Cleaning Canon 100/3.5

[ctdogs]

I am not sure this is the right forum for this question, but what is the best way to open up a silver and black Canon 100/3.5 to lub the aperature?

Thanks in advance.

 

[Scrambler]

I suppose someone who knows what they are doing will come along eventually. Until then, have you tried the grub screws around the aperture ring? It should be just the ring mechanism, not the blades that need cleaning and lubricating if it's an ordinary stiff aperture.

If you haven't already, the lens element just unscrews off the focusing helical and that also reveals the grub screws on the aperture ring.

 

[ctdogs]

stiff aperture on Canon 100.3.5

stiff aperture on Canon 100.3.5

No, I have not tried this. Sounds like a good approach. Do you have any pictures handy showing this?

Thanks

 

[Brian Legge]

The lens head actually screws off without taking out any screws if you haven't made it that far yet. That may be all you need to do as the aperture ring is right there.

 

[ctdogs]

Thanks!

I'll try it this weekend.

best regards,

ctdogs

 

[Scrambler]

Different lens for different camera but same concept except the Canon 100/3.5 doesn't have a set screw holding the lens element in the focus mount:

http://www3.telus.net/public/rpnchbck/Jupiter-8 dismantle.html

 

[mdarnton]

You may want to tread carefully. I loosened the screws on my 90mm Elmar diaphragm ring once because it was stiff and I thought I'dtake it off, clean it out, and loosen it up, and the whole of the insides--all the leaves--dropped out into the middle of the lens. It turned out that the screws went into the ring that both operated the diaphragm and held it all in place......

Anyway, you don't want to lube an aperture--the leaves should be running totally dry. Is it the ring that's sticking? In that case you need to remove it and take off the lubrication that's gotten under it and hardened, most likely. On Canon lenses often unscrewing the head, with the glass, from the focus part will reveal that the aperture ring is held on by a split ring on the back, and you need to watch out that you don't lose the ball bearing that gives click stops (you'll have to take that apart to get the ring off). This should all be clear once you get the head off.

Some heads just screw off, and some are held in by a ring that you have to go in from the back and remove. If it's that, the ring should be larger than the ones that holds the lens elements in, and blockier looking, more obvious. Watch out for shim rings that fine-tune the mount/lens head distance.

All in all, this is the type of stuff I let someone else do. 🙂 You never know what's going to suddenly fall apart that you can't deal with (like my Elmar).

 

[Scrambler]

mdarnton, the aperture ring has grub screws and isn't click-stopped. The head just screws off.

I haven't removed the aperture ring, but i have taken the rear elements out and tried to clean the uncleanable damage within my Canon 100/3.5. :-(

 

[ctdogs]

Thank you!

Thank you!

Thanks to everyone who replied.

Best regards,

Ctdogs