Canon 50/1.2: CLA of internal elements possible?

[blakley]

I've looked through Google & the archives here & can't find any information

about the coatings on the internal elements of the Canon 50/1.2 LTM lens -

there's a sample with internal haze I could put my hands on, but I don't know

who could CLA such a beast, nor how likely it would be that the lens would

survive this treatment & still be worth shooting. Opinions?

[back_alley_.]

i took mine apart and cleaned up a bit of haze with 'goo gone'. worked like a charm.

 

http://homepage.mac.com/jlw/photo/canon_disassembly_pix/index.html

 

this might help too.

 

joe

[simon_dai]

I agree with joe, this can all be done by yourself ... there're people selling nice Japanese-made camera repair tool set on ebay for only 50-60 bucks if you don't have one already.

[rjm photo]

Back Alley

 

That's not for the faint-at-heart!!!

[back_alley_.]

the canon was much easier than the 50 summicron i tried to clean.

 

that ended in disaster, complete disaster. but i enjoyed the process and most of the canon lenses that i cleaned turned out ok.

 

btw, those are not my shots of the canon 50/1.4 but from a fellow member at rff.

[feli]

I would send it to Don Goldberg, Focal Point or Golden Touch.

 

It's a nice lens, why take the risk of screwing it up?

 

http://www.lhsa.org/repair.html

[john_shriver]

Cleaning the interior of Canon RF lenses isn't too hard, if you have the right mechanical intuition, tools, and knowledge. Their construction is quite consistent, really. The coatings are hard (unlike Leitz's LTM coatings), so it's hard to mess it up.

 

But, focusing on the 50/1.2 is CRITICAL. It takes some hard to find, and not very practical to make, precision jigs to properly collimate and focus-calibrate the 50/1.2, or to do the same on an LTM camera. You need the 28.80 mm tester for the collimation. You need a 7.5mm jig to set infinity on the rangefinder. Etc. A home camera repair-person just isn't going to have those tools. I've tried making the 28.80 spacer, but I just don't have the precision tools to make one accurate enough. (I don't have a home machine shop.)

 

Indeed, even though I do a lot of my own repairs, my Canon 7s and 50/1.2 are presently at DAG for just that work.

[roger_hicks1]

I had mine mucked out by Optical Instruments (Balham), who despite their name were in Croydon just outside London, last time I checked: not just a glass clean but a mechanical overhaul. It's vastly better than it was but still not very sharp at either maximum or minimum (f/22) aperture. I keep it mainly because it's worth next to nothing and is occasionally interesting to use. It's fine at middling apertures, but then, so is just about anything.

 

I can recommend the company for any kind of work like that; the Ministry of Defence also calls upon them from time to time.

 

Cheers,

 

Roger (www.rogerandfrances.com)

[dan d. chang]

When you disassembling the optical cells you need autocollimator to re-calibrate it. Non- professional can clean it and put back in a lousy way, but hte lens is not up to the original designed spec. to most non-critical shooter, may be ok, but on the test bench this lens will be rated as JUNK. Send to a good professional repair shop if you plan to use it.

[chrisn]

The haze may clean off easily, like Back Alley's (hi Joe!), or it might be something worse. I have one with a damaged element - the doublet just behind the aperture iris is badly etched by fungus. Essex had a go at cleaning/polishing it without success. See the thread on RFF at http://www.rangefinderforum.com/forums/showthread.php?t=10143 for the full details. Several people have recommended sending it to Arax, and that's still on the cards.

 

The bad news is that you can't really tell until you pull the lens apart.