Takumar radioactivity and serial numbers

[MrCynical]

I'm aware of the radioactivity issue with some Takumars. The importance or otherwise of this has been discussed to death already, but I'm trying to work out if a particular lens (which I don't yet own) is affected by the issue. I understand that it's possible to tell this by the serial number of the lens (presumably serial number relates to production date?) However I've been unable to find the page containing such information - if anyone knows it (or knows the serial number range affected) could you please let me know?

[indianadinos]

Hi,

Welcome to the forum ...

AFAIK, all the old Takumars use radioactive elements (thorium ? lanthanum ?) to reach high IQ (as, amongst other things, some "modern" manufacturer still do - guess the origin of the APO-Lanthar name), so the serial number wouldn't be of great help ...

Personally, i don't care about this, i have some (too many, according to my friend ) Takumars, and, despite their radioactive elements, i still don't have a greenish skin and peaky ears


Cheers

[MrCynical]

Hmm, thanks. Looks like it's back to searching for the better-OEM Vivitars for me

[no-X]

I think the only problem is that we know about the radioactivity. I believe many other lenses use radioactive elements, but nobody did a measurement, so we don't know about it.

[CarbonR]

Thoriated Takumars are :
- Super Takumar 35/2 (V2, 49mm filter)
- S-M-C Takumar 35/2
- Super Takumar 50/1.4 (V2, 7 elements, oval lettering, SN greater than 1400000 according to taunusreiter.de, infrared mark at the opposite side of the focus mark)
- S-M-C Takumar 50/1.4
- All the 55/1.8 and f/2 (not sure, if someone can confirm that, but my 55/1.8 are yellowish)
- Super and S-M-C Takumar/6X7 105/2.4

I sleep with all my radioactive lenses in my room

[Rolf]

If you own a clock from Switzerland - please remove this.

Few days ago was a report in a German newspaper that the illuminant on the watch hands contains radioactive ingredients by many of these clocks.

Could be dangerous if the glass of your clock is broken and the "small glass" on the watch hands (where this illuminant is in) too.

You see, life is full of risks.

[no-X]

I read somewhere, that many old items can be radioactive, because they were made of materials, which weren't known for radioactivity. Quite common can be old ceramics (e.g. tiles or some crockery) and old pigments (used for bijouterie/jewels or colored wall tiles).

http://hps.org/publicinformation/ate/cat40.html#186
http://www.msnbc.msn.com/id/3077213/

[visualopsins]

Those glowing "EXIT" signs in widespread global use all contain radioactive Tritium and everybody on Earth has been exposed to Plutonium fallout from that exploded satellite years ago...

Imho the danger from broken fluorescent bulb mercury is far greater. Not to mention water and food supply contaminants, and those poor folks on the East coast of Africa glowing from illegal offshore dumped spent nuclear fuels.

Comparatively speaking, radioactive lens elements are nothing...

Still, I would like to take radioactive lens self portraits. Film fogging takes too long, so now I'm thinking something along lines of Spinthariscope, which I had as child, perhaps using a filter coated with scintillating material such as Calcium Fluoride between hot lens and taking lens...the radiation patterns might be quite beautiful, like snowflakes...[/quote]

[indianadinos]

Hi,

[kds315*]

Oh well, another one of these threads, same questions, same answers.....
same "usual suspects".

I seriously hope no-one of the "now all shivering in fear" ate mushrooms for the last ten years after Tschernobyl since these were highly contaminated with radioactive Cerium just to add another "threat"...

Anyway, life IS dangerous and I'm not saying that we shouldn't be careful, but to access risks the way they are, smaller and bigger and to act accordingly.

[peterqd]

This gets really tedious. Has anyone ever heard of anybody actually being affected by using thoriated Takumar lenses? If so, there would have been a major news story in the photo world and the lenses would have been banned long before now.

Please could someone confirm - wouldn't film in the camera, so close to the lens, become fogged by the radiation long before there was any damage to the cameraman?

I'm pretty certain the 1.8/55 and 2/55 lenses never had any thoriated glass. I have three versions and they're all crystal clear.

[no-X]

peterqd: Not all thoriated/radioactive lenses turn yellow or brown. If the thorium is clean enough (or the lens use modern optical glue), the glass colour can stay unchanged. E.g. Yashinon DS-M 50/1.4.

[peterqd]

[estudleon]

Oh, I will turn to green head. I own a clock from Switzerland, a SMC 1,4/50, a Pancolar 1,8/50 and I like the three a lot!!!

The Kodak aerial is the lens with more radiactive elements, isn't it?

An old seller (pentax fan) told me that the better way to have a clean thoriated lens is putting it under UV light for a month or so once a year. I did it with my SMC 1,4/50 in dicember '09. Let we see across the '10.

The number of production in Pentax isn't very reliable. My S-M-C has a number of serie later than a SMC and the first was made before than the second.

Rino.

[CarbonR]

[indianadinos]

[peterqd]