[iNicole]

Hi,

So I'm planning to buy a radioactive lens. I know it sounds crazy.. but it's a fantastic lens in great condition, it's just radioactive. The last thing I want is for my family to be harmed from the radiation of the lens. Do you think lead foil will be enough to protect from radiation? Or do I need something thicker?

Thanks,
Nicole

[simbon4o]

I don't think that it is dangerous . Most of the sources says that it is less radioactive then average mobile phone. So it must not be a huge problem.

[elliott]

Less than 1 inch of air is more than enough to "protect" from the super low radiation given off by thoriated lenses. Now protecting yourself from the many other more powerful radiation sources that you likely encounter on a daily basis is more difficult.

If these lenses gave off any significant radiation they would have fogged the film in the cameras.

[Frogfish]

I assume you are talking about some of the USSR lenses ? As far as I'm aware there was never any danger from them - just over-reaction from the West. However to be on the safe side wear a tin-foil helmet when using the lens

[mikeSF]

dont worry and have fun with it!

[elliott]

I assume you are talking about some of the USSR lenses ? As far as I'm aware there was never any danger from them - just over-reaction from the West. However to be on the safe side wear a tin-foil helmet when using the lens

Soviet lenses are not radioactive, it is most common in Japanese and German glass, thoriated glass was far too expensive and complex for the Soviets.

[Deimos]

avoid grinding up the rear element and serving it with dinner and you should be fine

[iNicole]

Soviet lenses are not radioactive, it is most common in Japanese and German glass, thoriated glass was far too expensive and complex for the Soviets.

Yes I am talking about japanese lenses, I heard that they were quite expensive to make and each copy made the company loose money.

Less than 1 inch of air is more than enough to "protect" from the super low radiation given off by thoriated lenses. Now protecting yourself from the many other more powerful radiation sources that you likely encounter on a daily basis is more difficult.

Okay, so you think that they won't be harmful at all? Or should I still protect myself from the lens when I'm not using it?

[Frogfish]

Soviet lenses are not radioactive, it is most common in Japanese and German glass, thoriated glass was far too expensive and complex for the Soviets.

Oops my mistake - I thought the Industar lenses were supposed to have minute quantities of radioactive material. Now if you are buying any Russian lenses on EBay that may have came from Chernobyl ......

[iNicole]

how much radiation does this lens "let out" compared to a fire alarm or mobile phone? If it's less, then I will buy it. I don't know if I would buy the lens if it let out more radiation as I will be putting the lens pretty close to my face..

[boriscleto]

Yes I am talking about japanese lenses, I heard that they were quite expensive to make and each copy made the company loose money.

As ahi introduced the Thoriated Super Takumar 50/1.4 (7-element) because it was less expensive than the non-Thoriated Super Takumar 50/1.4 (8-element).

Thorium dioxide was formerly added to glasses during manufacture to increase their refractive index, producing thoriated glass with up to 40% ThO2 content. These glasses were used in the construction of high-quality photographic lenses. However, the radioactivity of the thorium caused both a safety and pollution hazard and self-degradation of the glass (turning it yellow or brown over time). Lanthanum oxide has replaced thorium dioxide in almost all modern high-index glasses

Thoriated Camera Lens (ca. 1970s)

[vonBaloney]

Sounds like you are talking about some of the old Takumars. You don't have to worry about protecting yourself from it. You may have to give the glass a UV treatment to get rid of yellowing though...

[iNicole]

As ahi introduced the Thoriated Super Takumar 50/1.4 (7-element) because it was less expensive than the non-Thoriated Super Takumar 50/1.4 (8-element).

the 8-element version is not radioactive?

[boriscleto]

the 8-element version is not radioactive?

That is correct. The 8-element was only produced in 1965 and was not radioactive.

[elliott]

Oops my mistake - I thought the Industar lenses were supposed to have minute quantities of radioactive material. Now if you are buying any Russian lenses on EBay that may have came from Chernobyl ......

I think there is one Industar that uses lanthanum instead of thorium, but it is very uncommon to find, unlike the ubiquitous Super Takumar 50mm f1.4.

Okay, so you think that they won't be harmful at all? Or should I still protect myself from the lens when I'm not using it?

I've never treated my Super Takumar any different from my other lenses, other than using UV light to clear up the yellowing caused by the decay of the thorium. It is such a low dose of radiation that it would take a very, very long time to add up to anything that could do any measurable damage to the human body, I'm talking about 24/7 direct exposure for years.

It is pointless to compare it to a mobile phone because it is a totally different thing, a mobile phone emits radio waves, not alpha, beta or gamma rays, it is not ionizing radiation. A smoke alarm is probably more dangerous if kept at a similar distance, but you're never really that close to one for any extended period of time.