Radioactive lenses.

[waynecrider]

This is a camerapedia article on radioactive lenses. I don't know how truthful it is, but there was alot of Kodak lenses that supposedly were.

http://camerapedia.wikia.com/wiki/Radioactive_lenses

 

[Tom1956]

Pentax Takumars were, for sure. But you won't die from it.

 

[clayne]

Thorium dioxide was used to help increase the refractive index of elements (usually 1) in older designs before newer designs and glass formulations came about. It won't harm you and any yellowing of surrounding elements (this is ionization) is easily reversed with a black light on the lens for 7-30 days (depending on where the thoriated element is [usually in the rear group]).

Some older Nikkors were radioactive (my coveted 35/1.4 for instance), older 58mm Rokkors (58/1.2), Takumars, and the Kodak Aero-Ektars. Plenty of others too.

Many older designs utilizing radioactive elements are also, when designed well, kick ass lenses. Nothing to do with the thorium though.

 

[AgX]

The bigger problem is at the production side/site.
Kodak now has such a problem.

 

[IloveTLRs]

... It won't harm you and any yellowing of surrounding elements (this is ionization) is easily reversed with a black light on the lens for 7-30 days (depending on where the thoriated element is [usually in the rear group]). ...

The yellow in my 55/1.8 made a great yellow filter for B&W

 

[Mark Layne]

There is more radiation in most basements
Mark

 

[MartinCrabtree]

If it doesn't fog the film I'd imagine you're going to be OK.

 

[Dan Fromm]

Typical WIKI. Incomplete, some assertions possibly (probably?) false.

Re incomplete, I've had a small pile of radioactive lenses that showed radiation damage (yellowing) that I cleared by setting them lenses to bask under a UV-B bulb. None mentioned in the WIKI. Three TTH tessar type process lenses, One Schneider Repro-Claron.

Re possibly false, I have two 101/4.5 Ektars, one made in 1946. I haven't treated them with UV-B for radiation damage 'cos they show none. I wonder about (a) "Lenses Tested Radioactive (by the author)" and (b) Camerapedia's adherence to Wikipedia's rules. It could be that despite its name Camerapedia doesn't fall under the Wikipedia umbrella.

Re Wikipedia's rules, as I understand 'em Wikipedia allows nothing that hasn't been posted on the 'web. "I measured it" isn't allowed, neither is citing anything published on paper and not available on the 'web. Stupid, IMO.

Re Camerapedia in general, I'm somewhat of a specialist on a few topics -- I'm coauthor of the definitive, so far, account of Boyer lenses -- and was so offended by the garbled hash about Boyer lenses an illiterate fool put up on Camerapedia that I signed up and rewrote the mess. IMO Camerapedia is pretty worthless, mainly gets in the way. WIKI of the idiots, by the idiots, for the idiots.

 

[Gerald C Koch]

There are many radioactive sources which people contact every day. Some examples are granite counter tops, Coleman gas mantles and the famous black sand beaches in Hawaii.

Just don't sleep with the lens under your pillow.

 

[waynecrider]

Personally I'd say screw the radiation. Isn't it more the fact that the lenses were purported to be better with the thorium oxide which is why they used it in the first place.

 

[KennyMark]

(there was a url link here which no longer exists)

 

[Poisson Du Jour]

Put things in perspective: how much radiation will you get when you have an x-ray? Or an MRI? Or a CT scan? In all probability, the average house has much, much more radiation in it from appliances. All of those are infinitely more powerful than occasional exposure to a thorium-tainted lens. No big deal. Old Pentax Takumars had it. Whatever it was purported to do has long since faded into history, but such lenses are sought out by collectors for their curio value, if not actually used for photography. Speaking of which, it's probably time to get more lens work done than worrying about radioactivity.

 

[Dr Croubie]

Put things in perspective: how much radiation will you get when you have an x-ray? Or an MRI? Or a CT scan? In all probability, the average house has much, much more radiation in it from appliances.

http://xkcd.com/radiation/

I don't see Takumar on that list, but holding one up to your eye for 30 seconds (per frame) is probably about the same as eating a banana, (ie, SFA).

 

[markaudacity]

Re Wikipedia's rules, as I understand 'em Wikipedia allows nothing that hasn't been posted on the 'web. "I measured it" isn't allowed, neither is citing anything published on paper and not available on the 'web.

Wrong, wrong, wrong. The vast majority of Wikipedia sources cited are paper originals--books, newspapers, and professional/technical/trade journals. Wikipedia does not allow ORIGINAL research as a source, ie, that which has not been submitted to peer review.

 

[Sirius Glass]

There is more radiation in most basements
Mark

And from counter tops. You are in much greater danger from being run over by the proverbial bus.

 

[clayne]

Just don't take shots of granite counter tops with radioactive lenses. The optics will quadruple the radiation!