Lens radioactivity

M-88 · Aug 10, 2018

Hello

I happened to acquire an old "G.Zuiko" 50 mm f/1.4 lens with a serial number 7xxxxx which doesn't have a silver nose, but has a yellow glass in front. I know from various sources (unfortunately they vary in information) that either all silver-nose 50 mm f/1.4 Zuiko lenses, OR all yellow-glass 50 mm f/1.4 Zuiko lenses are radioactive.

I have some old Soviet lenses with Lanthanum glass and I know they exhibit some radiation, but their front elements are miniscule compared to that of Zuiko. I also know that 50 mm f/1.4 isn't a huge improvement over f/1.8 and I wouldn't buy one if it was up to me in the first place, but right now this is where I am and here come the questions:

1. How radioactive are they?
2. Is my sample radioactive at all?
I have no Giger counter so I can't check.

Ces1um · Aug 10, 2018

M-88 said:
Hello

I happened to acquire an old "G.Zuiko" 50 mm f/1.4 lens with a serial number 7xxxxx which doesn't have a silver nose, but has a yellow glass in front. I know from various sources (unfortunately they vary in information) that either all silver-nose 50 mm f/1.4 Zuiko lenses, OR all yellow-glass 50 mm f/1.4 Zuiko lenses are radioactive.

I have some old Soviet lenses with Lanthanum glass and I know they exhibit some radiation, but their front elements are miniscule compared to that of Zuiko. I also know that 50 mm f/1.4 isn't a huge improvement over f/1.8 and I wouldn't buy one if it was up to me in the first place, but right now this is where I am and here come the questions:

1. How radioactive are they?
2. Is my sample radioactive at all?
I have no Giger counter so I can't check.

there are other posts here on photrio about radioactive lenses and the general concensus I believe is that they are perfectly safe. Just don't spend 24 hours a day with them in contact with your body. How big is this zuiko? Obviously the more radioactive material there is, the higher the dose. If this thing is the size of a pizza box maybe you need to worry.

AgX · Aug 10, 2018

I put a Geiger counter to my old Zuiko 50mm lens and the noise from the counter when put to the lens was very annoying....
(No yellow glass though.)

With my sample the radiation was strongest at the rear, if I remember right.

If you do not feel well with the idea of having a radiating lens, just don not get one, there are alternatives. But we had discussions with exact figures and evaluations.

Sirius Glass · Aug 10, 2018

This has been covered before in threads. Basically the amount of radioactivity in lenses is not enough to be concerned about even over long periods of time.

BMbikerider · Aug 10, 2018

I have a Minolta 28mm F2.8mc Rokkor which has a Thorium coating to one or more elements. It does give quite a strong yellow cast onto colour film so I use it for B&W only. The yellow cast has the same effect as approximately a 2x yellow filter. As said before, the quantity of radio activity emitted from a lens can be discounted, but Thorium in it's pure state has a half life quoted as 14.05 billion years, or half that of the estimated age of the universe!

Old as it is, the quality of the B&W images created by this lens are outstanding and possibly the sharpest lens I own in Minolta manual fitting. Corner to corner from F3.5 down to about F12.5 it is quite outstanding.

Having checked on the other rare earth element used in lenses, - lanthanum.... there is no indication from technical sources that this element is radio active.

Dali · Aug 10, 2018

M-88 said:
Hello

I happened to acquire an old "G.Zuiko" 50 mm f/1.4 lens with a serial number 7xxxxx which doesn't have a silver nose, but has a yellow glass in front. I know from various sources (unfortunately they vary in information) that either all silver-nose 50 mm f/1.4 Zuiko lenses, OR all yellow-glass 50 mm f/1.4 Zuiko lenses are radioactive.

I have some old Soviet lenses with Lanthanum glass and I know they exhibit some radiation, but their front elements are miniscule compared to that of Zuiko. I also know that 50 mm f/1.4 isn't a huge improvement over f/1.8 and I wouldn't buy one if it was up to me in the first place, but right now this is where I am and here come the questions:

1. How radioactive are they?
2. Is my sample radioactive at all?
I have no Giger counter so I can't check.

I would suspect that, due to history, Japaneses lens makers would be cautious with radioactivity...

M-88 · Aug 10, 2018

Ces1um said:
there are other posts here on photrio about radioactive lenses and the general concensus I believe is that they are perfectly safe. Just don't spend 24 hours a day with them in contact with your body. How big is this zuiko? Obviously the more radioactive material there is, the higher the dose. If this thing is the size of a pizza box maybe you need to worry.

The glass is probably around 40 mm or so, whereas soviet Industar is two times smaller. I'll buy a leaded lens cover

AgX said:
With my sample the radiation was strongest at the rear, if I remember right.

Strange. Because from what I've read elsewhere, they were more radioactive on the front instead of rear.

Sirius Glass said:
This has been covered before in threads. Basically the amount of radioactivity in lenses is not enough to be concerned about even over long periods of time.

I will make sure to use a search engine next time.

BMbikerider said:
I have a Minolta 28mm F2.8mc Rokkor which has a Thorium coating to one or more elements. It does give quite a strong yellow cast onto colour film so I use it for B&W only. The yellow cast has the same effect as approximately 2x yellow filter. As said before the quantity of radio activity emitted from a lens can be discounted, but Thorium in it's pure state has a half life in excess of 2 million years. Old as it is, the quality of the B&W images creatd by this lens are outstanding and possibly the sharpest lens I have in Minolta fitting. Corner to corner from F3.5 down to about F12.5

Interesting. By the way, I've read that yellow cast can be removed by leaving the lens in the sunlight, but I think it won't be too beneficial to other elements of the lens. So if I ever want to do it, I better disassemble the lens and put only the glass in the sunlight.

Dali said:
I would suspect that, due to history, Japaneses lens makers would be cautious with radioactivity...

Who knows. I trust Japanese radioactive glass more than Soviet radioactive glass anyway

Theo Sulphate · Aug 10, 2018

You are exposed to more radiation eating bananas, living in a brick house, or flying in an airplane.

Just don't eat the lens, nor sleep with it, nor break it so that glass shards are imbedded in your body.

AgX · Aug 10, 2018

The greatest risk was for the people manufacturing the glass resp. the lens elements.
(And is still for the people having the resulting slurry dump at their doorstep.)

But as with any risk it nevertheless is a matter of feeling at ease or not.

M-88 · Aug 10, 2018

Dear Sirs, duly noted!

P.S. Didn't know sleeping next to someone gave me radiation. I should divorce.

Sirius Glass · Aug 10, 2018

What is the technical name for a janitor in Chernobyl?

Mop and glow

Theo Sulphate · Aug 10, 2018

M-88 said:
...
P.S. Didn't know sleeping next to someone gave me radiation...

Only if they're hot.

guangong · Aug 10, 2018

My Lone Ranger Atomic Ring probably emitted more radioactivity than your lens, not to mention the mineral collection I used to have. Still here and healthy.

abruzzi · Aug 10, 2018

Theo Sulphate said:
, nor sleep with it,

At least not until after the third date.

Another little known radiation fact: the silk mantles for Coleman lanterns back in the day were impregnated with thorium and were radioactive. Coleman phased out Thorium around 1990, and gradually other manufacturers phased it out as well, but even into the 2000s thorium mantles we’re still made. Now they’re all Yttrium, and not as good.

Theo Sulphate · Aug 10, 2018

abruzzi said:
...
Another little known radiation fact: the silk mantles for Coleman lanterns back in the day were impregnated with thorium and were radioactive. Coleman phased out Thorium around 1990...

One guy knew about it: Google "radioactive Boy Scout" - an intelligent and resourceful young man who built a reactor in his garage. If I remember correctly, he detected excessive radiation from it in his neighborhood, so he had to call the authorities in to help get rid of it...

On a related matter: I replaced my Canon 35/2 FD lens which had thorium glass with a non-thorium Canon 35/2, the reason being that it was already yellowing and I did not want to cook it out in the hot sunlight.

RalphLambrecht · Aug 11, 2018

Sirius Glass said:
This has been covered before in threads. Basically the amount of radioactivity in lenses is not enough to be concerned about even over long periods of time.

just don't keep them in your pocket.

AgX · Aug 11, 2018

abruzzi said:
Another little known radiation fact: the silk mantles for Coleman lanterns back in the day were impregnated with thorium and were radioactive.

To my understanding ALL gas mantles since the late 19th century contained radiactive Thorium. Thus not only some camping lanterns, but all gas street lanterns too. Over here some are still existant with those radioactive mantles.

M-88 · Aug 11, 2018

guangong said:
My Lone Ranger Atomic Ring probably emitted more radioactivity than your lens, not to mention the mineral collection I used to have. Still here and healthy.

Lone Ranger atomic ring? That was around 70 years ago

removed account4 · Aug 11, 2018

you might consider wearing a devo jump suite whenever you use the lens
http://www.clubdevo.com/2015/09/13/devo-halloween-costumes/
energy domes would be helpful too..

guangong · Aug 11, 2018

M-88 said:
Lone Ranger atomic ring? That was around 70 years ago

At least! Worked on the same principle as the little screen mounted in an eyepiece that Several years later I used for identifying radioactive minerals. In the modern nanny state probably all would be illegal.

removed account4 · Aug 11, 2018

guangong said:
In the modern nanny state

not sure if i would call anything a modern day nanystate
there are plenty of dopes doing dopy things and killing themselves
the problem is they tanke down some innocents and al hell brakes lose.
like the guy who stole an jet airliner yesterday ... or may bee, i guess ... washington isn't a nanystate

pentaxuser · Aug 11, 2018

RalphLambrecht said:
just don't keep them in your pocket.

Would that advice apply to trouser pockets only

pentaxuser

Sirius Glass · Aug 11, 2018

RalphLambrecht said:
just don't keep them in your pocket.

The threads are listed below and the search works well. The OP needs to do some homework.

Theo Sulphate · Aug 11, 2018

jnanian said:
...
like the guy who stole an jet airliner yesterday ...

It was a Bombardier Q400 Turboprop - one of my favorite types of aircraft. He may have crashed one that I'd even flown on numerous times - I'll have to check the registration number when it's available.

M-88 · Aug 12, 2018

Sirius Glass said:
The threads are listed below and the search works well. The OP needs to do some homework.

Yes Sir, I've noticed that search system works surprisingly good (unlike other Google based embedded search encountered elsewhere). However either I'm missing some data, or there's not much in regards to non-silvernise "G. Zuiko" 50/1.4 specifically.

Lens radioactivity

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