Ikea Lamp and Takumar Lens

Fiddler · 03-26-2015, 04:26 PM - **3 Likes**

After reading of experiences of people who have had success removing the Yellowish Colour cast from various vintage lenses , decided to give it a go.

Apart from Light show, which looks , I think, pretty neat, the Lamp truly does appear to work as reported.

I initially checked it at 24 Hours and then gave it another 24hours. Sure 24 was enough, as I couldn't see any further improvement.

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carpents · 03-26-2015, 07:20 PM

Which lamp exactly?

stevebrot · 03-26-2015, 08:00 PM

Thanks for confirming that this works.

OTOH, this is sort of scary if you consider that the lamp must be pretty strong at the UV end

Steve

rawr · 03-26-2015, 08:22 PM

The lamp will probably work nicely to kill fungus too, if need be.

Fiddler · 03-26-2015, 11:04 PM

Originally posted by carpents

Which lamp exactly?

JANSJÖ LED work lamp - black - IKEA

$9.99

---------- Post added 03-26-15 at 11:20 PM ----------

Originally posted by stevebrot

Thanks for confirming that this works.

OTOH, this is sort of scary if you consider that the lamp must be pretty strong at the UV end

Steve

Don't know how much UV it pumps out. I went to look for one, as this seems to be known to do the job.

A single LED. A/C adapter says output is 4 Volt.

I placed the Lens (wide open) and directed the light into the rear lens element. Lens sat on a Mirror to reflect light back through.

Take the Lens away and it looks just like any low powered reading light.

I've read some people have used Aluminum Foil if no Mirror is available. Initially I did that for 5 or so Minutes, but wasn't impressed with the reflectivity, so out came the Mirror.
Adjusted the light way down toward the lens, it's also the perfect size, and left it about 1/8" inch above the Glass for 24hours. It was clear then. The other 24 hours was just "to see".
Stays cool, no heating of Lens Glass or Body.

I would feel uncomfortable leaving most things out in the Arizona Sun, so a Lamp was my only way to go.

---------- Post added 03-26-15 at 11:23 PM ----------

Originally posted by rawr

The lamp will probably work nicely to kill fungus too, if need be.

Wonder would it cook Mushrooms ? lol !

https://www.pentaxforums.com/forums/images/smilies/lol.png

**k0og** · 03-27-2015, 06:52 AM

I'm glad to see this thread - and confirmation from others that it works. I bought one of these lamps about a year and a half ago and used it on two yellowed Super-Takumars (50mm f1.4 and 35mm f2) and it worked for me.

By the way, I use the lamp at my work bench and it is convenient for working on small things because of the directed light. It's a good price for a lamp like this!

-Joe-

narual · 03-27-2015, 08:56 AM

Oh wow. I have several of these, plus the clamp version. I bought them in my apartment when I was working away from home for a few months and then brought them home with me when I started working remotely.

My wife and I use two of the clamp ones as reading lights since our bed is in the middle of a round room and we couldn't do wall mounted lights, and the headboard is made of metal tubes, so couldn't screw lights into that, either.

Aside from the two we use as bedroom reading lights, the rest I mostly use when I'm playing with macro. I have an apparently discontinued ikea white glass desk, and they're great companions to that -- I can clamp the clamp ones onto the edge and light it up from beneath and use the desktop ones all around the object. They even do a decent job making jewelry sparkle. They're so tiny that they don't get in the way, the gooseneck is nice and does a good job keeping them in place... and now you can use them to clean old lenses, too?

stevebrot · 03-27-2015, 09:43 PM

Originally posted by Fiddler

and left it about 1/8" inch above the Glass for 24hours.

Only 24 hours? That is very cool! I only have a couple of yellowed lenses (both non-Asahi), but the thought of baking them in full sun does not appeal to me.

Steve

Fiddler · 03-28-2015, 07:16 AM

Originally posted by stevebrot

Only 24 hours? That is very cool! I only have a couple of yellowed lenses (both non-Asahi), but the thought of baking them in full sun does not appeal to me.

Steve

Ditto on the Sun exposure, especially in AZ. I routinely evacuate the Garage at the start of the "warm season" here of Adhesives, Tape, and anything else that may be affected by excessive heat .

Just the thought of leaving a Lens in the Sun makes me shudder. I've read some folks wrap the lens body in Aluminum to keep the body cool , or leave the Lens on a ledge on a Window Frame also.

24 and 48 hours side by side. I imagine a stronger Color cast might take a little longer ?.

Stavri · 03-28-2015, 07:53 AM

Cheap uv sanitizers work well in removing yellowing on radioactive elements. I use them routinely to kill/prevent fungus and for general maintenance

titrisol · 11-11-2020, 01:14 PM - **2 Likes**

I'll be darned, it works!! My 50/1.4 has been in storage for 8yrs and I had nothing to lose.
It was clear in about 8h of exposure (10:00 to 18:00) but left it for a full 24h

This lamp doesn't emit UV, but while trying to understand how, I found this interesting document from the 70s about discoloring of glass exposed to radiation.
When clear glass (borosilicate) is exposed to radiation is turns amber/brown and it was proven that intense light is sufficient to clear the brown by the hit of photons on the unstable colored compounds

Effects of ionizing radiation on selected optical materials: An overview (Technical Report) | OSTI.GOV

**psoo** · 11-16-2020, 05:09 AM

I'm sure that for psychological reasons it's nice to remove the yellow tint from a lens. However, does yellowing significantly change the color of the image? If it does, some photos may benefit from a warmer glow. If not, why bother?

**pepperberry farm** · 11-16-2020, 05:11 AM

Originally posted by psoo

I'm sure that for psychological reasons it's nice to remove the yellow tint from a lens. However, does yellowing significantly change the color of the image? If it does, some photos may benefit from a warmer glow. If not, why bother?

it does change the image - some like the image with and some like it without the yellowing....

**pepperberry farm** · 11-16-2020, 05:12 AM

I use a different lamp to get the yellow out of my thoriated lenses:

amazon.com: UV LED Black Light, HouLight High Power 10W LED Blacklight Flood Light IP65-Waterproof (85V-265V AC) for Blacklight Party Supplies, Neon Glow, Glow in The Dark, Birthdays, Blacklights, Curing: Home Improvement?tag=pentaxforums-20&

stevebrot · 11-16-2020, 10:04 AM

Originally posted by psoo

I'm sure that for psychological reasons it's nice to remove the yellow tint from a lens. However, does yellowing significantly change the color of the image? If it does, some photos may benefit from a warmer glow. If not, why bother?

The short answer is yes. Yellow is not a very good description for the discoloring. It is closer to tobacco stain in tint. There is also the matter that it is due to a disruption of the physical structure of the glass at the molecular level with attendant change in refractive character. (At least that is the theory.) My experience as well as that of others is an improvement in optical performance when cleared. Of course, YMMV.

Steve

11-11-2020, 01:14 PM - 2 Likes	#11
titrisol Pentaxian Join Date: Dec 2007 Location: In the most populated state... state of denial Photos: Gallery \| Albums Posts: 1,853	I'll be darned, it works!! My 50/1.4 has been in storage for 8yrs and I had nothing to lose. It was clear in about 8h of exposure (10:00 to 18:00) but left it for a full 24h This lamp doesn't emit UV, but while trying to understand how, I found this interesting document from the 70s about discoloring of glass exposed to radiation. When clear glass (borosilicate) is exposed to radiation is turns amber/brown and it was proven that intense light is sufficient to clear the brown by the hit of photons on the unstable colored compounds Effects of ionizing radiation on selected optical materials: An overview (Technical Report) \| OSTI.GOV Last edited by titrisol; 02-13-2021 at 12:57 PM.

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03-26-2015, 07:20 PM	#2
carpents Veteran Member Join Date: Sep 2006 Location: West Chester, PA Photos: Gallery \| Albums Posts: 1,420	Which lamp exactly?

03-26-2015, 08:00 PM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Thanks for confirming that this works. OTOH, this is sort of scary if you consider that the lamp must be pretty strong at the UV end Steve

03-26-2015, 08:22 PM	#4
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	The lamp will probably work nicely to kill fungus too, if need be.

03-26-2015, 11:04 PM	#5
Fiddler Forum Member Join Date: Jan 2015 Location: Arizona Posts: 57 Original Poster	Originally posted by carpents Which lamp exactly? JANSJÖ LED work lamp - black - IKEA $9.99 ---------- Post added 03-26-15 at 11:20 PM ---------- Originally posted by stevebrot Thanks for confirming that this works. OTOH, this is sort of scary if you consider that the lamp must be pretty strong at the UV end Steve Don't know how much UV it pumps out. I went to look for one, as this seems to be known to do the job. A single LED. A/C adapter says output is 4 Volt. I placed the Lens (wide open) and directed the light into the rear lens element. Lens sat on a Mirror to reflect light back through. Take the Lens away and it looks just like any low powered reading light. I've read some people have used Aluminum Foil if no Mirror is available. Initially I did that for 5 or so Minutes, but wasn't impressed with the reflectivity, so out came the Mirror. Adjusted the light way down toward the lens, it's also the perfect size, and left it about 1/8" inch above the Glass for 24hours. It was clear then. The other 24 hours was just "to see". Stays cool, no heating of Lens Glass or Body. I would feel uncomfortable leaving most things out in the Arizona Sun, so a Lamp was my only way to go. ---------- Post added 03-26-15 at 11:23 PM ---------- Originally posted by rawr The lamp will probably work nicely to kill fungus too, if need be. Wonder would it cook Mushrooms ? lol ! https://www.pentaxforums.com/forums/images/smilies/lol.png

03-27-2015, 06:52 AM	#6
k0og Site Supporter Join Date: Nov 2008 Location: Rolla, Missouri Photos: Gallery \| Albums Posts: 699	I'm glad to see this thread - and confirmation from others that it works. I bought one of these lamps about a year and a half ago and used it on two yellowed Super-Takumars (50mm f1.4 and 35mm f2) and it worked for me. By the way, I use the lamp at my work bench and it is convenient for working on small things because of the directed light. It's a good price for a lamp like this! -Joe-

03-27-2015, 08:56 AM	#7
narual Veteran Member Join Date: Jun 2013 Location: South Bend (Notre Dame), Indiana Photos: Gallery \| Albums Posts: 1,988	Oh wow. I have several of these, plus the clamp version. I bought them in my apartment when I was working away from home for a few months and then brought them home with me when I started working remotely. My wife and I use two of the clamp ones as reading lights since our bed is in the middle of a round room and we couldn't do wall mounted lights, and the headboard is made of metal tubes, so couldn't screw lights into that, either. Aside from the two we use as bedroom reading lights, the rest I mostly use when I'm playing with macro. I have an apparently discontinued ikea white glass desk, and they're great companions to that -- I can clamp the clamp ones onto the edge and light it up from beneath and use the desktop ones all around the object. They even do a decent job making jewelry sparkle. They're so tiny that they don't get in the way, the gooseneck is nice and does a good job keeping them in place... and now you can use them to clean old lenses, too?

03-27-2015, 09:43 PM	#8
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Fiddler and left it about 1/8" inch above the Glass for 24hours. Only 24 hours? That is very cool! I only have a couple of yellowed lenses (both non-Asahi), but the thought of baking them in full sun does not appeal to me. Steve

03-28-2015, 07:53 AM	#10
Stavri Veteran Member Join Date: Aug 2014 Location: at a Bean & Leaf Photos: Albums Posts: 1,832	Cheap uv sanitizers work well in removing yellowing on radioactive elements. I use them routinely to kill/prevent fungus and for general maintenance

11-16-2020, 05:09 AM	#12
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485	I'm sure that for psychological reasons it's nice to remove the yellow tint from a lens. However, does yellowing significantly change the color of the image? If it does, some photos may benefit from a warmer glow. If not, why bother?

11-16-2020, 05:11 AM	#13
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,751	Originally posted by psoo I'm sure that for psychological reasons it's nice to remove the yellow tint from a lens. However, does yellowing significantly change the color of the image? If it does, some photos may benefit from a warmer glow. If not, why bother? it does change the image - some like the image with and some like it without the yellowing....

11-16-2020, 05:12 AM	#14
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,751	I use a different lamp to get the yellow out of my thoriated lenses: amazon.com: UV LED Black Light, HouLight High Power 10W LED Blacklight Flood Light IP65-Waterproof (85V-265V AC) for Blacklight Party Supplies, Neon Glow, Glow in The Dark, Birthdays, Blacklights, Curing: Home Improvement?tag=pentaxforums-20&

11-16-2020, 10:04 AM	#15
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by psoo I'm sure that for psychological reasons it's nice to remove the yellow tint from a lens. However, does yellowing significantly change the color of the image? If it does, some photos may benefit from a warmer glow. If not, why bother? The short answer is yes. Yellow is not a very good description for the discoloring. It is closer to tobacco stain in tint. There is also the matter that it is due to a disruption of the physical structure of the glass at the molecular level with attendant change in refractive character. (At least that is the theory.) My experience as well as that of others is an improvement in optical performance when cleared. Of course, YMMV. Steve