Lens Repair Advice

Mephiloco

Well-known
Local time
10:29 AM
Joined
Apr 26, 2009
Messages
515
I just recently acquired a Canon 85/1.9 from the classifieds. The focus was stiff so I lubed it up and got it working better, aperture ring was stiff so I cleaned out the rust and lubed that as well. Anyways, I've shot maybe 3 pictures on it, grabbed it from my bag today to see this

4120528134_39a9c3ffc0.jpg


I never did anything with the elements, I'm guessing it happened when I tossed the lens into my padded bag or something. There were flakes in the lens from the aperture blades when I first got it (looked like paint chips) but the blades were (and still are) intact.

Anyways, I sent an email to DAG for a quote but was wondering if there was somewhere else to send it (ie faster and/or cheaper). I've never dealt with Youxin Ye, and I'm not sure if he does lenses. In short, the optics are perfect, the focus is usable, but these damned aperture blades are messed up and I'd rather not pay as much for the repair as I did for the lens in the first place.

I thought about trying to fix it myself, but figured if I messed up the lens would be shot (or be stuck with a 1.9 aperture).
 
Youxin does not work on Canon lenses to my knowledge. He will not work on Canon Bodies.

I hate when that happens- I had the same thing happen with a Komura 135/3.5.

Sad part- the repair is likely going to be more than the lens is worth. My Canon 85/2 was ~$100. The glass was hazed over, and black paint flakes inside. It cleaned up well.
 
The optics are fine, the only thing wrong is the aperture blades. I like the lens (from the 2 or 3 shots I've gotten out of it) but for $100 I don't know if it'll be worth it.
 
probably because you lubed aperture ring. the lube found its way to aperture blades.
You never want to lube aperture blades. They'll stick together if you do.
 
You're talking about hte out-of-roundness of the aperture, not just the residual oil... right? As others have said, lubing them was the unfortunate mistake. It might be salvagable by tearing it down, cleaning the aperture blades and ring thoroughly, and correctly replacing hte blades -- or not. It is possible that it is broken.
 
I didn't lube the blade, just the focusing helicoil. There is no oil at all on the blades, I put some tacky oil on a rag and rubbed it on the aperture ring since it wouldn't move past 2.8. Used wheel bearing grease (which does not move, at all). I'm just assuming it messed up due to a fault of my own, but I'd like to get it fixed.

I'm waiting for DAG to get back to me since the last time I had him do a lens he had to fix an aperture ring (missing bearing, wasn't clicking) and then some focusing issues and he quoted me like $40 for each half of the lens, so hopefully it'll be something like $40 to fix this.

It looks like I could fix it myself, but if it can be done professionally for a small amount, I'd rather not risk ruining the blades
 
I'd be interested in what he charges to reset the blades. Another source I know charges $100 for it. It is "no fun".
 
Lens diaphragm repair

Lens diaphragm repair

My guess would be that when you lubricated the focusing and aperture some oil got onto the diaphrgm blades. This would cause severe drag and would be the reason the blade pivot pins have pulled out of the actuating ring.
I would strip down the lens and remove the diaphragm assembly for a thorough cleaning.
Repman2
 
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