I have been looking for an enlarger lens for my 8x10 enlarger, and have come across one that has oil on the aperture blades. It functions fine, but I wonder about the oil. I Know that on a camera, that would be a problem - but on an enlarger lens?
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I have been looking for an enlarger lens for my 8x10 enlarger, and have come across one that has oil on the aperture blades. It functions fine, but I wonder about the oil. I Know that on a camera, that would be a problem - but on an enlarger lens?
Quote:
Originally Posted by cyrus
Why do you think there would be a difference between camera and enlarger? I always heard that it was a problem, but never knew why it would be (within limits of course). I have lenses with and without oil and don't see a difference in performance. Do you know what the problem is suppose to be?
I think the problem is usually a matter of oil on the 'shutter blades', where reflections could be thrown around as the shutter opens and closes.
As for oil on enlarger aperture blades it can easily be 'washed' off after removing the front and rear cell. The barrel is much simpler than a shutter,...but watch out for aperture blades coming off....could be better to hand it to a professional for cleaning.
Hi there,
"Do you know what the problem is suppose to be?"
The problem is friction and leverage. The pivot pins at the ends of the blades are tiny and only swagged into place. The surface tension / friction caused by the oil between the blades will eventually over-strain the pins and break one, then the aperture jams. It's better to have it cleaned and lubed properly, enlarger lens are usually very easy to service.
The oil might also vaporize and redeposit on the glass causing spotting and a good place for dirt to collect. I have cleaned oil off shutter blades with a q-tip and pure alcohol--rubbing alcohol usually has a large amount of water in it...
Michael
Michael
oil on shutter blades will slow the shutter. especially when the oil starts to get thick. oil on ap blades may cause them to stick. i have, in the past, and just yesterday on a copal shutter, removed the lens elements, and gave the shutter blades a shot of lighter fluid. the shutter was starting to stick in a partial-open position, and the ap was not wanting to open fully. after the shot of lighter fluid, i worked the shutter several times to clear the oil. works great now. the lighter fluid contains naptha. cleans well, has no oil base and evaporates quickly. try at your own risk. or give it up with a few bucks and have it professionally cleaned/lubed/adjusted. money well spent on a good shutter or barrel aperture.
Be careful with the lighter fluid! I partially dissolved the old blades of a shutter with it--they turned out to be some kind of plastic (Bakelite?).
Michael