When all the hybrid and plastic lenses begin to turn yellow

Discussion in 'Digital Photography' started by RichA, Sep 21, 2010.

  1. RichA

    RichA Guest

    Complex lenses today using aspherics are all plastic, plastic-glass
    laminates, except for the most expensive custom lenses. Plastic
    lenses are not changeless.
    Think of the inevitable yellowing as a built-in haze filter! Remember
    old Pentax Takumars (30mm f2.0 for e.g.) that turned yellow from
    radiation? Well, the plastic in the new lenses will be doing the
    same, likely sooner, from UV exposure.
     
    RichA, Sep 21, 2010
    #1
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  2. RichA

    Griffin Guest

    No he does not. Iff he is aa troll rememberTrolls are not required to back
    up statements with anything.

    Griffin
    ..
    --------------------------
    The Internet will become the
    Sacred Sanctuary for Nutters,Idiots
    And Trolls

    (Michel Nostradamus, December 14, 1503 - July 2, 1566).
    --------------------------
     
    Griffin, Sep 21, 2010
    #2
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  3. RichA

    charles Guest


    Doesn't matter. If we followed Rita's advice, we'd throw everything
    away when it got to be 18 months old, buy new stuff.

    Everyone does that, right?
     
    charles, Sep 21, 2010
    #3
  4. RichA

    Bruce Guest


    Now I realise why almost everyone whose glasses are more than a few
    weeks old have bright yellow lenses.

    Thank you for providing a logical explanation. ;-)
     
    Bruce, Sep 21, 2010
    #4
  5. RichA

    RichA Guest

    It's not speculation. I've seen a lens from the 1980s with a plastic
    element that had turned yellow. A cheap zoom. Of course, in the
    1980's, only cheap lenses got plastic elements.
     
    RichA, Sep 22, 2010
    #5
  6. RichA

    Bruce Guest


    Make sure you store them with the lens caps off so that the stored
    light can escape. Otherwise, the light will carry on bouncing around
    in there, making the plastic elements go yellow.
     
    Bruce, Sep 22, 2010
    #6
  7. RichA

    DanP Guest

    30 years is a pretty good lifespan for a cheap lens.
    Still usable on AW balance.

    DanP
     
    DanP, Sep 22, 2010
    #7
  8. RichA

    DanP Guest

    Thanks for your feedback ;)

    DanP
     
    DanP, Sep 22, 2010
    #8
  9. RichA

    Twibil Guest

    Yup. Just as enough sunlight causes glass -and the coatings
    thereon- to turn various colors.
    Tsk! You're going to give poor RichA a stroke if you keep on being
    reasonable!

    Let's please have a little more foaming outrage over nothing very
    much.

    ~Pete
     
    Twibil, Sep 22, 2010
    #9
  10. Well, yes.

    And that's why it is well studied. For example, in fluorescent light
    fixtures. That's with the plastic an inch from a high-UV source. Or
    in lenses for arc lamps. I found a study which showed substantial
    yellowing in an acrylic lens 4 inches from a 400 watt mercury lamp ...
    in 3 years. Or polycarbonate in one year. That perhaps a million
    times brighter than a camera lens sees.

    I've used acrylic plates as structural material, some of them
    an inch thick and going on 40 years old ... and they show horrible
    scratching and crazing, but no yellowing, sitting in a well-lit lab.

    Doug McDonald
     
    Doug McDonald, Sep 23, 2010
    #10
  11. RichA

    shiva das Guest

    My eyeglasses cost $1,200.00/pair and I generally need new ones every 9
    - 12 months. I have old glasses on display, mine reaching back to the
    1970s, all with plastic lenses, none yellow.

    My wife's Varilux glasses are aspheric but not molded. Current optometry
    art is to CNC machine the lens blanks to match her specific vision
    requirements.

    We both donate our old eye glasses to the Lion's Club and at least get a
    tax write-off for part of the purchase price.

    I also have a large collections of cameras and lenses stretching back
    the the early 1900s and of the entire stock none of the lenses have
    yellowed (yes, I know, the oldest ones were glass), and some very
    obscure Leica lenses with Lanthanum glass, and some Nikon lenses with
    fluorite elements. A Nikon EM from 1978, complete with an "E" plastic
    lens. In perfect shape.

    Watch crystals, however are another story. They are made of simple
    uncoated acrylic, and I have been lucky enough to snap up some deals on
    some nice watches on ebay because the crystal was bright yellow. If the
    seller thinks the dial has yellowed (a very expensive repair in the
    vintage world), well, what can I say. I repair watches as a hobby...
     
    shiva das, Sep 23, 2010
    #11
  12. RichA

    Peter Guest

    Would you mind contacting me off line.
    peternew at optonline.net.

    I have a question about repair of an old music box, circa 1890.

    thanks,
     
    Peter, Sep 23, 2010
    #12
  13. RichA

    Peter Guest


    Let's just say I saw a similar box, without the disks, selling at retail for
    over $7,500. I have about 4 disks and would like to repair the mechanism.

    I am really looking to sell now, but it can't hurt to fix the box.
     
    Peter, Sep 24, 2010
    #13
  14. RichA

    peter Guest

    Oops!
    I should have said I am "not" looking to sell. This is a small desk top
    music box, made in Austria.
     
    peter, Sep 24, 2010
    #14
  15. RichA

    tony cooper Guest

    I think I submitted this to a Shoot-In some time ago:
    http://tonycooper.smugmug.com/Photography/Miscellanea/musicbox/656970514_Sjxm9-XL.jpg
    I think this disk was about 15" to 18" in diameter.
     
    tony cooper, Sep 25, 2010
    #15
  16. RichA

    John Turco Guest


    The most convincing refutation of our Canuck curmudgeon's ("RichA") rather
    ludicrous assertion, is the continued good health of countless secondhand,
    low-end cameras - both with, and without, plastic lenses - the world over.

    I, myself, own quite a few of those items. Furthermore, I typically see
    numerous examples of such merchandise, when visiting thrift shops.

    So, when all is said and done...Richard Anderson >still< can't troll his
    way, out of a paper sack!
     
    John Turco, Sep 25, 2010
    #16
  17. I am obsolete, too:) I have a turntable and a cassete deck, I also have a
    cassette radio in my car. I clearly remember our 8 track receiver, which we
    unfortunately gave away. I also like listening to '80s music, and watching
    old films:) My favourites by far are the original star wars and alien.
     
    Tzortzakakis Dimitris, Sep 25, 2010
    #17
  18. RichA

    Peter Guest


    Then post them and end the bull.
     
    Peter, Sep 25, 2010
    #18
  19. RichA

    Twibil Guest

    Well, not really.

    Because when he (?) says "you and DaffyDuck, numbnuts, and others of
    your ilk", it translates accurately as "everybody".
     
    Twibil, Sep 26, 2010
    #19
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