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01-29-2010, 06:23 PM   #1
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SMC M 80-200mm f4.5 sticky aperture

So, I recently ordered an M 80-200 off ebay for quite cheap (less than $10 minus shipping), and it arrived today. The description stated that it was in "great" condition and had "no issues." Due to a lack of real descriptive terms, I realized that oil on the aperture would be something that I might have to deal with, as the seller did not appear to know too much about lenses. As it is, there is some oil on the aperture blades, but the odd thing is that it is only sluggish some of the time. If I flick the lever a few times, it is slow at first but then appears normal and snappy. With sample shots, I haven't noticed any overexposure and the metering appears to be working just fine. Besides the oil and some zoom creep (is that expected on the M 80-200?), it works great and is cosmetically pretty decent. Images are quite sharp

So now I'm wondering, is it worth it to do anything? I kind of don't want to go through the hassle of sending this thing back, as the shipping ended up costing more than the lens itself. I know that the problem will only get worse, but I wouldn't mind experimenting and trying to clean it myself at some point in the future. Does anyone here have any experience cleaning this particular lens?

Picture of the oil for those who care

01-29-2010, 06:30 PM   #2
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Original Poster
Okay, so apparently my attachment didn't work... so here it is again.

07-24-2011, 04:49 AM   #3
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I have just encountered the exact same scenario. I was actually after a 75-150mm, which I regreted selling in the past, and then saw this alongside a Kiron 28/2 which hadnt been noted in the sale, and I thought what the hell, its effectively a freebie. And its got oil on the blades. And it looks like it only slows up some of the time, and even then doesn't really do it much. I am wondering whether its worth fixing...I am guessing the internals of this are complicated due to the constant f4 aperture....what did you do in the end please?
07-24-2011, 08:32 AM   #4
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Aperture blades are right in the middle of everything, so there's always a chance of considerable disassembly. That means tools. A lens spanner and a set of JIS screwdrivers would be extremely handy. Improvised tools might work, or get you halfway, then stuck. The less experience you have, the happier you'll be spending money on tools.

With an unknown lens, you have to gamble on a starting point. On a zoom, try the end that doesn't move that much, the mount side. From the optical diagram, it looks like 12 elements, half on one side of the aperture and half on the other, so either side has a lot of stuff. Set up a system to document each step, because you can often get to the problem, fix it, then forget how to reassemble.

Another option is to sell it. Somewhere out there, someone needs a part, or a project, or an assembled lens so they have a guide to fix their pile of parts. Document the problem and put it up for a minimum price.

07-24-2011, 12:41 PM   #5
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yep, given the time involved, and the likelihood of success given I failed to fix a Cosinon 24mm recently, I think I will be better off letting someone else have this to play with instead
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