What holds Canon 50mm 1.5 optics module in?

[Brian Legge]

I recently picked up a parts Canon 50mm 1.5 lens as a project.

The lens isn't in great condition - moderate cleaning marks, dirty, etc. Probably not worth the effort but I figure I'd see where I could get with it.

The oddest part is that the optics module isn't secured in the shell. I'm guessing there is a missing retaining ring? I've opened a Canon 35mm 2.8 and Canon 50mm 1.8 before but this lens seems slightly different in design.

Does anyone happen to know how the optics module is held into the shell with this lens?

 

[Pikapig]

i was told that this lens is difficult to open up and put back as a whole. I had one that i wanted to sent it in for CLA..and 2 technicians that i went to, rejected to CLA on this lens for me....one told me that he had done in total 3 pieces of this lens and of which spoiled one of the optics when he tried to assemble after cleaning and its not so commonly found that he cant find another copy to do a change of lens....

This was the last time he ever tried CLA this lens.

I think the 50 f1.9 that remains in the market are in quite terrible shapes....the good one are mostly kept and collected...🙂

 

[Sonnar Brian]

Easy to get the optics module out: it uses a retaining ring that screws in from the back. Once the optics module is out, The rear optics module simply unscrews. I use a split rubber gromet to get it out.

Construction of the 50/1.5 Sonnar formula lens and 50/1.9 collapsible are very different. I cleaned one of the latter a long time ago, and with the understanding that I might not be able to get it back together. Figured it out, not "too bad".

 

[Brian Legge]

Hmm. That must be what I'm missing. The only retaining ring I see in the back is a thin black one which doesn't couple with the rear of the lens shell.

I'll try taking and posting a few photos tomorrow.