I just got a good deal on a Rodagon 80mm f/4 on eBay (I know, I know, but I'm trying to set up a darkroom on the cheap!). Everything seems to be in good shape, except one thing I noticed when taking a good look inside the lens. If I close down the aperture, I can see two tiny cloth fibers a few dust motes lying on an internal surface. It looks like if I were to close down to f/11 or more, the fibers would not be in the light path.

I'm wondering...are these things going to interfere with image quality? If so, is it possible (or advisable) for me to try cleaning it myself?

Quick! While I still have a window of time to return it! :rolleyes:

-g.

Gary:

Based on your description, I doubt that the dust you see will have an appreciable effect. At most, it might have a very tiny effect on the contrast. I would not try to clean it.

If the lens is otherwise in good shape, I wouldn't worry.

Good luck with the darkroom.

Matt

Good to know I won't get big enlarged cloth fiber images on my prints. Thanks for the info and the luck!

-g.

The effect on the image of minor contamination between the lens elements would usually be a loss of contrast.

One thought - the Rodenstock f/4, 80mm does have a front element that is, more or less, easily disassembled. I discovered that when using a "softening" filter - 40.5 mm screw-in. The front assembly - down to the iris diaphram - can be removed. There is a shim there - probably of "custom" thickness to provide proper element spacing. If you do disassemble this lens, be *very* careful to replace this shim in its original configuration.

I have to think that this lens was disassembled - as above - before and for some reason, reassembled with foreign material inside. Hopefully it was reassembled properly ... but IMHO there is some (probably not great) chance it was not.

My only advice would be to try it "as is". If you are satisfied with the results, leave it alone, and use it. If not, I would contact Rodenstock - Googling will get their address. MOST of their enlarging lenses carry a lifetime guarantee, and in any event, I've found them to be most reasonable ... GOOD people, in the past.