Radioactivity in lanthanum containing lenses is due to the intentional inclusion of thorium in the optical glass mix. 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.
In the same way When did they stop using thorium in camera lenses?
The production of such lenses seems to have ended in the late 1980s. Camera lenses known to have contained thorium include: Canon FL 58mm f1.
Subsequently, Are FD lenses radioactive? Radioactivity. Like a number of other contemporary lenses, the Canon FD 55mm ƒ/1.2 AL incorporated thoriated glass, a kind of optical glass that is doped with thorium dioxide. The inclusion of this compound makes the glass radioactive.
Is it safe to use radioactive glass in a camera?
Most commonly the dose of radiation from using a radioactive lens approaches that of having an x ray at 10 mR/hr. … 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.
Do old cameras have radiation?
Radioactivity in old camera lenses is due mostly to the widespread use of thorium glass elements in the 1940s, ’50s, ’60s and ’70s. … The real threat comes from thorium eye pieces, which are much more rare but would be very close to a very sensitive area.
Are old camera lenses radioactive?
If you use vintage lenses, you might have heard that some of them are radioactive. As a matter of fact, many lenses produced between the 1940s and the 1970s emit a measurable amount of radioactivity. It comes from the element named Thorium, which was used in the glass elements of the lenses.
What is thorium dioxide used for?
Thorium Dioxide is a heavy, white, crystalline (sand-like) powder. It is used in ceramics, in nuclear fuels, as a catalyst, and in electrodes for arc welding.
How do you store radioactive lenses?
Ambient reading from Geiger Counter averaged around 15 CPM. So storing a radioactive lens in glass seems the best budget solution for shielding. Best defense is distance, so the further away the more scattered the radiation becomes.
Which Leica lenses are radioactive?
For the record, thorium (aka Torio) glass was used for elements 1, 3, 6, and 7. These lenses are the unique and collectible “radioactive Summicrons” of lore and legend that tend to acquire a yellowish-brownish cast over time that can be eliminated by extended exposure to UV (that is, sunlight.)
Are vintage lenses radioactive?
Some lenses produced from the 1940s through the 1970s were treated with radioactive thorium oxide to curb chromatic aberration. … 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.
Is Helios 44 radioactive?
This lens is not radioactive.
Why is it safe to use radioactive glass in a camera?
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.
What is the half life of thorium?
The time required for a radioactive substance to lose 50 percent of its radioactivity by decay is known as the half-life. The half-life of thorium- 232 is very long at about 14 billion years.
What are the dangers of thorium?
Thorium is radioactive and can be stored in bones. Because of these facts it has the ability to cause bone cancer many years after the exposure has taken place. Breathing in massive amounts of thorium may be lethal. People will often die of metal poisoning when massive exposure take place.
What happens if you touch thorium?
And there is research evidence that inhaling thorium dust increases the risk of lung and pancreatic cancer. Individuals exposed to thorium also have an increased risk of bone cancer because thorium may be stored in bone.
What is the 90th element?
Today, its radioactivity seems logical as when we look at the periodic table, we find thorium, element 90, just after actinium in the last row of the periodic table known as the actinides, comprising of famous radioactive elements such as uranium and plutonium.
How was uranium glass made?
Uranium glass is glass which has had uranium, usually in oxide diuranate form, added to a glass mix before melting for colouration. The proportion usually varies from trace levels to about two percent uranium by weight, although some 20th-century pieces were made with up to 25 percent uranium.
Are Helios lenses good?
Legendary Helios lens. This focal lenght is great for shooting portraits. In the pictures draws a remarkable blur of areas of sharpness (side). Enough for shooting in moderate lighting conditions.
Is Industar 61 radioactive?
It weighs only 129 grams. “L / D” in the name of the lens indicates that the glasses were impregnated with the rare earth Lanthanum. Lanthanum is actually slightly radioactive. However, the radiation is less than the background radiation we are exposed on earth anyway.
What is a Helios lens?
Helios (Russian: Ге́лиос) was a brand of camera lenses, made in the USSR. They were usually supplied with Zenit cameras and thus usable with other M42 lens mount cameras such as the Pentax Spotmatic. … The Helios-44 and Helios-40 are derivatives of the Carl Zeiss Biotar optical formula.
Are Helios lenses radioactive?
This lens is not radioactive.
Why did they name thorium after Thor?
In 1815, for example, Berzelius isolated a new element from a mineral sent to him from the Swedish mining town of Falun and named it thorium after the Scandinavian god of thunder, Thor.
Can thorium be weaponized?
Although some wonder if thorium can be used in nuclear weapons and are concerned about the possibility of a thorium bomb, thorium actually can’t be weaponized because it doesn‘t produce enough recoverable plutonium, which is required for building nuclear weapons.
What does thorium do to the human body?
Studies of thorium workers have shown that breathing thorium dust may cause an increased chance of developing lung disease and cancer of the lung or pancreas many years after being exposed. Changes in the genetic material of body cells have also been shown to occur in workers who breathed thorium dust.
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