5cm Summicron 1023xxx serial number coating color.

[kknox]

I have three 50 Summicrom lens from the late 50's & early 60's. I just received a 5cm LTM Summicron serial # 10231xx that has a slight yellow cast to the glass. I have seen this before is it the coating or the type of glass they used? The coating is not damaged.

 

[ferider]

An early version with radioactive glass.

 

[kknox]

So I need to call the haz-mat crew to come over and take it from me. No not really, will my color pics take on a yellow cast?

 

[Sonnar Brian]

The early Summicrons used Thorium Glass, including in the front element. You can "bleach it out" with a UV light, or direct sunlight. You need to set it in light for a few days. Sunlight will make the lens hot, and bake the grease. Make sure the exit of the glass is covered in foil to prevent the suns rays from setting something on fire. I had a friend that set some optics in the basement window and started a fire. He put it out before it got out of hand.

The pictures will take on that yellow cast. Great for B&W. If you are not interested in it as a collectible, you might consider trading it or selling it and buying a later one.

 

[kknox]

Is it a collectable lens? I know its a early Summicron

 

[Sonnar Brian]

Early Collapsible Summicron on Left, later Collapsible on right.

And yes- collectible. It's the first generation Summicron, used RADIOACTIVE glass, and uses Commas instead of decimal points in the F-Stop numbers...

It usually carries a ~$100 premium over a similar condition lens. You might want to see if someone wants to trade a mint glass Summicron for it. Or: do what I did, bleach the Yellow out and shoot with it. I received my lens after someone bleached it, but had to relube it.

 

[benmacphoto]

So I need to call the haz-mat crew to come over and take it from me. No not really, will my color pics take on a yellow cast?

I have one, and did some work with Velvia 50 and the results were very pleasing. A bit of a color cast but it was a nice warm glow. Try it out for yourself to see if you like the way it looks.

BTW the lens is great for black and white work.

 

[kknox]

Thank's everyone it should be fun to try.

 

[John Shriver]

Yeah, that almost certainly is an early radioactive one. Mine is 10241xx, and it definitely excites my Geiger counter, and the glass is tea-colored. I tried to bleach it with a UV light, but it was a UV C light, and I think the glass is opaque to that wavelength.

The glass is radioactive because it's 30% or more thorium. Well, some elements are (the flint glass).

It turns brown because that's what ionizing radiation does to glass. They can't use fiber optics in the tunnels at CERN due to this.

 

[SimonSawSunlight]

I have a #1167xxx M-mount collapsible summicron in very good condition. the glass seems to have a slight yellow-brownish tint as well if I look through it against a white surface.
my understanding was that, given the serial number and mount, this is a non-thorium version, am I wrong? or is it just dirty inside? 😀

 

[sevo]

I tried to bleach it with a UV light, but it was a UV C light, and I think the glass is opaque to that wavelength.

Right. You need a UV-A/UV-B light - the ones sold for nail polish hardening, insect light traps or desert zone vivarium lighting do best, but even decorative black light CFL lamps work better than UV-C (water sterilizing) ones.

Sevo

 

[Sonnar Brian]

SN 116x should not have Thorium in it. You are probably seeing haze or just the coating.

 

[SimonSawSunlight]

SN 116x should not have Thorium in it. You are probably seeing haze or just the coating.

that's what I thought. doesn't look like haze, so you're probably right about the coating 🙂 thanks

 

[John Shriver]

I have Summicron 1024XXX and it definitely is radioactive (verified with my Geiger counter), and is definitely tea-colored to look through.

I tried bleaching it with UV light, but the one I borrowed was UV-C, and had no effect over weeks of effort.

 

[kermaier]

What's the effect of the yellow-brown tint on a digital camera like the M8 or R-D1?
::Ari

 

[Sonnar Brian]

It will be like using a yellow filter.

I know this sounds weenee and illogical: Thorium Summicrons can fog film if left over it long enough. I'm not putting it on my M8. I have two of them, they stay on the film cameras.

 

[Ronald M]

It acts just like a yellow/brown filter making all color photos with that color cast, digi or film. On digi, you can shoot raw and make a preset to bring it back to neutral. Possibly you could do something to alter color bal in digi menue to offset yellow to blue and then do something with brown for JPEGS. This is in the form of a graph DEEP in Nikons menue. But then other lenses will be off color. Can`t advise on M9.

Return it to the seller as it is not worth fooling with as a user. Shame, someone sent me one all yellow, but in absolutely fresh factory condition otherwise. I returned it.

I hear they work as a yellow filter on B&W film.

The lens is not that great anyway, even if perfect. Get a rigid or DR or the last version of the 50 2.8. The last 2.8 will out perform the first sumi by a mile.

 

[kermaier]

It will be like using a yellow filter.

I know this sounds weenee and illogical: Thorium Summicrons can fog film if left over it long enough. I'm not putting it on my M8. I have two of them, they stay on the film cameras.

Yes, the question of the effects of radioactive decay on digital electronics crossed my mind as well. 🙂 Since I'm not shooting 35mm film anymore, but using an R-D1, the early collapsible 'cron may not be the best move for me.

I have a very clean Rigid Type I, which is great. Alas, I have a terrible weakness for beautifully made vintage lenses, and I have the opportunity to buy a super-clean 1020xxx range LTM collapsible 'cron. Despite having far too many lenses, especially in 50mm, I resist purchasing items I can't actually use -- my hoard is too random and well-worn to be considered a "collection". 😱 I guess if I feel the irrestible need for a collapsible Summicron, I should go for a later one, maybe in M-mount.

::Ari