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Message |
    
Flashinm
Tinkerer
Username: Flashinm
Post Number: 8
Registered: 10-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 25, 2012 - 12:15 pm: | 
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I have both of these lenses with oil on the aperture. I started on the 50mm from the mount. I got the helicoid separated, but I still can't get to the aperture block. The front ID ring seems to spin freely, but doesn't unscrew. Does anyone know how it comes off? The ID ring on the 24mm isn't budging, but rather than force it I thought I'd check to see if it's supposed to unscrew. Anyone know how these two ID rings are supposed to come off? Thanks. |
Flashinm
Tinkerer
Username: Flashinm
Post Number: 9
Registered: 10-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 25, 2012 - 12:46 pm: |
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Got the 50mm figured out. The ID ring pops off. I used a small flathead screwdriver wrapped with a pec pad with gentle upward pressure to pop it off and got to the aperture mechanism. Anyone know about the 24mm? |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1244
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 25, 2012 - 08:26 pm: |
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I have disassembly notes for the 50/1.8; I think these will all be similar. The ID ring was stuck down with a spot of glue, which apparently has come loose on your 50mm but not on your 24. I pried the ring off from the inboard side. |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 225
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 28, 2012 - 06:23 pm: |
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Hey Rick, I've got a couple follow up questions to your comments. You mention you think they will "all be similar." So, is it safe to assume then that most, if not all, of the small nFD lenses (excluding zooms and long teles, I'm assuming here) have ID rings that are fixed with small drops of glue? And what sort of glue do you like to use when reattaching the ring? Maybe Locktite Blue or do you prefer something more permanent? |
Glenn
Tinkerer
Username: Glenn
Post Number: 1045
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 29, 2012 - 12:00 pm: |
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No it is not safe to assume that all nFD of below a certain focal length follow the 50mm/f1.8. The 50/1.8 is a particularly nasty example of cost cutting, particularly in the aperture operating and sender mechanism. Plastic rings are always glued in - a couple of spots of contact adhesive does the job - metal rings on the large max aperture short focal length lenses are screwed in. However you should note that my examples are all early production examples, I have no idea what Canon did to lens construction when the cost cutting really started to bite. If the A1 camera is anything to go by, large amounts of machined metal components were substituted with molded plastic. Get hold of the proper Canon service documents, it is all listed there in. |
