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fates
02-15-2011, 22:49
Hi all, just wanted to share the absolute fastest way I have found to clear up the yellowing of lenses due to rare earth content. I've cleaned up several Takumars and now a 50/2 Wetzlar rigid 'Cron with this lamp. After witnessing the speed in which it just cleaned up this Leica beauty from 1970, I was compelled to share this technique. For whatever reasons, it is able to clear up the yellowing of lens FAST. Like in all of 24 hours. Not a week of sitting in the windowsill trying to harness the sun.


So here's the secret tool.


The JANSJÖ work lamp from Ikea. Item number 101.287.34
It's an LED unit, but evidently puts out a highly focused beam of UV light that you can bend down right into the barrel of your lens. Seriously this thing works awesome. I've tried other UV bulbs to some good results but still those take days to undo the yellowing of decades of the radioactive breakdown. This lamp will cure it overnight. 2 nights, and you're back to like new.


Hope this is helpful to someone... other than Ikea's lamp sales.


http://nortega.com/wp-content/uploads/2011/02/jansjo-work-lamp_for_clearing_yellowed_lenses.jpg

surfer dude
02-16-2011, 01:22
Sorry, but for the life of me I can't understand why people would want to destroy the yellow coating on these lenses.

Yes, they are slightly radioactive, but they aren't about to produce three headed fish or make you glow in the dark. They are also totally unique in belonging to a time and place, and this is of value to many people. Also, the yellow itself adds a certain unique dimensionality to the image.

If you don't want the yellow, buy some other lens, but why destroy the rare existing ones?

pobe
02-16-2011, 01:25
I thought this was the fastest way: http://web.aanet.com.au/bayling/repair.html :)

Sonnar Brian
02-16-2011, 01:30
Sorry, but for the life of me I can't understand why people would want to destroy the yellow coating on these lenses.

Yes, they are slightly radioactive, but they aren't about to produce three headed fish or make you glow in the dark. They are also totally unique in belonging to a time and place, and this is of value to many people. Also, the yellow itself adds a certain unique dimensionality to the image.

If you don't want the yellow, buy some other lens, but why destroy the rare existing ones?


The Yellowing of the glass is from radiation damage from the radioactive Thorium. It was not made into the glass, and is not a yellow coating. The lens performs much more naturally with it gone.

the IDIOT that smashed the thorium lens- let's hope he did not ingest any of the particles as it will destroy your stomach lining.

Sonnar Brian
02-16-2011, 01:33
The Rigid Summicron does not use Thorium. The early Collapsible Summicrons, serial number under "About" 1050000 use it, and i have three of them.

The yellowing in a Rigid Summicron is from the Canadian Balsam turning yellow with time. I have never tried bleaching it out, please report the results with it.

surfer dude
02-16-2011, 01:36
OK Brian I stand somewhat corrected about it not being a coating, yet the yellowing DOES give unique properties - if you want a lens to perform naturally, why buy an interesting lens like this and then take away the very thing that makes it interesting?

Sonnar Brian
02-16-2011, 01:40
Have you ever used a Collapsible Summicron AFTER it has been bleached clear?

If you shoot just black and white, it is like having a yellow filter attached. So- you can always put a yellow filter on a lens and get the same result.

You have to bleach out the Thoriated Glass to get the filter off. It is well worth it, and you can always use a yellow filter for B&W.

I should add- I have one at Focalpoint now for polishing and getting a new front coating. It was opaque when I traded for it. A second was picked up in a trade for a Summitar and cash, because the owner wanted to shoot color. Picked up the third on a Leica IIIf, probably been on it since 1952.

For interesting: it is the low dispersion qualities of thoriated glass that make the lens interesting, at least to me. Not the radiation damage.

Roger Hicks
02-16-2011, 01:44
OK Brian I stand somewhat corrected about it not being a coating, yet the yellowing DOES give unique properties - if you want a lens to perform naturally, why buy an interesting lens like this and then take away the very thing that makes it interesting?
Dear Phil,

Alternatively, why not take it back to the state it was in when it was new?

Taking your argument far further than you would, why repolish a scratched lens? If you think the scratches make it interesting, leave 'em; if not, why not restore it? And bear in mind that the restoration is fuly reversible. Just leave it for another few decades...

Cheers,

R.

Roger Hicks
02-16-2011, 01:46
The Rigid Summicron does not use Thorium. The early Collapsible Summicrons, serial number under "About" 1050000 use it, and i have three of them.

The yellowing in a Rigid Summicron is from the Canadian Balsam turning yellow with time. I have never tried bleaching it out, please report the results with it.

Dear Brian,

No, surely it was Wetzlar balsam in those days...

(I don't do smileys, but those who like them can imagine one.)

Cheers,

R.

surfer dude
02-16-2011, 01:48
But Brian my point is, that bleach it and an historical oddity is no more. If you don't want the yellow filter effect all the time, buy any other lens that does not have the Thorium thingy. The OP seems to be running a production line of "fixing" the unique properties out of these lenses - why doesn't he just buy lenses that don't have the "problem" (or unique attribute) in the first place.


And no, I have never used one. I have never used a collapsible Summicron at all.

surfer dude
02-16-2011, 01:54
Dear Phil,

Alternatively, why not take it back to the state it was in when it was new?

Taking your argument far further than you would, why repolish a scratched lens? If you think the scratches make it interesting, leave 'em; if not, why not restore it? And bear in mind that the restoration is fuly reversible. Just leave it for another few decades...

Cheers,

R.

Hi Roger,

Well, why buy a scratched lens if you don't want a scratched lens (unless you can't afford an unscratched one in which case you are going to have to pay more for it to be repaired blah blah).

Besides which, there are many scratched/unscratched lenses but, as I said, these are historical oddities that belong to a time and place.

I must admit that I didn't know the Thorium would re-zap the lenses over time but - why do it if you don't want THAT lens for its individual properties?

Sonnar Brian
02-16-2011, 01:54
I am buying one of these lamps for myself!

Much better than leaving in the Sun to cure. I have a Collapsible Summicron that was sunbleached, before I received it. The grease was like Tar, the focus was impossible. I relubed it. I switched to a UV lamp after that. Worked decently.

As far as restoring lenses and cameras to their original and intended working condition, that is the point of camera repair. Radiation Damage in glass is an undesirable side-effect of the materials chosen for their construction and restoring them to their intended state is always desirable.

Sonnar Brian
02-16-2011, 02:05
too funny.

I know a faster way to cure the Radiation Damage. My Boss told me to just shine a LASER down the glass, that would cure it. That was several years ago. Not many people have UV LASERS though. I took his word for it, did not try it.

sevo
02-16-2011, 02:14
Not many people have UV LASERS though.

And even less people will have a soft UV LASER. The common excimer LASERS probably will not do, given that they have a hard spectrum and high power UV-C lamps are not effective either.

monochromejrnl
02-16-2011, 03:36
OK Brian I stand somewhat corrected about it not being a coating, yet the yellowing DOES give unique properties - if you want a lens to perform naturally, why buy an interesting lens like this and then take away the very thing that makes it interesting?


I see this as being no different than sending a vintage lens out for a CLA. Would you buy a vintage lens with haze and fungus and consider cleaning it detrimental to its unique character?

rxmd
02-16-2011, 03:52
Well, why buy a scratched lens if you don't want a scratched lens (unless you can't afford an unscratched one in which case you are going to have to pay more for it to be repaired blah blah).

Well if there was a way to unscratch lenses that only involved shining UV light down them and that's it, you can bet that I'd buy a lot of scratched lenses.

Yellowing is basically just an easily remedied form of damage. Historically accurate decomposition largely doesn't do anything for me photography-wise. Leather goes bad over time, too, but when buying a folder I still prefer one with a good bellows over one with an authentically decomposed one.

radiocemetery
02-16-2011, 03:56
Thanks for the post and information, fates. I am going to order one of these and besides I can use the "work Lamp" aspect too. My eyes need all the help they can get!

Arjay
02-16-2011, 04:03
I thought this was the fastest way: http://web.aanet.com.au/bayling/repair.html :)
You sure have a strange sense of humor...

Ronald M
02-16-2011, 04:06
The yellow makes it worthless for color pics imparting a yellow brown cast. That is why people want it gone.

Does sunlight permanently fix the yellow or at least for a year?

I once got a yellowed summicron. Was in absolute factory new mint perfect condition otherwise. What a shame as I returned it.
It was to be a lens for my iii f,

sevo
02-16-2011, 04:27
Does sunlight permanently fix the yellow or at least for a year?


As the radioactive decay does not stop, the lens will over the course of time go yellow again.

The Standard Deviant
02-16-2011, 04:39
As the radioactive decay does not stop, the lens will over the course of time go yellow again.

It will eventually stop when all the thorium atoms have decayed. You may wait a long time as the time for half to decay is about 14 billion years, then the next quarter is 14 billion years, then the next eighth is another 14 billion years, etc...

hans voralberg
02-16-2011, 04:41
Damn there's no IKEA where I live, still very good info.

Roger Hicks
02-16-2011, 05:32
Damn there's no IKEA where I live, still very good info.
Dear Hans,

There might be, sometime in the next in 14 billion years...

Cheers,

R.

Roger Hicks
02-16-2011, 05:37
Hi Roger,

Well, why buy a scratched lens if you don't want a scratched lens (unless you can't afford an unscratched one in which case you are going to have to pay more for it to be repaired blah blah).

Besides which, there are many scratched/unscratched lenses but, as I said, these are historical oddities that belong to a time and place.

I must admit that I didn't know the Thorium would re-zap the lenses over time but - why do it if you don't want THAT lens for its individual properties?

Dear Phil,

There are no unyellowed thoriated lenses, unless they've been bleached -- so bleaching one makes it MORE unusual in 2011. Why can't you buy a lens for the individual properties it had when it was new, instead of the individual properties (which many find undesirable) resulting from what amounts to an unforeseen design fault?

Cheers,

R.

maddoc
02-16-2011, 05:52
And even less people will have a soft UV LASER. The common excimer LASERS probably will not do, given that they have a hard spectrum and high power UV-C lamps are not effective either.

... been here, done that. :) Just to cure a slightly hazy Summitar lens that now shows heavy signs of element separation after the UV light destroyed the cement... :bang:

dogberryjr
02-16-2011, 06:15
The yellow makes it worthless for color pics imparting a yellow brown cast. That is why people want it gone.

I don't completely agree with this. I have a Canon 55mm 1.2 AL that is quite yellowed and I loved it for Kodachrome, especially with red subjects. Of course, now that's gone, so I'll have to try it out on some other stock. I may end up trying to clear it after all.

Sonnar Brian
02-16-2011, 06:23
The Canon 58/1.2 used Thorium Glass. I did not know the 55/1.2 also used it. Most yellowing that people see in older lenses is from the Balsam yellowing.

Yellowing in the thorium lenses is much more extreme, looks like a Y1 filter. It is miserable with color film. Of course with Digital, you can try changing the white balance to Tungsten to fix it.

We had some lamps used for UV cured Epoxy. I'll have to find out what wavelength they are.

dogberryjr
02-16-2011, 06:29
The Canon 58/1.2 used Thorium Glass. I did not know the 55/1.2 also used it. Most yellowing that people see in older lenses is from the Balsam yellowing.

Yep, it does. 7.5 μSV/h (http://photo.net/canon-fd-camera-forum/00NufL), whatever the hell that means.

Jack Conrad
02-16-2011, 06:30
Another thing about the yellowed lenses.

I've had a couple Takumar 50/1.4's and comparing a clear lens to
a yellowed one, the clear one was a full stop faster. At 1.4, given the same dim indoor lighting conditions my DSLR wanted to shoot at 1/30 with the clear lens and 1/15 with the yellowed one.
In other words, the yellowing reduces the amount of light reaching the film by a stop or possibly even more depending on how bad the yellowing has become.

So, by all means you'll be doing yourselves a favor clearing those great old lenses.

Roger Hicks
02-16-2011, 06:34
The Canon 58/1.2 used Thorium Glass. I did not know the 55/1.2 also used it. Most yellowing that people see in older lenses is from the Balsam yellowing.

Yellowing in the thorium lenses is much more extreme, looks like a Y1 filter. It is miserable with color film. Of course with Digital, you can try changing the white balance to Tungsten to fix it.

We had some lamps used for UV cured Epoxy. I'll have to find out what wavelength they are.

Or indeed downright brownish, if you leave it long enough. I assume you have a pre-1950 Aero Ektar swilling around somewhere?

(Preferably not under the bed. Conversation between a friend and a third party: Third party, "How radioactive are they?" Friend, "Not very, but you wouldn't want to store them under the bed." Friend, reporting story to me: "He went a bit pale. He'd been storing five under his bed.")

Cheers,

R.

fates
02-16-2011, 12:46
The Rigid Summicron does not use Thorium. The early Collapsible Summicrons, serial number under "About" 1050000 use it, and i have three of them.

The yellowing in a Rigid Summicron is from the Canadian Balsam turning yellow with time. I have never tried bleaching it out, please report the results with it.

I have a made in Germany Wetzlar with a 24331XX serial. It's yellowing was very much like the Thorium (I've read Lieca denied using thorium (http://leica-users.org/v01/msg15837.html), but then later admitted that they did) yellowing... actually, let's call it "monkey sh*t browning & dark clouding" so people don't confuse this process with removing desirable properties. A yellow or center filter is vastly superior to the decayed glass. Like others have said the discoloration will return. Might take a decade+ tho...

It cleaned up faster than a Takumar, but it is also 1/3 the surface area. 2 days of exposure and it is crystal clear again, there's no discoloration at all. I've only seen horrible results of Balsam sliding out, and this really looks... well looked like Thorium yellowing. Now I'm wishing I had documented the process this time.

I thought this was the fastest way: http://web.aanet.com.au/bayling/repair.html :)

Dear god, somebody please contact this bloke and tell him to revamp his website to not encourage people to:
destroy the best still photo lenses that behave like cine taking lenses ever made. They have such great long barrel throws and are super smooth. As good as Zeiss Cine mechanisms.
NEVER do this and poison themselves.What a tool.

Sonnar Brian
02-16-2011, 13:29
A Summicron with a serial number that late is well past the use of Thorium Glass. I have taken apart 8 or so of this series Summicron.

However: it is possible that the lens has radiation damage, depends what it was used for in the past. I've locked cameras into a vacuum chamber with radioactive elements before.

JFH
02-16-2011, 13:36
Not to divert the OP's original intent, but for my MC Rokkor 28mm f2.5 SI lens with a yellow/brown internal element, I found that simply screwing on an 82A filter seems to restore good color performance... and it's really fast, goes on in less than 15 seconds... :)

charjohncarter
02-16-2011, 13:41
What kind of bulb is in the IKEA lamp?

sevo
02-16-2011, 13:51
It looks very much like a Seoul P4 LED.

charjohncarter
02-16-2011, 15:12
It looks very much like a Seoul P4 LED.

Thanks.....

fates
02-16-2011, 17:29
The bulb is pretty much encased in the lamp, and I can't see a quick way to pull it out and read any markings.

A Summicron with a serial number that late is well past the use of Thorium Glass. I have taken apart 8 or so of this series Summicron.

However: it is possible that the lens has radiation damage, depends what it was used for in the past. I've locked cameras into a vacuum chamber with radioactive elements before.

Yeah, I was surprised to see a rigid 1970 lens that appeared to have Thorium "Monkey Sh*t Browning", but I figured I was new to Leica glass ownership... and what I don't know can fill an 80 gallon drum. I'll post back in another ten years and let everyone know how the discoloration is proceeding. ;)

I was so apt to clear it up, I didn't think too much of it's possible odd nature, and in retrospect should have documented the process. :bang:


Not to divert the OP's original intent, but for my MC Rokkor 28mm f2.5 SI lens with a yellow/brown internal element, I found that simply screwing on an 82A filter seems to restore good color performance... and it's really fast, goes on in less than 15 seconds... :)

Sure, if you like loosing light, can't stand to put the camera down for 6-12 hours (or attach another lens in the interim), or part with the 5.99 USD for a lamp... :p

Wow, I thought most shooters liked their glass clear, non-tinted, and as fast as it was designed to be?

fates
02-22-2011, 22:15
Originally Posted by hans voralberg http://www.rangefinderforum.com/forums/themes/graphite/buttons/viewpost.gif (http://www.rangefinderforum.com/forums/showthread.php?p=1549784#post1549784)
Damn there's no IKEA where I live, still very good info.

Dear Hans,

There might be, sometime in the next in 14 billion years...
Cheers,
R.


Roger,
I just wanted to say this was one of the funniest posts ever... at least to me. Really cracked me up!

ampguy
02-23-2011, 07:44
This was my reason for deciding against an old Pen 38/40/42 lens as they will give a brown cast to the images unless cleaned of the light.

I have a low power UV laser, but it's not powerful enough to clean a lens, but is useful for being able to tell if a vintage lens is blocking UV light or not.


The yellow makes it worthless for color pics imparting a yellow brown cast. That is why people want it gone.

Does sunlight permanently fix the yellow or at least for a year?

I once got a yellowed summicron. Was in absolute factory new mint perfect condition otherwise. What a shame as I returned it.
It was to be a lens for my iii f,

michel v
03-03-2011, 09:46
Hello,

I bought this very lamp yesterday and have let my Takumar 50 1.4 bask in its light for over 20 hours.
I really should have taken accurate pictures of the lens before the process, because I'm not sure that it was actually bleached when I look at it now.

Just in case, would a serial number of 1725xxx still fit with the period when they used thorium?
Or is shining LED light in it useless?

Thanks.
(And I just noticed my Pen F 40mm is a little bit yellow too. Did every lens in this serie use thorium?)

fates
03-03-2011, 10:41
Hmm that serial should be in the range, and it should work. Unless the lamp now ships with a non-UV bulb in it?

How yellow... er, monkey sh*t brown is your lens currently? Some lenses will cure faster than others. Are you seeing no progress at all? Are you getting the head of the lamp right up against the glass?

Gabriel M.A.
03-03-2011, 10:52
the IDIOT that smashed the thorium lens- let's hope he did not ingest any of the particles as it will destroy your stomach lining.

It's natural selection vs. the "who cares!" crowd. ;)

unixrevolution
03-03-2011, 11:47
the IDIOT that smashed the thorium lens- let's hope he did not ingest any of the particles as it will destroy your stomach lining.

Given what he did to that poor defenseless Takumar, I'm hoping he did ingest just a little. Karmic balance.

fates
03-03-2011, 12:32
Did anyone ever contact that guy and ask him to update his site? Dangerous to encourage kids to do this... by which I mean, ruining perfectly good Takumars.

ampguy
03-03-2011, 16:10
besides the Rokkor and Takumars as mentioned above, the fast Pen 42/1.2 (but not the 38/1.8), Nikkor 50 HC (maybe just some?) seem to have yellowing issues over time.

Sonnar Brian
03-03-2011, 16:13
The Nikkor-HC 50/2 - probably the Canadian Balsam yellowed, not from use of Thorium. Thorium is a Heavy Element- did not realize it was element 90 until Nikki did her homework tonight.

I love Heavy Metal.

ampguy
03-03-2011, 16:19
You are probably right, I got some info. from the posting here:

http://forum.getdpi.com/forum/showthread.php?t=18549&page=5

(way down on post # 245)

where the tester kept the white balance constant. Of course, his sample # is small, but I have heard of some Pens and of course the Takumars having Thorium elements, as well as very early Crons, etc.


The Nikkor-HC 50/2 - probably the Canadian Balsam yellowed, not from use of Thorium. Thorium is a Heavy Element- did not realize it was element 90 until Nikki did her homework tonight.

I love Heavy Metal.

Sonnar Brian
03-03-2011, 16:33
My Thorium Summicron is on it's way back from Focalpoint. I had the front surface polished and recoated. I will see how it compares with the later version.

I am still not comfortable putting a Hot-Glass lens on a Digital Camera. Maybe I'll take the lens off of an old Digital, put the Thorium lens over the sensor, and see if damage occurs.

ampguy
03-03-2011, 16:39
After testing a lot of lenses and old stuff around with a geiger counter, I'm not into radioactive lenses at all these days. First instincts are to hold them up to the eyes or leave out, and very close, some of these are still pretty hot, and will be for awhile.

My Thorium Summicron is on it's way back from Focalpoint. I had the front surface polished and recoated. I will see how it compares with the later version.

I am still not comfortable putting a Hot-Glass lens on a Digital Camera. Maybe I'll take the lens off of an old Digital, put the Thorium lens over the sensor, and see if damage occurs.

rxmd
03-03-2011, 17:40
My Thorium Summicron is on it's way back from Focalpoint.

The real question is - does the thorium make it a Summicron 90?

michel v
03-04-2011, 02:14
Hmm that serial should be in the range, and it should work. Unless the lamp now ships with a non-UV bulb in it?

How yellow... er, monkey sh*t brown is your lens currently? Some lenses will cure faster than others. Are you seeing no progress at all? Are you getting the head of the lamp right up against the glass?

Just checked on several localized Ikea websites. The only difference is the item number for this lamp, but it seems to only be there for regions (ie. same item for US & Can, and the same for all Europe). The only possibility of difference left would be European regulations forcing Ikea to use a different LED.

As for my lens, its yellow is similar to that exhibited by yours after 5 hours of bleaching.
And I did not put the lamp right against the frontal element of the lens, but 10 centimetres (4 inches) away, as I tried to bleach two lenses at the same time. Does this make a big difference?

fates
03-04-2011, 09:28
I would get the tip of the light right against the front element (don't rub it around, be careful) , leave for a day then switch to the rear element. Having such distance may be your problem... that and do one lens at a time.

Zathros
03-04-2011, 10:13
Sorry, but for the life of me I can't understand why people would want to destroy the yellow coating on these lenses.

Yes, they are slightly radioactive, but they aren't about to produce three headed fish or make you glow in the dark. They are also totally unique in belonging to a time and place, and this is of value to many people. Also, the yellow itself adds a certain unique dimensionality to the image.

If you don't want the yellow, buy some other lens, but why destroy the rare existing ones?

Phil, most owners of the yellowed lenses do not think that the discoloration is a good thing. When these lenses were new, the glass was quite clear. When I bought my Takumars, used on ebay, I was unaware that certain lenses had a tendency to turn yellow and was very disappointed with the yellowed lenses. As a result, I have almost never used these lenses. Most people who are bleaching the yellow out of the lens are doing so to restore their lens back to its original state.


I now have, thanks to the OP, an inexpensive and efficient way of salvaging lenses that were previously not usable for me.

Zathros
03-04-2011, 10:21
Hi all, just wanted to share the absolute fastest way I have found to clear up the yellowing of lenses due to rare earth content. I've cleaned up several Takumars and now a 50/2 Wetzlar rigid 'Cron with this lamp. After witnessing the speed in which it just cleaned up this Leica beauty from 1970, I was compelled to share this technique. For whatever reasons, it is able to clear up the yellowing of lens FAST. Like in all of 24 hours. Not a week of sitting in the windowsill trying to harness the sun.


So here's the secret tool.


The JANSJÖ work lamp from Ikea. Item number 101.287.34
It's an LED unit, but evidently puts out a highly focused beam of UV light that you can bend down right into the barrel of your lens. Seriously this thing works awesome. I've tried other UV bulbs to some good results but still those take days to undo the yellowing of decades of the radioactive breakdown. This lamp will cure it overnight. 2 nights, and you're back to like new.


Hope this is helpful to someone... other than Ikea's lamp sales.


http://nortega.com/wp-content/uploads/2011/02/jansjo-work-lamp_for_clearing_yellowed_lenses.jpg

Thanks for posting this, I have two yellowed Takumars, 50mm and 35mm that I can now clean up and use.

Mike

Seele
03-04-2011, 20:14
Phil, most owners of the yellowed lenses do not think that the discoloration is a good thing. When these lenses were new, the glass was quite clear. When I bought my Takumars, used on ebay, I was unaware that certain lenses had a tendency to turn yellow and was very disappointed with the yellowed lenses. As a result, I have almost never used these lenses. Most people who are bleaching the yellow out of the lens are doing so to restore their lens back to its original state.


I now have, thanks to the OP, an inexpensive and efficient way of salvaging lenses that were previously not usable for me.

Zathros,

To my mind, it seems that Phil believed the yellow tint in the glass was an original feature of a lens, as intended by the designer, so that an attempt to remove it would be making it non-original.

Zathros
03-04-2011, 21:09
Zathros,

To my mind, it seems that Phil believed the yellow tint in the glass was an original feature of a lens, as intended by the designer, so that an attempt to remove it would be making it non-original.

True,

But after several other members explained why they would bleach the lens, he still insists that one should not bleach out the yellow, saying that they should get another lens instead.

I am interested in using a lens that functions as its designer intended, not in preserving, as Phil calls it, a "historical oddity". When these lenses were designed, the designers never intended for them to turn yellow after a few decades. This is an unintended side effect of the thoriated glass used in some designs. The designers were using the rare-earth glass because it allowed them to design fast, highly corrected lenses with the technology of the day.

I own two of the affected Takumars, a 50mm f1.4 Super Takumar and a 35mm f2.0 Super Takumar that I bought used on ebay a few years ago. At the time, I was unaware of the tendency of these particular Takumars to turn yellow with age. When I received the lenses, I was disappointed with them, but kept them because I felt that the sellers were not trying to rip me off. Since I was shooting a lot more color back then, I did not find these yellowed lenses very useful. I also did not like looking through the viewfinder with these lenses on the camera. I made do with slower lenses.

When I found out that this yellowing was reversible with exposure to UV radiation, I decided to try it at some point in time.

I consider the bleaching with UV light to be an act of restoration, not alteration. I believe that my lenses will finally perform as Pentax intended them too, once again, after I give them the UV treatment. I never got around to doing this before, since I was not comfortable with leaving the lens in the window for a few weeks while waiting for the sun to do its job. I feel that the OP's method is an elegant solution to the problem. Cheap too!

To quote Brian Sweeney, in post #12 of this thread;

"As far as restoring lenses and cameras to their original and intended working condition, that is the point of camera repair. Radiation Damage in glass is an undesirable side-effect of the materials chosen for their construction and restoring them to their intended state is always desirable."

I think Phil just doesn't get it. His comments seem rather silly to me.

sevo
03-05-2011, 00:55
The only possibility of difference left would be European regulations forcing Ikea to use a different LED.


So far, LEDs are only capable of putting out very, very near visible UV - and white light (fluorescent) LEDs emit pretty much nothing invisible at all. So there is nothing that could be regulated there. It is more likely that Ikea, cheapskates as they are, use low-grade LEDs of poor colour consistency, where some will be leaking blue from the LED proper while others have too much of a fluorescent cover and a corresponding excessive yellow tint. Something like that would be perfectly in line with the notoriously poor colour rendering from Ikea CFL lamps.

michel v
03-05-2011, 01:41
I never got around to doing this before, since I was not comfortable with leaving the lens in the window for a few weeks while waiting for the sun to do its job.

That's what I first did with my 50mm. The problem is, at that time the sun only shone for a day, then I forgot about it, then rain happened, then I remembered I had a lens on the window!
To my surprise, the lens still works. I think rain might have damaged the coating though, and that in some years fungus might appear… But oh well, still trying to bleach it now. :)

jplbound
03-06-2011, 16:17
Hi all, just wanted to share the absolute fastest way I have found to clear up the yellowing of lenses due to rare earth content. I've cleaned up several Takumars and now a 50/2 Wetzlar rigid 'Cron with this lamp. After witnessing the speed in which it just cleaned up this Leica beauty from 1970, I was compelled to share this technique. For whatever reasons, it is able to clear up the yellowing of lens FAST. Like in all of 24 hours. Not a week of sitting in the windowsill trying to harness the sun.


So here's the secret tool.


The JANSJÖ work lamp from Ikea. Item number 101.287.34
It's an LED unit, but evidently puts out a highly focused beam of UV light that you can bend down right into the barrel of your lens. Seriously this thing works awesome. I've tried other UV bulbs to some good results but still those take days to undo the yellowing of decades of the radioactive breakdown. This lamp will cure it overnight. 2 nights, and you're back to like new.


Hope this is helpful to someone... other than Ikea's lamp sales.


http://nortega.com/wp-content/uploads/2011/02/jansjo-work-lamp_for_clearing_yellowed_lenses.jpg








The nearest Ikea is 250 miles away!!! They do not offer this online. Strike two; I guess I will have to use a black light.:mad:

KoNickon
03-06-2011, 17:00
Someone above mentioned the Rokkor 28/2.5MC as having the discoloration (and I like the suggestion about using a color correction filter for it). I have that same lens and discoloration, but someone else (Brian?) indicated that discoloration is likely due to the lens cement. I have a Nikkor 35/1.4 that's discolored as well. I infer that this IKEA lens won't work on the balsam, correct? Too bad if that's so, since I figure having someone like Focal Point decement and recement a lens would be big bucks.

KoNickon
03-06-2011, 17:05
Sorry, meant to say "IKEA lamp."

rxmd
03-06-2011, 20:49
The nearest Ikea is 250 miles away!!! They do not offer this online. Strike two; I guess I will have to use a black light.:mad:

It's not like this is a magic lamp or something. Just buy the cheapest Chinese white-light LED lamp you can find. By virtue of being cheap, it will do the job of emitting near-UV.

rxmd
03-06-2011, 20:54
I think Phil just doesn't get it. His comments seem rather silly to me.

I think he got out of this thread two weeks ago, so whether he "gets it" is not the question anymore.

neilvan
03-07-2011, 18:47
Thanks for posting this, my OM 55mm f1.2 will be like a new lens! I have an Ikea just down the road...

Zathros
03-07-2011, 19:12
That's what I first did with my 50mm. The problem is, at that time the sun only shone for a day, then I forgot about it, then rain happened, then I remembered I had a lens on the window!
To my surprise, the lens still works. I think rain might have damaged the coating though, and that in some years fungus might appear… But oh well, still trying to bleach it now. :)

I may be mistaken, but I've heard that the UV radiation will also kill fungus spores. Anybody know anything about this?

vha
03-21-2011, 12:14
So far, LEDs are only capable of putting out very, very near visible UV - and white light (fluorescent) LEDs emit pretty much nothing invisible at all. So there is nothing that could be regulated there. It is more likely that Ikea, cheapskates as they are, use low-grade LEDs of poor colour consistency, where some will be leaking blue from the LED proper while others have too much of a fluorescent cover and a corresponding excessive yellow tint. Something like that would be perfectly in line with the notoriously poor colour rendering from Ikea CFL lamps.

Got my hands on a European version of the lamp, and it looks to me that ikea have been cheap with the foot of the lamp too (at least the weight inside it) , and since Ikea in general is cheap (either a good or a bad thing) I assume the difference for US and mine is that mine has a europlug/CEE 7/16/type C power-plug on the adapter and is 220V.

Will try the lenscleaning later this week.

vha

rogerzilla
03-21-2011, 13:34
I may be mistaken, but I've heard that the UV radiation will also kill fungus spores. Anybody know anything about this?

The thorium probably kills them anyway. An anecdote from Peter at CRR Luton; when he was serving in the Far East they had a load of binoculars shipped over from England and within a few weeks most were completely fogged up by fungal growth in the hot, humid environment.

Except the ones with thorium glass...

sevo
03-22-2011, 00:38
The thorium probably kills them anyway.

Probably not - there are fungi inside the Chernobyl reactor building actually living on radiation as their only source of energy.

Spores would get killed by ionizing UVC radiation - but that is not the same range as the UVA or visible violet used for bleaching. So that that would be a separate treatment. Caution: You must use a proper sterilizing apparatus, never operate a bare UVC source, it can make you blind and cause radiation burns.

bucs
03-22-2011, 01:08
Another thing about the yellowed lenses.

I've had a couple Takumar 50/1.4's and comparing a clear lens to
a yellowed one, the clear one was a full stop faster. At 1.4, given the same dim indoor lighting conditions my DSLR wanted to shoot at 1/30 with the clear lens and 1/15 with the yellowed one.
In other words, the yellowing reduces the amount of light reaching the film by a stop or possibly even more depending on how bad the yellowing has become.

So, by all means you'll be doing yourselves a favor clearing those great old lenses.

And I thought my spotmatic's meter was broken :bang: I checked my 50mm takumar just now and it is yellow. now i need to get one of those UV lamps

asparis
03-26-2011, 07:45
Bah! Went to the Ikea website. The JANSJO lamps appear in the catalog, but are not sold on-line. You can only buy them at the store, which in my case is about 20 miles away.

Is there any chance that a "Black" light would work? Or is that a completely different kind of UV?

filmtwit
10-02-2011, 09:31
Take lens and put it on an indoor window sill that gets a decent about of sunshine. The UV light will clear it up nice and natural in a few days.

gorbas
10-02-2011, 09:34
Hi Guys,
I'm hoping that somebody is still following this thread? There is my first result with Ikea LED light:
http://www.rangefinderforum.com/photopost/showphoto.php?photo=168190&ppuser=5518


I can't see "huge" difference between treated and untreated SMC Takumar's 1.4/50. The treated lens is definitely less yellow than untreated, but... Real test is going to be with Super Takumar 2/35 that is seriously affected by yellowing.
Goran
PS I have problem posting image here, If you can't see picture please try:
http://www.flickr.com/photos/[email protected]/6203881879/in/photostream

gorbas
10-05-2011, 15:50
Hi filmtwit,
As you know, we don't have much sunshine on Pacific northwest and my apartment is facing north, so Ikea LED light was very elegant solution.

Flat Twin
03-06-2012, 08:28
I read this thread a few weeks ago and got quite excited about the Ikea lamp. I have an early Nikkor N 35mm f1.4 that is quite yellow'd and I would love to clean it up.

Well after the usual annoying trip to Ikea I successfully picked up the lamp and it is now sat on my desk shining into the lens. Time will tell!

Initial thoughts are that the lamp emits quite a "warm" light not a white light.

I'll update with the results in a day or so!

Simon

drew.saunders
03-06-2012, 08:52
The JANSJÖ work lamp from Ikea. Item number 101.287.34



They're also only $10 (at least in the US). I use two for tabletop photography. Since I shoot B&W film, the color balance of LED doesn't bother me. These are really nice little lamps at a dirt-cheap price. IKEA also sells one with a clamp base that's much more expensive.

n5jrn
03-06-2012, 09:46
I am still not comfortable putting a Hot-Glass lens on a Digital Camera. Maybe I'll take the lens off of an old Digital, put the Thorium lens over the sensor, and see if damage occurs.

Natural thorium has a very long half-life, which means its rate of emission of radiation is very slow. So I wouldn't worry about radiation-induced sensor damage from occasionally using a lens with a thoriated element. If thoriated lenses spewed radiation like mad, they would never have been invented, because they would have fogged film.

From chasing around Wikipedia articles, most of its decay chain involves alpha and beta emission only. Such particles do not have much penetrating power; storing a thoriated lens in a sealed mason jar should be sufficient shielding. (Toss in a bag of dessicant to keep the fungus at bay.)

photografity
03-10-2012, 11:12
I happened to pick up a 1958 Jupiter-8 that has some yellow glass.... I have to admit, I liked the warm cast this puts on the images.
Now that I came across this thread, Is it safe to assume that this "yellow" is Thorium?

szpeter
03-09-2013, 23:15
I was really excited reading about such a simple tool for bleaching old lenses. I bought a Minolta PG 58 1.2 in nice condition, but the lenses were, well, not yellow, rather brown. The strength of discoloration did not only affect colors, but it must have definitely worsen light transmission, meaning the F1.2 position was close to F2 in reality.

No worries it is just question of few hours with Jansjö lamp and my lens should be like new. I paid a visit to Ikea and found a collection of Jansjö lamps. None had the Ikea product number mentioned before, but one looked exactly the same as described at the beginning of this thread. Since Ikea has a policy that they take everything back I took no risk by buying this version of Jansjö, which held the Ikea number: 602.137.82. I hoped that this is the Hungarian product lot of the same lamp (this was in Ikea Budapest, Hungary).

I put the lens to the lamp and started the process. After three days no change could be detected. I gave back the lamp to Ikea and was 100% compensated.

But the idea of using LED lamp for this purpose suggestedd that I should look around and give other type of LEDs a try. I have a Walther tactical spot lamp (http://www.midwayusa.com/product/143019/walther-tactical-pro-flashlight-led-bulb-aluminum-black), with 170 lumen LED beam, much stronger than Jansjö. I used a small 220V to 6V converter and some wires to maintain electric power for three days long, so 10-15 minutes DIY is needed. The Walther seems working with 5V too, so any smart phone mains converter can be used. This setup worked perfectly, after three days my lens was cured. Although it is a bit more expensive than Jansjö, but can be used widely for other purposes.

Conclusion is that it is worth trying strong LED torches before switching to UV.

Ernst Dinkla
03-10-2013, 00:55
Could not resist an Alpina UV bug killer action at the Makro here some years ago. 12 Euro for a nice near Braun/Dieter Rams design and I detest bugs. Used it and it did not kill any bugs, they probably prefer dirty, ugly places to die.
Then I liked to see what a Wray 2" f1.0 copy lens could do on an M4/3. as it is or with the front lens removed. Elements were near brown. I expected it would not be the last lens that had to be bleached. So I took the Alpina apart and removed all the High Voltage parts, kept the lamp and the casing. Put aluminium foil everywhere inside as a reflector and made sure no contact was made anywhere with the electricity. Put the Wray in that UV chamber and expected it would stay there for at least a night. After 4 hours the lens was crystal clear. The Alpina does not look so nice anymore though. I guess this thing was never a success as a bug killer. The only page that shows the Alpina JW9WA is this one and it carries another name. The lamp is a common UV CFL for bug killing.

http://www.conrad.ch/ce/fr/product/710001/?insert=D9&WT.mc_id=affiliate_tradedoubler_toppreise&utm_source=toppreise_fr&utm_medium=affiliation&utm_campaign=productfeed&utm_content=710001&tduid=4a2a2b78a66ec4e73caf8c49757198d5

Ernst Dinkla
03-10-2013, 01:05
Could not resist an Alpina UV bug killer action at the Makro here some years ago. 12 Euro for a nice near Braun/Dieter Rams design and I detest bugs. Used it and it did not kill any bugs, they probably prefer dirty, ugly places to die.
Then I liked to see what a Wray 2" f1.0 copy lens could do on an M4/3. as it is or with the front lens removed. Elements were near brown. I expected it would not be the last lens that had to be bleached. So I took the Alpina apart and removed all the High Voltage parts, kept the lamp and the casing. Put aluminium foil everywhere as a reflector inside and made sure no contact was made anywhere with the electricity. Put the Wray in that UV chamber and expected it would stay there for at least a night. After 4 hours the lens was crystal clear. The Alpina does not look so nice anymore though. I guess this thing was never a success as a bug killer. The only page that shows the Alpina JW9WA is this one and it carries another name. The lamp is a common UV CFL for bug killing.

http://www.conrad.ch/ce/fr/product/710001/?insert=D9&WT.mc_id=affiliate_tradedoubler_toppreise&utm_source=toppreise_fr&utm_medium=affiliation&utm_campaign=productfeed&utm_content=710001&tduid=4a2a2b78a66ec4e73caf8c49757198d5