Which lenses for an M are radioactive?

[dave lackey]

A current thread about Lanthanum and Thoirium has me wondering as I never thought about it before...

Which lenses are considered radioactive lenses?😕

And which ones should be stored away from people and not under your bed?😱

 

[kuzano]

I had a Bessa II with an APO Lanthar....

I had a Bessa II with an APO Lanthar....

And shortly after I got it, the doctor told me I could not impregnate my wife......

Or, maybe it was the vasectomy?

 

[dave lackey]

This is a serious question that I find odd no one has responded with a serious answer. 12 hours and not even a single serious answer with 114 thread views.

If this is a BS question that folks are tired of hearing, say so and I will not bother you anymore.

RFF has been very helpful in the past and I expected more from our knowledgeable people here. So what gives?

 

[sinetsin]

Take a look to this thread..
http://www.rangefinderforum.com/forums/showthread.php?t=70079

 

[rxmd]

Warning! Radioactive thread!

Radioactive lenses are nothing to worry about. The topic crops up every few months on photo forums. In practice taking your camera on a plane exposes it to more radiation than any radioactive lens ever will.

 

[gdi]

This is a serious question that I find odd no one has responded with a serious answer. 12 hours and not even a single serious answer with 114 thread views.

If this is a BS question that folks are tired of hearing, say so and I will not bother you anymore.

RFF has been very helpful in the past and I expected more from our knowledgeable people here. So what gives?

The most common is (I beleive) the early, pre 1,000,000 serial # Collapsible Summicron. I have heard that some Elmars used thorium, but I, personally, know of no definitive reference. And other manufacturers used it - Pentax, Canon, Kodak...

It might help if you indicate your interest in them - do you have one, want one, or wonder about their imaging qualities?

 

[dave lackey]

How about the LTM lenses?

Specifically, the Summarit and Industar lenses?

I would think it would be a good conversational piece if nothing else. It is a topic of research importance for me at the moment. Not that I am worried about it....but...I have read some literature about lengthy exposure to the eyes, etc. 😕

 

[gdi]

How about the LTM lenses?

Specifically, the Summarit and Industar lenses?

I would think it would be a good conversational piece if nothing else. It is a topic of research importance for me at the moment. Not that I am worried about it....but...I have read some literature about lengthy exposure to the eyes, etc. 😕

They are referring to eyepieces - telescope or movie cameras, I believe.

I had an LTM Summicron with thorium, but I don't know about the others - if the glass has turned yellow or brownish, it could contain it.

Here is a link...

http://www.orau.org/PTP/collection/consumer%20products/cameralens.htm

 

[ferider]

Hi Dave,

a good question, but I think you are getting few answers because people just don't know for sure. The collapsible Summicron (around serial 1Mio) and very late Summitar had Lanthanum and Thorium based glass. Where Thorium is radioactive.

Later lenses (like the early 35 Summilux) did include Lanthanum glass, but no Thorium, apparently.

Best,

Roland.

 

[dave lackey]

Hi Dave,

a good question, but I think you are getting few answers because people just don't know for sure. The collapsible Summicron (around serial 1Mio) and very late Summitar had Lanthanum and Thorium based glass. Where Thorium is radioactive.

Later lenses (like the early 35 Summilux) did include Lanthanum glass, but no Thorium, apparently.

Best,

Roland.

Thanks Roland! Now we're getting somewhere...

I have found no references to the Russian lenses yet, or for that matter, the '50s Summarit.

Is there any way to test lenses with a radioactivity monitor of some kind?

 

[colker]

this is the most bizarre thread on the internet NOW.

 

[Leigh Youdale]

The reason it's been such a secret and why there's no data on Russian lenses is that the CIA think it was a communist conspiracy in the 1950's to render all news photographers impotent and, with them being more worried about that than what was happening in the world, the Ruskies could march to world dominance unnoticed by the international press.

 

[dave lackey]

Bizarre?

This evidently has been discussed for years:

http://www.camerapedia.org/wiki/Radioactive_lenses

The problem with this article is it does not include the Leica lenses or any of a number of other lenses discussed previously on photo.net...

Bizarre? Maybe. Interesting...it is to me.

 

[Ron (Netherlands)]

From what I read, the only LTM FSU lens produced with Lanthanum is the Industar L/D 61. I have two, and must admit, they are quite a bit sharper than my other FSU lenses. Glass seems a bit yellowish.

 

[Beemermark]

I work in the nuclear industry and many of the 1950~1970 age lenses are "radioactive". So are a lot of things -ceramic plates, fire detectors, exit signs in buildings, wristwatches, - I could go all day but I think you get the point. You'll get more "radioactive" dose walking outside in Miami then you'll get in a year if sleeping with any of your lenses. The dentist should be your biggest concern.

 

[Beemermark]

BTW I have a third generation M mount 35 Summicron that sent the counter screaming. Had a major hassle getting it released from the power block.

 

[dave lackey]

So, if a counter can scream around one of these lenses...what would happen going through security at the airport?😛

 

[Mackinaw]

So, if a counter can scream around one of these lenses...what would happen going through security at the airport?😛

Nothing. I have a early concave-front element Canon FD 35mm F2.0 (with thorium) that goes through the x-ray machine with no problems.

Jim B.