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artyvisual
4-Nov-2013, 07:08
I bought a Apo Ronar 480mm (really cheap), but when it came in, I saw that the front lens element was in bad shape. I openend it up. I never seen these kind of marks before. It is a process lens. What vould have caused this. I guess this makes the lens useless 104067

Mark Sawyer
4-Nov-2013, 12:18
I see lots of scratches, and the big blobs could be separation, though it's hard to say from the photos. Try it and see, I have some terrible looking lenses that work quite well...

EdSawyer
4-Nov-2013, 12:49
Yeah just try it - you would be surprised how bad a lens needs to be before noticing the difference on film.

E. von Hoegh
4-Nov-2013, 12:50
That's pretty bad, more than just a contrast issue there. It will still make pictures, but nothing like what it should do. I doubt it's separation, the 480 doesn'y have cemented elents AFIK. Can you return it?

Steven Tribe
4-Nov-2013, 12:51
I believe this is a dialyt - so this is a single lens? If this isn't a coating problem, then the glass surface has been attacked by something.

artyvisual
4-Nov-2013, 12:54
It isn't seperation, because it is a picture of a single lens element. (I opened the (air spaced lens) It could be (partial) fungus as someone told me... I will try the famous amonia-peroxide mixture; see what that will do....

lenser
4-Nov-2013, 16:37
Ever seen a Petri dish with circular colonies of whatever agent is being grown? That's kind of what this looks like, so I'm betting this lens once had some serious fungal colonies that have etched into the glass. As others have said, it may still shoot quite well, but I would expect to see flaring if shot toward a light source.

Geoffrey_5995
4-Nov-2013, 20:44
Looks like bubble wrap was pressed against the surface for a period of time and left marks in the coating. Just a thought.

Jim Graves
4-Nov-2013, 22:07
That looks like a large number of micro scratches ... and the circular features are way too regular to be fungus.

I'd leave it to soak for a couple of days in a solvent ... Like xylene or acetone ... it won't help the scratches but I'm guessing the circle features will disappear.

And, I agree with Mark and Ed ... take a few shots with the lens before you ditch it ... you might lose a lttle contrast and you might not want to shoot into the sun but you will be surprised how little impact the scratches have on the image result. A large percentage of my lenses are "defective" .... and, therefore cheap ... and they all take very nice pictures. Buying "damaged" lenses is a great way to afford some otherwise unaffordable glass. I have a 360 APO Ronar as my primary lens for 8x10 ... wonderful lens.

artyvisual
5-Nov-2013, 01:18
Well, the problem of trying the lens out is that I first need to buy a lensboard for it to mount it on, (flange), and an extension rail for my Sinar as I don't have enough bellow extension for 480mm, so that will set me back around 100 USD... I am a bit reluctant to do that for this lens. I will try to soak the lens, and if any improvement, will post the 'after' picture.

Jim Jones
5-Nov-2013, 06:50
Instead of investing in an extension rail, lens board, and flange, one can improvise a top hat lens board from mat board, a tin can, and duct tape for testing at least the center of the image. The lens will probably need additional support.