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Radioactive lenses
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PostPosted: Thu Sep 29, 2011 12:18 pm    Post subject: Reply with quote
Radiation not harm on same way every people it can be very different, some people has trouble from smaller amount some people don't have any trouble from HUGE, really huge one.


PostPosted: Thu Sep 29, 2011 3:16 pm    Post subject: Reply with quote
funny enough, today I´ve read an article:

http://translate.google.com/translate?sl=cs&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fzpravy.idnes.cz%2Fhodinky-na-hristi-zapipaly-a-fyzik-amater-bezel-kvuli-radiaci-pro-pristroje-17i-%2Fdomaci.aspx%3Fc%3DA110929_122948_domaci_jj

briefly - an amateur scientist found radium emiter on children´s playground when playing with his son and wife Laughing it was there for at least 50years and no one has even noticed. that demonstrates how lens radioactivity (which is far more lower) might be dangerous Laughing


PostPosted: Thu Sep 29, 2011 4:02 pm    Post subject: Reply with quote
I don't know as much about radiation as I should, but common sense is a very valuable thing.

1 If the radiation emitted from a lens was at all harmful, surely no manufacturer would have released it and any government would have banned it long ago.

2 If the radiation emitted from a lens was at a harmful level, surely it would quickly fog any film in the camera.

3 The sensitivity of geiger counters is not necessarily related to danger to life. Like voltmeters, they can measure infinitesimally small levels at certain settings. Just because the reading looks high and the thing is beeping like mad, it doesn't mean there is any danger. In the wrong hands they can cause misguided anxiety.

4 The radiation from thoriated glass consists of alpha particles with accompanying gamma radiation. Alpha particles have a range of only a few centimetres in air and are absorbed even by tissue paper, let alone camera bodies. Even within range, they cannot penetrate human skin more than a few cells deep. The only danger from alpha particles is if the source is ingested.

http://www.epa.gov/radiation/radionuclides/thorium.html#affecthealth
(Useful reading)


PostPosted: Thu Sep 29, 2011 9:23 pm    Post subject: Reply with quote
peterqd wrote:
pdesopo wrote:
This is a very interesting thread.
So, no freedom to don't believe in science?

You question whether science is truth? Shocked Good or bad, if it wasn't for science we wouldn't know anything about radiation at all.


My question isn't that shocking peterqd. Science isn't truth neither exact. Einstein theories, believed as one of the most incredible lately quest, now are being put under a different light after the latest test at CERN.
For years nobody questioned about the use of mobile phones, lately this changed. Science believed that atom was the smallest thing, Hertz was positive about the impossibility of long distance communication, and so on.

Science is not the truth or a dogma, otherwise it wouldn't make any sense keep researching. In fact, science sets its own success after its mistakes, as that's the only way to prove and discover if something may work or not.

The thing is not what I or you believe. Said that, luckily we're free to believe what we like. So, it's completely fine if you or the rest of the world believe that science is the truth or that is perfect. I have the right to believe that is not.

Yes, without science we wouldn't be aware of the existence of the radiations. What does this prove? nothing, as science never states that since something has been discovered then suddenly we know everything about that. Discovering something is not knowing it.

But then again, I think the most important thing to bear in mind is what Attila said:

attila wrote:
I think that will be unpolite I really don't want to hurt those people who beleive it this is a real problem. They have same right to beleive in it, than I have to don't .


So, we can keep talking about what's true or not for the rest of our entire lives, as obviously this is the kind of matter that hardly will see two persons with different ideas ending up agreeing. And that's fine, as like I said, that's the nice thing here, be free to believe what one prefers to believe in.

Since this is a respectable forum I can see that what you would like to avoid here is false statements. I think that it would be either way a respectable forum giving, as you're already doing, just the theory behind the matters. Then it's up to the reader makes his/her own conclusion.

Like that nice statement says:
Quote:
I disapprove of what you say, but I will defend to the death your right to say it


PostPosted: Thu Sep 29, 2011 9:44 pm    Post subject: Reply with quote
I think it's a cool party trick. "Can your lense do this?" Laughing


PostPosted: Thu Sep 29, 2011 10:18 pm    Post subject: Reply with quote
Pietro, I respect everything you say. You've made some important points.

I think maybe there is a little language problem. When you say "I don't believe in xxxx" it means you don't believe xxxx actually exists. The word "in" changes the meaning, e.g. "I don't believe IN Santa Claus" has a completely different meaning to "I don't believe Santa Claus". I think you probably mean you don't believe everything science tells you, and there I think you have a strong case.

Of course science doesn't have every answer, but the answers it has so far are all the truth, to the extent of the scientists' knowledge. That is, scientific facts are not deliberate lies. But equally it's not like a religion you believe or not, with no proven facts at all.

I've given the facts about radiation from thoriated lenses as far as I know them, but I'm sure we have members who know a lot more than me. You are an intelligent person, able to research the facts and make up your own mind, and you are perfectly entitled to your beliefs.


PostPosted: Thu Sep 29, 2011 10:42 pm    Post subject: Reply with quote
Well I think it can safely be said that nobody ever died from radiation poisoning stemming from a radioactive Pentax lens.

I also kind of wonder what would happen if we started calling brick houses "radioactive houses" Laughing

Sorry to be a bit irreverent.


PostPosted: Tue Oct 10, 2023 2:35 pm    Post subject: Reply with quote
I have the pentacon 4/200 auto mc 6-leaf lens. The lens coating has a slight pink bruising. Should I be afraid? Is the lens radioactive coated? I searched a lot on the internet but could not find any data.


PostPosted: Tue Oct 10, 2023 5:27 pm    Post subject: Reply with quote
taskin wrote:
I have the pentacon 4/200 auto mc 6-leaf lens. The lens coating has a slight pink bruising. Should I be afraid? Is the lens radioactive coated? I searched a lot on the internet but could not find any data.
Pentacon 200/4 is not an exotic tele-lens. There was no need to use high quality rare earth glass.

But you can always measure your lens. There are many Chinese-made meters available.


PostPosted: Tue Oct 10, 2023 6:43 pm    Post subject: Reply with quote
y wrote:
taskin wrote:
I have the pentacon 4/200 auto mc 6-leaf lens. The lens coating has a slight pink bruising. Should I be afraid? Is the lens radioactive coated? I searched a lot on the internet but could not find any data.
Pentacon 200/4 is not an exotic tele-lens. There was no need to use high quality rare earth glass.

But you can always measure your lens. There are many Chinese-made meters available.


Thanks so much replay. The glass color made me uneasy. I love using manual lenses. Sometimes I think that such news is published deliberately. Capitalism loves to sell goods by scaring people.


PostPosted: Tue Oct 10, 2023 8:04 pm    Post subject: Reply with quote
taskin wrote:
...Sometimes I think that such news is published deliberately. Capitalism loves to sell goods by scaring people.


To my knowledge, the radioactive nature of some lenses was never used in negative advertising to get people to buy new non-radioactive ones.

Radioactive glass was abandoned largely due to health concerns for the optical factory workers who would be exposed on a daily basis to the waste products of grinding and polishing the glass, which is far more dangerous compared to carrying a finished lens around.

Heck, a couple of decades earlier they were selling radioactive toys to kids:

https://en.wikipedia.org/wiki/Gilbert_U-238_Atomic_Energy_Laboratory


PostPosted: Tue Oct 10, 2023 8:41 pm    Post subject: Reply with quote
RokkorDoctor wrote:
taskin wrote:
...Sometimes I think that such news is published deliberately. Capitalism loves to sell goods by scaring people.


To my knowledge, the radioactive nature of some lenses was never used in negative advertising to get people to buy new non-radioactive ones.

Radioactive glass was abandoned largely due to health concerns for the optical factory workers who would be exposed on a daily basis to the waste products of grinding and polishing the glass, which is far more dangerous compared to carrying a finished lens around.

Heck, a couple of decades earlier they were selling radioactive toys to kids:

https://en.wikipedia.org/wiki/Gilbert_U-238_Atomic_Energy_Laboratory


A very logical explanation. For my part, if I have any hesitation, I choose not to use it. I have a helios 44-2 lens and I will abandon both lenses. Thanks


PostPosted: Wed Oct 11, 2023 12:40 am    Post subject: Reply with quote
Anyone have a canon thoriumconcave. I will gladly take it off your hands. I have a lead lined adapter and not afraid to use it... Smile

People need to read the story of Marie Curie....


PostPosted: Wed Oct 11, 2023 5:11 pm    Post subject: Reply with quote
The radiation emitted by lenses after manufacture wasn't the problem. It wass the dust inhaled by workers in the glass factory. The tiny amount of radiation emitted by a a pentax lens is not going to increase your cancer risk by more than 0.001% (i made that number up, but your risk is minisculel If you use it as a normal person would. Keep it on the camera with a lens cap on unless actually taking a photo, or in a carrier of some kind). You might slightly increase your risk if you took the glass from the housing and wore it constantly as a necklace. Find an ACTUAL risk to spend your angst on, like drivers with cell phones in front of their face.


PostPosted: Wed Oct 11, 2023 5:53 pm    Post subject: Reply with quote
My post was more than a bit tongue in cheek. Radiation was discovered by seeing its effects on a film plate. So naturally a camera lens would be a great place for a significant source of radiation. People are conditioned to respond viscerally to the term radiation.
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