus of the Sonnar design is relatively few groups, so there isn't much that can get confused on reassembly. One thing to note is that I have seen samples of this lens with the beginnings of separation in the big rear group, just around the edges. Could be mistaken for fungus before disassembly. It also had no visible effect of images, so it's not really anything to worry about.
 
Yeah, it's simple and fairly straightforward. One plus of the Sonnar design is relatively few groups, so there isn't much that can get confused on reassembly. One thing to note is that I have seen samples of this lens with the beginnings of separation in the big rear group, just around the edges. Could be mistaken for fungus before disassembly. It also had no visible effect of images, so it's not really anything to worry about.

I am pretty sure it is fungus - certainly looks more like it to me than any separation I have seen.

1600%E3%82%B5%E3%82%A4%E3%82%BADSC_0198.jpg
 
it's very difficult to get lighting right so as to photograph lens defects.

Speaking of Canon 50/1.5, I picked this one up for not much $ and decided to send it off for some customizing which is almost completed. Glass had a sliver of haze on the very edge which cleaned up. As stated above, these lenses are easy to work on.

And they are my favorite formula - sonnar. :)

bpiiif.jpg
 
it's very difficult to get lighting right so as to photograph lens defects.

Speaking of Canon 50/1.5, I picked this one up for not much $ and decided to send it off for some customizing which is almost completed. Glass had a sliver of haze on the very edge which cleaned up. As stated above, these lenses are easy to work on.

And they are my favorite formula - sonnar. :)

bpiiif.jpg


I agree - my favorite design too. And by the way that is one pretty lens on your camera. Have you tried it yet?

But back to Sonnars in general. I have also recently been picking up a few more longer lenses mainly in the 105mm to 135mm range with Sonnar designs, most being quite common and pretty cheap for the most part. Many though have been slowly accumulated over 25 years or so. I have several including the famous Nikkor 105mm f2.5 (early), the Nikkor 135mm f3.5 (early), a "Force" 135mm f3.5 (re-badged from the Komura / Super Acall to which it is identical in design and build) and a Titar 135mm f3.5 in M42 - a "no name" lens of the 1960s - 1970s. And I also have quite a few Takumars which are apparently of this design (I have not seen the optical diagrams) - the 85mm f1.8, 105mm f2.8, 135mm f3.5 (various models of the latter two). And of course the Jupiter 9 85mm f/2 and Jupiter 8 50mm f/2. I am feeding my habit.

Only recently it suddenly dawned on me just how ubiquitous this lens design was back in the day. This was previously the subject of a thread here. https://www.rangefinderforum.com/forums/showthread.php?t=69170&page=7
 

Yes that is entirely possible. But haze is normally even more easy to clean than fungus which can as I am sure you know sometimes cause etching. I have certainly had to deal with it before in Leica glass. In this case, the price was good for a much sought after lens in good physical condition - only $160 US so I decided to chance it. But I did think very carefully about it and figured that if push came to shove and I decided to have it professionally CLA'd it would work out no more expensive than one in top condition.

The exterior body.

1600%E3%82%B5%E3%82%A4%E3%82%BADSC_0185.jpg


Rear elements look clean

1600%E3%82%B5%E3%82%A4%E3%82%BADSC_0190.jpg
 
Whether haze or Fungus, if it's confined to the edges it may not effect the image making ability.
All of these 50mm Canon LTM lenses are easy to open.
Good Luck Peter. That 1.5/50mm is a lens I would like to try some day.
 
I mentioned in a previous post that I recently picked up a Canon 50/1.5 that had internal cleaning marks. Try as I may to “clean away the cleaning marks,” they’re there for good. I’m amazed on what little effect they have on image quality. I figured there’d be a slight loss of contrast or perhaps a bit of softness. None that I can tell. If your lens does have haze, and it’s confined to the edges, it may not affect image quality at all.

Here’s a pic from a lens test I shot back in September. 50/1.5 at F2.8 (or F2.0, my notes are unclear).

Kayla1.jpg


Jim B.
 
I mentioned in a previous post that I recently picked up a Canon 50/1.5 that had internal cleaning marks. Try as I may to “clean away the cleaning marks,” they’re there for good. I’m amazed on what little effect they have on image quality. I figured there’d be a slight loss of contrast or perhaps a bit of softness. None that I can tell. If your lens does have haze, and it’s confined to the edges, it may not affect image quality at all.

Here’s a pic from a lens test I shot back in September. 50/1.5 at F2.8 (or F2.0, my notes are unclear).

Jim B.


Yes I agree. and that's a very nice shot by the way. I have had similar experiences. A few years ago I bought a Canon 50mm f1.2 with bad cleaning marks on the front element's coating. I feared that it would be likely to have severely compromised performance but found that in many situations at least, it performs very well (though pretty low in contrast - something that does not bother me as it can actually be a benefit). As long as there is no back lighting and lighting is fairly moderate and even over all it turns in nice shots. A couple of examples appear below, which serve to illustrate its typical rendering.


Those Eyes - Color by Life in Shadows, on Flickr

Market Cafe Brunch by Life in Shadows, on Flickr
 
Well it has arrived. I am impressed by Japanese sellers . Seven days on the button to get to Oz. I have experienced that organisation and good service with other Japanese sellers. No wonder I like them. What's more, the lens looks much much cleaner than shown in the eBay advert. The seller made it sound (and somehow look) somewhat worse than it actually is. There is a smudge of something on an inner element (I have not yet studied it closely but will soon) but its pretty minimal - so I may defer any thoughts of stripping down and cleaning for now. A couple of quick close shots at home indicate that this is just like a Sonnar should be - sharpish in the centre rolling off into unsharpness in that delightful "Sonnarish" way that not enough modern lenses have. Fun times ahead.

PS I had remembered that this is a dense lens but had forgotten just how physically small it is. It is more or less about the size of (but much heavier than) that other Sonnar, the Jupiter 8 (also a copy of the Zeiss original). Physically both are similar in size to the Canon 50mm f1.8 but shorter overall than the Leica Summarit.
 
I agree - my favorite design too. And by the way that is one pretty lens on your camera. Have you tried it yet?

Not yet, it will be here in a week or so.

But back to Sonnars in general. I have also recently been picking up a few more longer lenses mainly in the 105mm to 135mm range with Sonnar designs, most being quite common and pretty cheap for the most part. Many though have been slowly accumulated over 25 years or so. I have several including the famous Nikkor 105mm f2.5 (early), the Nikkor 135mm f3.5 (early), a "Force" 135mm f3.5 (re-badged from the Komura / Super Acall to which it is identical in design and build) and a Titar 135mm f3.5 in M42 - a "no name" lens of the 1960s - 1970s. And I also have quite a few Takumars which are apparently of this design (I have not seen the optical diagrams) - the 85mm f1.8, 105mm f2.8, 135mm f3.5 (various models of the latter two). And of course the Jupiter 9 85mm f/2 and Jupiter 8 50mm f/2. I am feeding my habit.

Some of my favorite Sonnars are the 90/2.8 Contax G, the 85/2.8 C/Y, and the early 105/2.5 Nikkor. Also the 100/2.8 Contax N which is fabulous, maybe the best of all the short teles, but big and heavy.
 
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