Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,233   Posts: 1,532,914   Online: 988
      
Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 32
  1. #21
    benjiboy's Avatar
    Join Date
    Apr 2005
    Location
    U.K.
    Shooter
    Multi Format
    Posts
    6,746
    Quote Originally Posted by 2bits View Post
    benjiboy,
    Thanks for the great tip! I'm getting one right away.
    2bits
    I'm going to ask Ikea to pay me a kickback, maybe they could advertise the lamps as being particularly suitable for this purpose
    Ben

  2. #22

    Join Date
    Oct 2008
    Location
    Townsville, Australia
    Shooter
    Medium Format
    Posts
    41
    I was keen to try this out so I went and bought a cheap no-name brand LED desk lamp from Woolworths, similar in style to the Ikea lamp that people have been posting about above, and tried it out on a significantly yellowed Takumar S-M-C 35mm f2 lens. I put the lens front element down on to a compact mirror and shone the LED lamp through the rear element from above. The results? I checked it ten hours later after just leaving it overnight and the improvement was amazing. Right now it's at the two and a half day mark and I don't think there's been much improvement since my initital check, but it's still early days. Maybe that last bit of yellow is hard to kill. I'll continue to leave it under the lamp and see what happens over the coming days.

  3. #23

    Join Date
    Mar 2011
    Shooter
    35mm
    Posts
    280
    I can confirm that the Ikea lamp works. Mine took about four days exposure to clear completely, I used an old CDR as a mirror underneath the lens to reflect the light back into the lens (and just in case the lens turned out to focus it well enough to scorch the desk!)
    Matt

  4. #24

    Join Date
    Nov 2012
    Shooter
    35mm
    Posts
    332
    Does the yellowing warm or cool images? I always assumed since it was yellow, it would pass more blue

  5. #25
    benjiboy's Avatar
    Join Date
    Apr 2005
    Location
    U.K.
    Shooter
    Multi Format
    Posts
    6,746
    It warms the image on colour film, on monochrome film it has the same effect as a pale yellow filter.
    Ben

  6. #26

    Join Date
    May 2008
    Location
    Germany
    Shooter
    35mm
    Posts
    278
    After my experience the 1:2/35 SMC Takumar is more difficult to clear than the 1:1,4/50. There remains a certain light warm tone. If the 35 mm gets too hot there is a strong risk for delamination of the rear lens element. The 50 mm seems to be more heat resistant.

  7. #27
    benjiboy's Avatar
    Join Date
    Apr 2005
    Location
    U.K.
    Shooter
    Multi Format
    Posts
    6,746
    [QUOTE=jochen;1443918]After my experience the 1:2/35 SMC Takumar is more difficult to clear than the 1:1,4/50. There remains a certain light warm tone. If the 35 mm gets too hot there is a strong risk for delamination of the rear lens element. The 50 mm seems to be more heat resistant.[/QUOTE

    The Ikea Jansjo worklight http://www.ikea.com/us/en/catalog/products/20169658/ produces very little heat and works in removing the yellow caste on Thorium lenses like magic, and after you have removed it makes a very useful reading lamp all for less than $10.
    Ben

  8. #28

    Join Date
    Oct 2008
    Location
    Townsville, Australia
    Shooter
    Medium Format
    Posts
    41
    My experiment has ended so I'll report the results. In the end I left it under the LED lamp for a few hours short of eight straight days. The lens is for all intents and purposes clear. I compared it side-by-side with an SMC Takumar 55mm f1.8 lens, which should have no yellowing, by looking through them both outside in broad daylight on a nice sunny day, and they were identically clear. All up I'd say it's a great success.
    Last edited by fenderslash; 01-10-2013 at 01:48 AM. Click to view previous post history.

  9. #29
    benjiboy's Avatar
    Join Date
    Apr 2005
    Location
    U.K.
    Shooter
    Multi Format
    Posts
    6,746
    Quote Originally Posted by fenderslash View Post
    My experiment has ended so I'll report the results. In the end I left it under the LED lamp for a few hours short of eight straight days. The lens is for all intents and purposes clear. I compared it side-by-side with an SMC Takumar 55mm f1.8 lens, which should have no yellowing, by looking through them both outside in broad daylight on a nice sunny day, and they were identically clear. All up I'd say it's a great success.
    Your uncle Ben told you it works .
    Ben

  10. #30

    Join Date
    Oct 2008
    Location
    Townsville, Australia
    Shooter
    Medium Format
    Posts
    41
    Thanks uncle Ben

    I suppose the main thing I can contribute to the thread is that I've proven that it doesn't have to be that particular Ikea lamp. All similar LED lamps probably work fine.

Page 3 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin