Mamiya 80mm 1.9 N with haze, fixable?

Discussion in 'Medium Format' started by alpshiker, Oct 14, 2014.

  1. Hi,
    I just purchased a mint looking N lens from Japan on the bay. To much of my surprise though, the rear element has haze, in such extent that it is unusable. I am assuming that this is due to balsam opacity, or perhaps separation in the rear element. Having it fixed would probably cost more than the $300 I spent so far, if such was available. I will certainly obtain from the seller that he takes it back, for he mentioned no problem with glass. The lens looks so good however—it is like new—, that it's heart breaking to dump it. Has anyone had success in removing haze from a 1.9 N? Are rear lens cells still available?
  2. Unscrew the rear element from the shutter/barrel and clean the internal surfaces then reassemble.
    Your picture looks like lubrication/paint/plastics used in the lens housing gassing out and collecting on the internal surface(s).
  3. Thanks for this advice Charles. If it were not for some worrisome posts I have now found elsewhere, I would probably try. Others have done that to find out that the haze stood between the glued elements. It looks as though this is a programmed genetic illness of the 1.9N, or at least of some batches of it. The older C has another design. I should probably send it back. I am now a little worried for the handful top mamiya lenses I have in my bag. Is balsam fogging known to occurr on other N lenses?
  4. I'm working off general lens knowledge, your research on this brand is most likely more accurate but...
    Several years ago I purchased a Goertz Dagor that was cloudy. While it was difficult to focus exposures were OK.
    I decided to recement it. After heating it in a 250°F oven for 30 minutes at a time and putting the cloudy element in boiling water 3 or 4 times each I put it back together and put it away as the elements would not separate. I took it out a few months later and it was crystal clear. Go figure.
    Direct heat can cause damage. Indirect heating such as putting the lens in a heated oven and turned off, lowering into a 2 quart pan of boiling water removed from the heat source or similar heating technique may separate the cells for recementing or repair the balsam.
    If you have the option of returning it and do not wish to experiment return it. If you recement it the alignment of the cells is critical. Put a single line on one side and a double line on the opposite side that won't rub off.
  5. Interesting outcome with the Dagor! I suspect that the balsam has crystallized and heating the lens element reversed the process? Modern lenses use different chemical compounds, some are two components, others harden with UV light. It's not certain that they would melt with heat. But certainly worth experimenting if the lens is dead anyway.
  6. Return it for a full refund, if you try fixing it yourself the seller can claim that you damaged it. Also the seller should have been honest with you up front. I've had this problem before with amateur sellers who don't realize that the only proper way to check a lens is by shining a flashlight through it. And eBay usually guarantees the refund if the seller gives you any problem.
  7. The seller was I think, unaware of the problem. He politely apologized and offered a full refund. All is well.
  8. Arrange for return/refund ASAP. They don't grow on trees, but 80/1.9s aren't all that rare. Wait for a better one.
  9. Yes, if you paid a 'regular' price for it, return it.
    There are lots of reasons for 'fogged' internal elements, and not all of them are easily corrected. It might be grease or glue that has 'out-gassed' but it is not impossible for acids to have affected the glass itself.
  10. Not sure, but I had this lens that I used in the rain often, not drenching rain, but rain nonetheless. I tried to sell that lens after it sat for awhile for months. The buyer refused to pay me what I asked for because he said the lens was fogged. He offered a lower price. I was totally not aware of the fog.
  11. Norland Optical Adhesives, , UV to cure, warm soapy water or acetone to debond components.
    Maybe getting the lens damp is the source of the fog.
  12. Not something I would tackle, but Steve Mallett provides some practical does and don't from his experience on this page (unsigned).
    My single experience at taking a lens apart is almost 40 years old. It was a nice Nikkor 50mm 1.2 that an australian friend used for underwater photography (some might remember the price tag, a month of my wage). It had fungus, so I offered to clean it. All went well, elements clean, when the last lens to get in slipped from my hands and crashed onto the concrete floor… Reminds me that I must bring him a new one when I get to heaven.
  13. Hi @alpshiker, I got the lens with same problem. Have you ended up cleaning haze successfully? I'm trying to disassemble it to get to the problematic cement but I can't remove the 2 lenses that have haze metween them from the metal ring that holds them. Could you maybe advice me how to remove the glass elements, so I can later separate them and re-cement? Or point me to someone who done it successfully? Thanks a ton!

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