"Bleaching" yellowed rare-earth element glass

Discussion in 'Adapted Lenses' started by qball, Sep 3, 2010.

  1. qball

    qball Mu-43 Regular

    170
    Jun 19, 2010
    I understand you can remove the yellowing of certain rare-earth element glass lenses that have yellowed with age. Like the Konica 57mm/1.2.

    Besides the "brightly lit" room method, I understand you can bleach it with prolonged exposure to UV light.

    What kind of UV light specifically? Like a UV blacklight? Or the type of UV light you would use to sterilize things?

    [​IMG]

    or

    violight-uvwand.
     
  2. antithetic

    antithetic Mu-43 Regular

    150
    Jun 7, 2010
    City of Angels
    Couldn't you leave it in direct sunlight for a few days/weeks?
     
  3. qball

    qball Mu-43 Regular

    170
    Jun 19, 2010
    Yeah, but I'd rather leave it in a closet with a light, as we have six mischievous dogs and my lens would end up as a toy.
     
  4. antithetic

    antithetic Mu-43 Regular

    150
    Jun 7, 2010
    City of Angels
    Oh. Didn't know mischievous dogs were in the mix. =]

    I found a thread on Flickr which discusses using UV light to get rid of yellowing on the lens. Basically one poster found the yellowing decreased by using a regular UV blacklight. It's slower but safer (for humans).

    Hope this helps.