You can use any IKEA LED for yellow glass treatment

nandakoryaaa · Joined: 07 Sep 2014 Posts: 95

There is a technique, which you must already know, for curing the yellowed rare-earth glass with some particular IKEA LED lamp.

I went to IKEA and examined all lamps there. They all use the same LED, so you can buy just the bulb or other lamp, because the suggested one is rather expensive.

I bought one bulb with flat top and it is exactly the diameter of a Super Takumar 50/1.4 which I put face down on the bulb and secured with scotch tape. The yellow was almost gone within 24 hours. There is still some very light yellow tint, and maybe it cannot be removed as easily. But I decided to leave it as-is because actually I prefer this lens giving the warmer look.

It had no problems with color even when it was untreated, so there is absolutely no problem with the remaining tint.

Jesito · Expire: 2015-01-07

Interesting, that means the LED bulb is emitting some strong UV radiation.... Not nice to me. Sad

Could you please tell us which IKEA bulb was that?. They name their bulbs LEDARE generically.
So far I've been using UV fluo lamps for this (I got some from the use of EPROM erasers) and also some specific UV LEDs (single 1W LEDs). UV radiation is harmful to the eyes and the skin, so now I'm a bit concerned with the fact I've replaced all my bulbs at home by LED ones, most IKEA LEDARE ones.

nandakoryaaa · Joined: 07 Sep 2014 Posts: 95

kds315* · Expire: 2021-03-09

Hmm, surprising, as I honestly doubt that UV is contained in that LED radiation.

nandakoryaaa · Joined: 07 Sep 2014 Posts: 95

DigiChromeEd · Joined: 29 Dec 2009 Posts: 3462 Location: Northern Ireland

I recently posted a thread on this topic:

http://forum.mflenses.com/fast-lens-de-yellowing-without-a-uv-lamp-t68896.html

nandakoryaaa · Joined: 07 Sep 2014 Posts: 95

Crabby · Joined: 13 Feb 2014 Posts: 9 Location: Texas

"Irradiated" a Super Tak 1.4 with noticeable yellow cast for two days. Could discern perhaps some lesser tinting, but outdoors color balance still off, so did another day's worth of led treatment, without noticeable change. Would have been nice to have my chem lab spectrophotometer to actually measure the transmitted light. But, retired now, and anyway was spared further ado as last night put MC Rokkor 28 2.5 under the lamp, which promptly went poof as led bulb burned out. Approx four days use and I had tossed the Ikea receipt. Curious whether anyone has actually measured the transmitted spectrum before and after treatment. A detailed histogram from before and after of a shot of white background?

visualopsins · Expire: 2025-04-11

I guess the yellowing does respond to wavelengths longer than UV. Wink

Some of it, at least, given experiences here, and my own.

The question remains, will more treatment of led-treated lens using UV remove the remaining yellow cast?

I had 5 yellowed 50mm Takumars -- using sunlight, 2 cleared complete. The sunlight exposure helped the remaining 3, but they still had various degrees of yellow leftover. I tried to remove leftover yellows using several months of daily sunlight exposure -- nothing happened. I did notice the initial yellow easily cleared had more "haze" than the leftover yellow, which is very transparent.

Himself · Expire: 2013-05-30

Crabby · Joined: 13 Feb 2014 Posts: 9 Location: Texas

False alarm on the demise of the LED...either the cat or evil spirits unplugged the lamp overnight. So, the Tak is getting more tanning booth treatments compliments of Ikea. Probably put it out in sunlight next. Most likely simply reserve it for monochrome use on the Sony or Olympus. If anything interesting happens, I will post. Ciao.