Are Pentax lenses radioactive?

There are a significant number of lenses produced between 1940 and 1970 that are measurably radioactive, like the Pentax SMC Takumar 50mmf/1.4 lens Walker shows in the video above. Thorium Oxide is the main culprit of this radioactivity and was applied to glass elements because of its crystalline structure.

Why are some lenses radioactive?

Main source of radioactivity is the use of thorium oxide (up to 30\% by weight) as a component of the glass used in the lens elements. The presence of thorium can sometimes, depending on the mixture of other elements in the lens, cause moderate to severe browning of the lens elements.

What are radioactive lenses?

Radioactivity in old camera lenses is due mostly to the widespread use of thorium glass elements in the 1940s, ’50s, ’60s and ’70s. Thorium oxide is highly refractive and low dispersion; this translated into cheaper high-quality glass by allowing manufacturers to make lenses of lesser curvature.

Which Takumar lenses are radioactive?

Radioactive Pentax and Takumar lenses.

Lens	Serial	radioactive
SMC takumar 1:1.4/50	7780013	yes
super-takumar 1:2/35	1258114	yes
super-multi-coated takumar 1:4.5/20	5403707	yes
super-multi-coated takumar 1:3.5/28	8315160	no

Are radioactive lenses harmful?

In conclusion – no, you can’t get sick or die from radioactive lenses. You’d have to spend months in a room filled with 2 million of them in order to feel any consequences, and I believe no one’s collection is that big. So, if you have a couple of good ones, don’t be afraid to use them.

How can you tell if a lens is radioactive?

But first, how do you know if your lens contains Thorium? If you can see yellowish tint on the glass, this means your lens contains this element. Thorium was used to improve the image quality, but the downside is that it becomes yellowish with time. And, well, that it’s radioactive.

Why it is safe to use radioactive glass in the camera as shown?

The eye is very sensitive to Alpha and Beta particles and is easily susceptible to damage from even a small dose from a lens or a camera eyepiece made with radioactive glass. It is commonly believed that these lenses improve the color reproduction and reduce errors in their visual representation.

Are Helios lenses radioactive?

The Helios is not radioactive….Russian manufacturers usually copy quality lenses and manufacture them in mass quality.

Is Industar 61 radioactive?

Concluding: as you’ll sometimes read, the Industar-61L/D is indeed radioactive, but its radiation is already hard to make out against the background radiation, and comes nowhere near the levels you absorb when sunbathing or flying. So for all practical uses, the FED-5 with Industar-61L/D is perfectly safe.”

(Lanthanum is also frequently encountered in high-index glasses and is naturally radioactive, but far less so than thorium. Lanthanum decay radiation from lenses requires very sensitive equipmen I have never encountered a lens made by Pentax itself that is detectably radioactive.

What are radioactive lenses made of?

General Edit. There are a significant number of lenses produced from the 1940s through the 1970s that are measurably radioactive. Main source of radioactivity is the use of thorium oxide (up to 30\% by weight) as a component of the glass used in the lens elements. Thorium oxide has a crystalline structural similar to calcium fluoride ( fluorite ).

Who invented the first radioactive camera lens?

– United States Patent 2,466,392. Kodak produced some of the first radioactive lenses for aerial surveillance – the Aero-Ektar. Other manufacturers like Canon, Konica, Asahi Pentax, and others also used thorium in their lenses made between about 1945 and 1980.

Do Pentax lenses contain thoriated lenses?

However, a number of higher-quality lenses that were popular on Pentax cameras (and are sometimes encountered on them in flea markets), such as certain Asahi Takumars dating from the 1960s-70s, are radioactive due to thorium content. To my knowledge, no current or recently-produced lenses contain thoriated optics.