Wear your lead vest when using these lenses

[Mainecoonmaniac]

On some of these lenses, most of the radiation comes from the rear elements. Are these radioactive lens that much sharper?

https://www.youtube.com/user/uyt384

 

[LarryP]

they tend to be damn nice. I wouldn't worry about radiation from any lens that doesn't fog the film Just sayin'.

 

[PentaxBronica]

It occurs to me that you can make any measuring device appear to indicate a high reading by simply changing the units it measures in. I can't see what his geiger counter is measuring in, but the racket it makes suggests that he's switched it to be hyper-sensitive for an impressive result. If they were really as dangerous as the sizzling noise suggests then there would be camera collectors dropping dead from radiation poisoning all over the place!

 

[E. von Hoegh]

Has anyone bothered to find out just what paticles these lenses emit? You may wish to....
And as PentaxBronica said, you can make a meter say anything.
Lastly, it's on utoob ffs. Check out the bigfoot and ufo videos.

 

[PentaxBronica]

The fact that there's a much lower reading (regardless of sensitivity setting/units) when he puts the sensor against the front of the lens (and around the back until he presses it against the lens) would suggest that they're pretty weak particles. I'd expect the mirror, pressure plate, and back door of an SLR to block them pretty effectively.

Remember, a lot of substances aren't dangerous due to radioactivity. It's because they're a toxic metal like lead. Ingest them and you'll suffer from heavy metal poisoning rather than radiation sickness.

 

[Gerald C Koch]

The two most common radioactive metals used in making certain optical glasses are thorium and lanthanum. Unless you are going to sleep with one of these lenses under your pillow for months you are not at any risk. The refractive index of such glasses permit designers to make lenses with fewer elements or increased speed and contrast.

 

[Mainecoonmaniac]

The refractive index of such glasses permit designers to make lenses with fewer elements or increased speed and contrast.

Thanks for the information. Are there other glass additives that do the same without the radiation? :confused:

 

[benjiboy]

One of my son's is a nuclear physicist who works at a World renowned nuclear facility here in the U.K, I have a Canon FD mm f2 Thorium lens and asked him to research if it was safe, he told me the level of radiation it emits is very small and a fraction of that that workers in the nuclear industry are allowed to absorb annually, he also said that it wasn't much more than that emitted by bananas, or Brazil nuts, however he did say he didn't recommend that I sleep with it under my pillow.

 

[Christiaan Phleger]

Yes there are many glass additives that do the same, or close enough. In the early-mid 1970's the use of Thorium was phased out due to worker health, the dust from the grinding and polishing if inhaled was very bad. Later, the use of lead was cut down or eliminated (as widely touted by Canon).

 

[BrianShaw]

How would we see through the vest? I'd be more worried about getting that eye cancer that travels immediately to the brain.

 

[Mainecoonmaniac]

It's not my eyes that I'm concerned about

How would we see through the vest? I'd be more worried about getting that eye cancer that travels immediately to the brain.

Gotta shield the Family jewels

 

[benjiboy]

How would we see through the vest? I'd be more worried about getting that eye cancer that travels immediately to the brain.

It is illegal to put radioactive glass in eyepieces of optical instruments.

 

[BrianShaw]

I'm not currently breeding... so eyesight is more important.

 

[benjiboy]

Gotta shield the Family jewels

Wanna buy some lead lined boxer shorts

 

[benjiboy]

My son works in the nuclear industry and he tells me the dosage of radiation allowed for workers is rated in bananas
http://en.wikipedia.org/wiki/Banana_equivalent_dose, and that many items in the home like Brazil nuts, marble kitchen unit counter tops, and green Vitrolite bathroom tiles are radioactive but not to a level to cause concern.

 

[budrichard]

On some of these lenses, most of the radiation comes from the rear elements. Are these radioactive lens that much sharper?

https://www.youtube.com/user/uyt384

I little knowledge can be a dangerous thing.
Background, I have BS and MS degrees in Nuclear Engineering as well as having worked and managed all areas of Commercial Nuclear Power including Health Physics.
The device shown, Inspector EXP has a limit of 300,000 Counts per Minute(CPM) or 100mr/Hr.
Now one would not want to live in a 100mr/Hr radiation field but it would take over 4500 hours of continuous whole body exposure at 100 mr/Hr to reach the LD/50 or Lethal dose to 50% of the individuals exposed without any medical intervention.
The video seems impressive but the levels measured don't appear to excede 10,000 CPM or further factor of 300 less exposure. So a little noise makes what is in reality very low readings seem very impressive.
But there is more, the different organs of the body have different sensitivities to radiation, the lens of the eye being particularly more sensitive. Any beta(electrons) or Alpha(Helium nuclei) particles will be stoped by the body of the camera from reaching the eye leaving us to contend with Gamma(High energy Photons or light) particles.
At the levels this device appears to be measuring and the usage factor, I would not have any worries.-Dick

 

[Gerald C Koch]

When I was in grad school I worked in a lab and used a radiation counter. The detector assembly was enclosed in 2 inches of lead. One day a friend came in with his cup of coffee and set the cup down beside the counter. The cup was a cheap knockoff of Fiestaware made in Mexico and was orange in color. The counter went wild. Seems the cup had a uranium glaze and the manufacturer did not use depleted uranium. He stopped using the cup.

 

[BrianShaw]

Even the real Fiesta (orange) was radioactive, not just cheap knockoffs.

 

[Gerald C Koch]

he also said that it wasn't much more than that emitted by bananas, or Brrazil nuts,

Both bananas and Brazil nuts are high in potassium. 40K is radioactive decaying mostly by emission of a beta particle. Fortunately for us it has a very long half-life of 1.2×109 years. Still each of us experiences about 4500 events/s from the potassium in the body.

 

[michaelbsc]

...Seems the cup had a uranium glaze and the manufacturer did not use depleted uranium. He stopped using the cup.

Depleted uranium wouldn't help much. The uranium part of depleted uranium is still uranium, and the depleted part isn't uranium any more.

What they were using was that wonderful yellow powder called yellow cake as a base for the color. Obviously something red added to get orange.

 

[BrianShaw]

http://en.wikipedia.org/wiki/Fiesta_(dinnerware)#Radioactive_Glazes

 

[Klainmeister]

I little knowledge can be a dangerous thing.
Background, I have BS and MS degrees in Nuclear Engineering as well as having worked and managed all areas of Commercial Nuclear Power including Health Physics.
The device shown, Inspector EXP has a limit of 300,000 Counts per Minute(CPM) or 100mr/Hr.
Now one would not want to live in a 100mr/Hr radiation field but it would take over 4500 hours of continuous whole body exposure at 100 mr/Hr to reach the LD/50 or Lethal dose to 50% of the individuals exposed without any medical intervention.
The video seems impressive but the levels measured don't appear to excede 10,000 CPM or further factor of 300 less exposure. So a little noise makes what is in reality very low readings seem very impressive.
But there is more, the different organs of the body have different sensitivities to radiation, the lens of the eye being particularly more sensitive. Any beta(electrons) or Alpha(Helium nuclei) particles will be stoped by the body of the camera from reaching the eye leaving us to contend with Gamma(High energy Photons or light) particles.
At the levels this device appears to be measuring and the usage factor, I would not have any worries.-Dick

Hey Dick, you still work in the nuclear industry? Where ya at?

 

[E. von Hoegh]

How would we see through the vest? I'd be more worried about getting that eye cancer that travels immediately to the brain.

You get that from TV, not camera gear. Camera gear is actually an antidote.

 

[DREW WILEY]

Lens design in the EU or for anything marketing to the EU has had to change due to ingredient
restrictions, including radioactive or toxic. Some excellent lenses have disappeared from new mfg
due to this. The classic dye transfer color prining process used a Thorium mordant. Some of us have
substituted uranyl nitrate (lab grade yellowcake). Can cause a customs issue in certain cases, but 100g per purchase is really silly to question, because it would take shiploads of the stuff to make
a dirty bomb.

 

[benjiboy]

What about Thorium toothpaste http://www.orau.org/ptp/collection/quackcures/toothpaste.htm, the mind boggles.