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12 minutes ago, 28framelines said:

I believe my question says it all. I just can’t find anywhere on the internet that says whether or not it was made with radioactive materials for lens coatings because I’d like to avoid it if possible.

i thought only the collapsible summicron 50mm had radioactive elements

even then, unless you hold it upto your eye for a while its not going to affect you

https://www.youtube.com/user/uyt384/videos

 

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11 minutes ago, earleygallery said:

Why avoid it? It's not going to pose any risk to you.

Because my family is prone to cancer maybe? 
 

2 minutes ago, spydrxx said:

Run it by a geiger counter if you're so worried.

I cannot, as I’d be buying one off eBay most likely. If I could do that, why would I be asking here? Lol.

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2 minutes ago, 28framelines said:

Because my family is prone to cancer maybe? 
 

I cannot, as I’d be buying one off eBay most likely. If I could do that, why would I be asking here? Lol.

If you're in the USA your local fire dep't or police station probably has a geiger counter because of hazardous waste  spills and fires - FWIW. If you have an old wristwatch, its lume would have higher radiation levels than most radioactive lenses. You could try contacting Leica in Wetzlar with the serial number as well, their records might be useful in answering your question.

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12 minutes ago, spydrxx said:

If you're in the USA your local fire dep't or police station probably has a geiger counter because of hazardous waste  spills and fires - FWIW. If you have an old wristwatch, its lume would have higher radiation levels than most radioactive lenses. You could try contacting Leica in Wetzlar with the serial number as well, their records might be useful in answering your question.

Thank you! That is very helpful!

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1 hour ago, 28framelines said:

I believe my question says it all. I just can’t find anywhere on the internet that says whether or not it was made with radioactive materials for lens coatings because I’d like to avoid it if possible.

You could always avoid any theoretical risk - real or imagined - by simply not buying one. Seriously; how many alternative 35mm lens options are out there?

Philip.

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6 hours ago, 28framelines said:

I believe my question says it all. I just can’t find anywhere on the internet that says whether or not it was made with radioactive materials for lens coatings because I’d like to avoid it if possible.

No Leica M lenses have radioactive "coatings."

One Leica M lens used radioactive thorium oxide in the glass itself (not a coating) - the original 50 Summicron (the 1953 collapsible design). The heavy metal oxide in the glass improved the light-bending ability. Today, those lenses put out about 1.14 to 1.5 microsieverts/hour of alpha/beta radiation, as detected at the front/back surface of the lens unit.

https://petapixel.com/2018/06/07/a-radioactive-lens/

For comparison, in a year, the average human is exposed to around 2400 microsieverts from the natural world. To get that exposure from a 50mm Summicron Collapsible would require picking up the lens by the mounting flange (worst case - close encounter with the back end of the lens) about 1600 times per year. Or putting one's hand very close to the front of the lens (e.g. change a filter or remove/replace the lens cap) about 2260 times a year.

That's in addition to the expected natural background exposure, thus doubling it. Not absolutely negligible, but it depends on how often one does those things. And a cloth glove about the thickness of the M shutter curtains is enough to block the radiation.

In any case, Leica replaced the thorium glass with lanthanum glasses in the next design of the 50mm Summicron (1956 - the non-collapsible "Rigid" or "Dual Range" lenses).

Thorium glass use in consumer photographic lenses was phased out around 1970 (just before the creation of the 35 Summicron v.3 in 1971). Because it was found the radioactivity degraded the glass itself over time (yellowing).

Edited by adan
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51 minutes ago, adan said:

No Leica M lenses have radioactive "coatings."

One Leica M lens used radioactive thorium oxide in the glass itself (not a coating) - the original 50 Summicron (the 1953 collapsible design). The heavy metal oxide in the glass improved the light-bending ability. Today, those lenses put out about 1.14 to 1.5 microsieverts/hour of alpha/beta radiation, as detected at the front/back surface of the lens unit.

https://petapixel.com/2018/06/07/a-radioactive-lens/

For comparison, in a year, the average human is exposed to around 2400 microsieverts from the natural world. To get that exposure from a 50mm Summicron Collapsible would require picking up the lens by the mounting flange (worst case - close encounter with the back end of the lens) about 1600 times per year. Or putting one's hand very close to the front of the lens (e.g. change a filter or remove/replace the lens cap) about 2260 times a year.

That's in addition to the expected natural background exposure, thus doubling it. Not absolutely negligible, but it depends on how often one does those things. And a cloth glove about the thickness of the M shutter curtains is enough to block the radiation.

In any case, Leica replaced the thorium glass with lanthanum glasses in the next design of the 50mm Summicron (1956 - the non-collapsible "Rigid" or "Dual Range" lenses).

Thorium glass use in consumer photographic lenses was phased out around 1970 (just before the creation of the 35 Summicron v.3 in 1971). Because it was found the radioactivity degraded the glass itself over time (yellowing).

Thank you for the detailed explanation!

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3 hours ago, Danner said:

The Leica "glow", is it radioactive?  Inquiring minds want to know...

The 'glow' refers to a rendering quality of the lens, not what happens to the photographer using it 😉

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4 minutes ago, logan2z said:

The 'glow' refers to a rendering quality of the lens, not what happens to the photographer using it 😉

My daughter "glows" when somebody compliments her photographs....just sayin😄

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