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Artisticwoods
Tinkerer
Username: Artisticwoods
Post Number: 1
Registered: 03-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 29, 2009 - 12:11 am: | 
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Hi,
I purchased a Canon 300mm lens FD, and the aperture ring is not working. I would like to try and repair it, but am leery about this, as I have heard that there are ball bearings in that area. I don't have a manual for repairing the lens and don't know if one is available. Any help would be greatly appreciated. Thank you, Richard |
Glenn
Tinkerer
Username: Glenn
Post Number: 538
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 30, 2009 - 05:27 pm: |
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Richard,
The Canon lens repair manuals are somewhat complicated, there is a general manual that is written round the standard lens. Then there are some detailed adjustment notes for each type of lens - wide angle, tele and zooms accompanied by what are basically exploded parts diagrams for each lens.
Apart from the odd detent ball, the ball bearings are only associated with FDn lenses fitted with the 1.4 Type Mount - this mount first appeared on the f1.4 50mm and the rear projecting operating levers run on ball races. The other mount is the 1.8 Type - as fitted to the FDn f1.8 50mm, the levers just run in grooves in the rear mount. The 1.4 mount is fitted to most tele lenses and the more expensive offerings in the other focal lengths, the rather crude 1.8 type has very limited use.
The good news is that you can remove the inner part of the mount as a complete unit. Remove the 3 radial screws that retain the stainless steel bayonet ring in the rear of the lens - these screws are tight, use a well fitting screwdriver and do not wreck the screw-heads! Pull/lever out the bayonet ring and then lift out the inner part of the mount (with the levers) as a complete unit. Do not split the two halves of the removed inner unit - you will be hunting for approx 100 steel balls!!
Which 300mm lens is this? I will have to dig my manuals out, so give me a couple of days. The problem is that the 'manuals' are really just an 'aid memoir' for a trained technician, so the exploded diagrams are somewhat misleading sometimes. Send me a PM if you need further help and I will get back to you. |
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