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02-10-2013, 03:33 PM   #1
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Probably last time using beautiful 67 100mm.

Hi all. First post here other than in the welcome forum. Last year I brought along my arsenal of lenses on a trip to the southwest. I had intended to do testing and comparisons in my spare time. Well, with few exceptions, that didn't really happen. I did manage to get a few shots with the 67-100mm macro on my 645D. I had wanted to compare this lens with the A 645 120 Macro that I have and which is a remarkable lens. I'm happy with the few shots I did get, but this past summer I noticed that my 67-100 had a bad nasty in the internal lens elements. It wasn't just the normal slight dust that can get in. Right in the center is a significant curly piece of lint. I made things worse trying to dislodge the offender. My antics caused another internal chunk to end up near the center. It is probably too cost prohibitive to have it professionally cleaned. Since my A 645 120mm is so nice and I also have the 67-90 (which I haven't shot with yet), I will probably never again use my 67 100. It's too bad because it is otherwise a fine lens. Anyone interested, I have a few of my 645D photos at 500px. 500px / Richard Longseth / Photos


Last edited by Richard Longseth; 08-22-2014 at 08:28 PM.
02-10-2013, 04:19 PM   #2
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I really like #2 - well seen - great light too.

Sorry to hear about the lens.
02-10-2013, 04:30 PM   #3
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Sorry about the lens. You might try sending it to Eric for an evaluation. He doesn't charge to estimate what it would cost to clean and he'll return the lens to you at his expense if you decline the estimate.
02-10-2013, 06:08 PM   #4
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Thanks for the comments. Sending the lens to Eric Hendrickson is a good suggestion and I think I might do just that. Eric repaired both my Pentax 67 and 67II a couple years ago, and did a great job. I had forgotten about his service somehow. The thing is, soon after is when I purchased the 645D, and I haven't used my film cameras since. Not that they are for sale - it's hard to part with something I've spent so much time with.

02-10-2013, 06:43 PM   #5
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You have some impressive images in your portfolio, very nice!

All lenses breathe when the focus ring is turned and airborne dust gets in, there isn't much you can do to prevent that. My attitude towards dust in the lens; if it can get in, it can come out. Those 2 pieces of lint in your 67-100 lens probably won't affect the IQ at all but admittedly, it's not pleasant to look at. I've had good success at dislodging the dust on the glass elements by blowing in the lens with canned air. Most older lenses when focused to MFD, the rear element group moves away from the body. Shine a flashlight in the rear of the lens and look for cavities that might go to the front elements, insert the nozzle of the canned air in the lens and give a couple of short blasts (open the lens diaphragm wide), repeat the process from another spot on the lens. You should see a definite reduction in the amount of dust on the glass. Where does the dust go, I have no idea. Maybe I am breathing it or it might get trapped by the grease on the helicoid gear.

Some people are concerned about the propellant coming out in it's liquid form. As long as the can has not been shaken and used in the upright (near as you can) position, the can won't gush out any liquid. Even if it does come out, it will evapourate within seconds. I've tested the canned air by violently shaking the spray bomb for about a minute and sprayed it immediately through the narrow red nozzle about 3 inches from the glass surface. First two blasts emitted liquid propellant (no more after) and the propellant left no residue (nothing I could see or feel) after evapouration.
02-10-2013, 07:56 PM   #6
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I did use canned air, although I didn't open the lens diaphragm, or use a flashlight. I was working over my light table. I also tried whooshing by quickly rotating the focus, without banging into the stops, in an attempt to create some air movement. The lint did move some, not out, and thats when a chunk of something got lodged on the element. Double the trouble. Now, thinking it was not the thing to do, but doing it anyway, I got out the shop vac hoping to suck the little buggers out. That did nothing but put little abrasions on the black paint. Hopefully the vacuum didn't dislodge the lens elements. After a fair amount of trying I finally gave up on it. As far as not affecting the IQ, I think that it depends on how large, and the position on the lens element. In the days of old, for years, I shot with a Toya 4x5 view camera. My favorite lens was a 90mm Super Angulon. That was a great lens. Same thing happened, and there was a definite blur spot that was apparent in photos with an even or uniform tone, like a clear blue sky. Thats before I knew anything about photoshop, and a lot of otherwise good transparencies found the waste basket. The 645D is such a nice camera, and with all the time and effort to go out and get the photos, I want to make sure my lenses are as reasonably good as can be.
02-10-2013, 09:49 PM   #7
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View camera lenses are totally different from small format lenses. You have two sealed units that screw into the shutter, one in the front, one in the back. The focusing is done by moving the bellows, the lens elements remain stationary. You probably had lens separation, which is totally different from dust sitting on the element. Lens separation changes the lens alignment which becomes more and more apparent and visually affect the image as the lens is stopped down further. If dust was the culprit on your Super Angulon 90, simply unscrewing the two sealed units from the shutter and cleaning the two inner glass surface would have solved your problem.

The 645D is a very nice camera but in the end, it's just a camera. As for the lens, it is your lens and you can do whatever you like with it but to declare to the Forum-at-large, your intention to consign a lens to a deep corner of your lens shelf indefinitely because there are a couple of pieces of lint inside the lens, without actually field testing the lens to see whether the lints would affect the IQ or not, seem... sorry, can't think of fitting adjective/s to describe my take on it.
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