Nikkor Posted April 27, 2014 Share Posted April 27, 2014 Viewfinder eye-pieces made of Thorium? Now that a entirely different topic. If you can point out a camera maker actually using thorium in an eyepiece now, tell me and I'll sue, and shut down the company. As I said when it comes to lenses, it is NOT an issue unless you lick it for hours everyday, for months, or eat it. But with an eyepiece, we already do that (keep the eye piece in contact with an exposed part of our body, the eye) so that WOULD be dangerous to your cornea, conjunctiva and even retina. Not carcinogenic but mildly dangerous, especially if you don't wear eye glasses for example (the radiation would never penetrate the glass) I am truly concerned about this, does anyone actually really make such thing? I think they used it in lab stuff (microscopes,etc...) but I wouldn't rule out some old 70s cameras. Quote Link to comment Share on other sites More sharing options...
Junior Posted April 27, 2014 Author Share Posted April 27, 2014 Viewfinder eye-pieces made of Thorium? Now that a entirely different topic. The viewfinder info is just a part of the article, as an example. It's not the only subject of this, so it's not "an entirely different topic". It's full of infos about Takumar. So read full text before answering "Mr Saadwi the physician"… Emanuel 1 Quote Link to comment Share on other sites More sharing options...
Sean Cunningham Posted April 27, 2014 Share Posted April 27, 2014 I think they used it in lab stuff (microscopes,etc...) but I wouldn't rule out some old 70s cameras. Still, the quoted part above is conflating the entirely different issue of hypothetical eyepieces with the subject of the thread, which is thorium in certain classic lenses. This same site raises the issue but also puts it in perspective, the part he's leaving out because that's not compatible with the hysteria he's trying to create. Given that we don't hold the lens up to our eyeballs and shoot pictures out our butt holes the OP is trying to make a fairly known issue into a bigger hazard than it actually is. Respecting these lenses and being mindful of their peculiarity doesn't impose any kind of radical hardship as far as storage or handling goes. The subject being photographed receives, potentially, more direct bombardment of radioactivity than the operator. Put a UV, ND or anamorphic adapter on the front of one of these and, voila, problem solved, now nobody is getting rads. Since the radiation coming off these lenses cannot penetrate most other surfaces and doesn't travel far. Say a lens is radioactive and you get a reaction from people. Oh, that's bad! Except "radioactive" is a fairly meaningless term given bananas, potatoes, carrots and other foods are naturally radioactive. So are lots of plants and rocks everywhere and compounds found in our own bodies and potentially well water if you live in a remote, rural region. Okay, so they're radioactive. What does that actually mean? So you dig further and it's Thorium-232. Oh, that does sound scary! So you dig further to see what kind of radiation it gives off: 232Th decays by alpha decay with a half-life of 1.405×1010 years, over three times the age of the earth and more than the age of the universe. Oh my, that does sound bad! Okay, so what is "alpha decay" and what does it take to protect yourself??? Being relatively heavy and positively charged, alpha particles tend to have a very short mean free path, and quickly lose kinetic energy within a short distance of their source. ...go on... In general, external alpha radiation is not harmful since alpha particles are effectively shielded by a few centimeters of air, a piece of paper, or the thin layer of dead skin cells that make up the epidermis. Even touching an alpha source is typically not harmful... ...oh, so, wait a minute, what's the big emergency? Oh, there really isn't one. Don't ingest the lens, or smash it or lick it or hold it up to your eyeball without a camera being between it and you and then if you want to feel really good about yourself, put something on the front so you're not giving other people harmless, momentary rads when you take their picture, especially if you're doing macro photography of their eyeball. Turns out, alpha decay is so easily shielded it's an option as a power source for cardiac pacemakers. edit: of course, all this assumes there's nothing else in there but the thorium. The thorium isn't really scary. Information on something else being in there might change the situation. Quote Link to comment Share on other sites More sharing options...
JohnBarlow Posted April 27, 2014 Share Posted April 27, 2014 So how many lenses like these do you need to fry up some bacon and eggs on set? Quote Link to comment Share on other sites More sharing options...
fuzzynormal Posted April 27, 2014 Share Posted April 27, 2014 It's Thorium-232. Oh, that does sound scary! It's a big scary word next to the scary "radioactive" word. Oh nos! I'm gonna die because science is stuff I don't comprehend and I just KNOW it can sometimes be bad, like vaccines. So how many lenses like these do you need to fry up some bacon and eggs on set? One. Heat it up with fire and put bits of food on the glass. Of course a regular frying pan might work better. Just make sure that's it's not cast iron. Too much iron leeching off cookware is bad for you. On second thought, just don't eat. It's dangerous. Stop breathing too. In fact, why are you even trying to live? Don't you know you can't do it forever? What exactly are you trying to accomplish? Why are we even here? What's the point? Does god exist? 42. Quote Link to comment Share on other sites More sharing options...
Guest Ebrahim Saadawi Posted April 27, 2014 Share Posted April 27, 2014 I wanted to get to the bottom of this, I spent the night on the phone discussing the matter with a group of friends, who are specialists in both physicist and medical fields, and they all seemed to come to a conclusion similar to what Mr. Sean Cunningham is saying in the previous post. I'll try to break it down as simply as possible (and excuse my English it's not even my third language): 1- Thorium is an alpha particle - emitter, and the radioactivity of alpha particles is very short in life-span. They are blocked completely by almost anything. A filter in front of the lens, a lens cap, a piece of paper, and of course a camera body made out of magnesium alloy. And if they managed to somehow escape all of these and come in direct contact with your body, the outermost thinnest layer of epithelium of dead skin will completely block it. BUT there is that small percentage of your body that's not shielded with skin layers: 1-Your eyes 2-Your Rectum 3-Wound openings 4-Oral gate Thus, alpha particles can be hazardous if came in contact directly with one of these parts., and this can occur in the below activities: A-Holding the lens in contact with an eyeball, for a long period of time, regularly. B-Holding the lens in contact with the rectum, again, for a long period of time, regularly C-Holding the lens in contact with an open wound, for a long period of time, regularly D-Ingesting, and/or inhaling the lens. *We all agree these are all highly unlikely to occur with photographic lenses, but if you do any of these activities mentioned above, then yes it IS dangerous. I advice you do it with a modern non-radioactive photographic lenses. That’s why I was concerned when viewfinders were mentioned, because they do come in contact with our eyes, for a long period of time, regularly, hence hazardous. So, I still want to know if any camera makers actually do such thing. If it’s true, this is what we should be discussing. Lastly, even if one of these situations did occur, the effect it will have on health is minor. X-rays and UV rays are much more hazardous to health, they are highly penetrating to skin, and even when the human body comes in contact with them, in an x-ray scan, or the exposure to sun, for example, it’s rarely an issue even then. (Think Ultra Violet Keratitis “snowburns†that occurs when a large amount of a much more hazardous ray than alpha particles (UV) comes in contact with your eye- even in that case, I personally rarely prescribe medication for it, just flush your eyes with water or a saline solution for a couple of minutes and you’ll be fine) --------------------------- Conclusion: 1- Old photographic lenses radioactivity do not impose a health risk on most users, as they are shielded from the radiation. 2- Old photographic lenses do impose a health risk on those who are involved in A, B, C, and/or D activities mentioned above, and it’s advised they should use modern lenses to avoid redness, itching, burns or any discomfort that might occur from the alpha radiation. 3- Eye pieces containing Thorium do impose a health risk on most users, as they are not shielded from the radiation. Thus any company currently producing such products should be questioned immediately. -Saadawi Quote Link to comment Share on other sites More sharing options...
fuzzynormal Posted April 28, 2014 Share Posted April 28, 2014 Holding the lens in contact with the rectum for a long period of time regularly These are all highly unlikely to occur with photographic lenses. Speak for yourself. Now I'm really worried. Julian 1 Quote Link to comment Share on other sites More sharing options...
nazdar Posted April 28, 2014 Share Posted April 28, 2014 Worst thing when speaking about radiaoctivity and health hazards is making any fun of it and detract it. This topic is complicated and really few understand it fully so its natural that people easily jump on any rumors and tend to start panicking immediately. But that is not their fault. So instead of getting angry and act like dumb its better to explain everything and make it clear what its really dangerous and whats not and under which conditions. Its same like with filming and cameras, you have a lot to learn to fully understand whats going on, except that you work with visible part of spectrum. Btw Thanks to continuous Fukushima disaster, hot topic is now Pacific sea food, tuna fish etc. Who is still eating Pacific catch? It may have low radiation and you can stop it by piece of paper, but if you eat it, it will stay in you and you will be exposed to the low emissions for the very long time, probably rest of your life, and that can be pretty serious. Cumulative radiation is harmfull. Some company started to make camera sensors which can see radioactivity together with visible light http://japandailypress.com/mitsubishi-creates-camera-that-can-see-radiation-goes-on-sale-in-feb-1618531/ Btw if you have smoke detectors in your home or an office some of them contain radioactive Americium and you are sitting, sleeping, eating and working under it all the day long. ;) Better to buy optical ones.http://www.world-nuclear.org/info/non-power-nuclear-applications/radioisotopes/smoke-detectors-and-americium/ Quote Link to comment Share on other sites More sharing options...
sunyata Posted April 28, 2014 Share Posted April 28, 2014 I was waiting for that one fuzzynormal.. boom bang folks. Once when I was a teenager working on a 63 valiant, I got a huge face full of genuine early 60's vintage asbestos brake dust, then I found out it can cause cancer:) Did that stop me from continuing to work on old cars? Uh, no, but now I wear a mask. It's always better to be informed. It's not about what is worse, Fukashima, trans-continental flights, white paint, old brakes, or Thorium lenses, you want to avoid carcinogens as much as possible over your lifespan because it ALL accumulates. I don't think junior is "fear mongering" or trying to create "hysteria" Sean, maybe it's slightly overstated in the thread title, just do your own research. No need to ridicule the guy. Quote Link to comment Share on other sites More sharing options...
fuzzynormal Posted April 28, 2014 Share Posted April 28, 2014 I was waiting for that one fuzzynormal. I go for the easy jokes. It was either a self-depricating aside or a fart quip. I went with the former. Quote Link to comment Share on other sites More sharing options...
hmcindie Posted April 28, 2014 Share Posted April 28, 2014 Atleast NEVER take that radioactive lens too close to your eyes. You might develop cataracts way sooner than otherwise. Quote Link to comment Share on other sites More sharing options...
Junior Posted April 28, 2014 Author Share Posted April 28, 2014 What I early said in this wild forum: What the specialised guys told me yesterday is that even if it doesn't stay around your neck or on your chest for hours, (or under your bed), it's still dangerous because of lost dusts. One of the main risks is to let it fall and break it for example. Vacuum cleaner wouldn't help you there… Once ingerated (accidentally of course), Radium 232 is known to stay on bones and in liver for life! & I'm only here to prevent (...) But each one is free. That's all folks! But what I didin't explain too is that if let it fall and break it would be the worse situation, just have it near (getting old and disaggregating) is near the same, but slower. Once you get some inside of you it's forever. Really risky isn't it? So if I continue to argue here, it's because I'm afraid that a guy reading your last positive posts finds the wrong reassuring sentences he would be looking for and gets less carefully being less informated. Emanuel 1 Quote Link to comment Share on other sites More sharing options...
Emanuel Posted April 28, 2014 Share Posted April 28, 2014 When the same few people I read here blatantly replying OP will have a solution for one of the major health problems of modern times aka cancer, please advise your community on topic. I am sure Nobel Committee shall have in consideration your effort. Excelent topic Junior, kudos for your initiative and congratulations to Andrew for such valuable forum, as well, to those posts really adding some worthy discussion even if from the same (un)usual suspects, if but only when so ;) Thanks on behalf of all non-Adolf grateful readers, Emanuel :-) Quote Link to comment Share on other sites More sharing options...
enny Posted April 28, 2014 Share Posted April 28, 2014 First cold war then terrorist, then bird fly then meteorites from space and now i can get killed by my lenses then GOD DAM it i just completed my collection of yachica ml lenses DAM DAM IT TO HELL. But seriously guy how bad is this problem my? my anxiety is spiking just like that Geiger Counter PS One reason i am not freaking out is i work in granite industry, fabricating granite and all kind of stone from quartz, granite marble we polish it grind it cut it you name it and some of that rock is radio active. My self i been working in that industry on and off for 10 years now full time. There is shit load of dust when we grind you can cut it with knife, i do wear respirator but there are guys like my supervisor my brothers who been doing it for over 10-20-30 years my boos for over 35 years. All of them are heavy smokers some don't wear respirators at all. My boos has been doing it without respirator for over 10 years at beginning breathing all that dust he is doing just fine we all go every second weekend and play indoor football AKA soccer for 4 hours with no problems. What i am saying is everything those days is bad for you even food and water we eat drink now lots of it is fear mongering and thanks to media it has made it so bad that some of us only eat organic food and drink water from mountains of Tibet. Do you live in a basement or have finished basement guess what radon is collected in the basement second leading cause of lung cancer do you have tiles in your house there you go its radio active . Remember good old TV Cathode ray tube and all that Xray that we been exposed to did any of us die? According to this internet source, Carol W. LaGrasse, P.E., member Adirondack Branch Advisory Council of the American Lung Association of N.Y. State, 1986, "For a person smoking 1 1/2 packs of cigarettes a day, the annual radiation dose to the surface of bronchial cells at bifurcations is the equivalent dose to the skin from taking 300 chest X- rays per year. let's do some math. Average (global) human dose per year is approximately 300 mrem. Total radiation absorbed from focusing and/or holding the lens attached to a camera ≈ 2 uSv/hr. 2 uSv = 0.2 mrem So, that's ≈ 0.2 mrem/hr. 300 mrem / 0.2 mrem/hr. = 1500 hrs. of exposure So, if you used the lens attached to your camera for a total of 4.109 hrs. a day, every day, for a year, you would add another 300 mrem to the global average 300 mrem, to get 600mrem. If you wear a pacemaker, you are getting another 100 mrem Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted April 28, 2014 Administrators Share Posted April 28, 2014 A day at the beach is more dangerous than owning 100 Thorium coated lenses. We should be thankful the Thorium makes for a sharper picture. The only reason Thorium was replaced in manufacturing was due to hazards related to the actual manufacturing with large quantities of the stuff, day in day out. I don't intend to grind down the rear element of my Asahi Takumar and drink it in a cocktail. So I guess I'll just keep using it. andy lee 1 Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted April 28, 2014 Administrators Share Posted April 28, 2014 Btw Thanks to continuous Fukushima disaster, hot topic is now Pacific sea food, tuna fish etc. Who is still eating Pacific catch? It may have low radiation and you can stop it by piece of paper, but if you eat it, it will stay in you and you will be exposed to the low emissions for the very long time, probably rest of your life, and that can be pretty serious. Cumulative radiation is harmfull. This is a great thread, has been wonderful to read and actually thank you to the original poster because it is well intentioned and interesting. Thank you even more though to the people curious enough to do some proper research, because hysteria is everywhere today and it is not constructive. Most people don't have any real threats effecting them, so they invent them. This is human nature. One example is the complete decommissioning of nuclear in Germany due to a one-in-1000 year 5000 mile away tsunami which happened to one plant on the coast of Japan combined with a magnitude 9 earthquake. Clearly nuclear is very dangerous in such circumstances. As it would be in your kitchen. So the Germans decided to kill their perfectly safe nuclear industry and become dependant on expensive, ugly windmills and Russian nuclear power (a whole lot less safe) because of the threat of a magnitude 9 earthquake and tsunami! Logical?! About as logical as being scared of a 35mm F2 :) andy lee 1 Quote Link to comment Share on other sites More sharing options...
Pascal Garnier Posted April 28, 2014 Share Posted April 28, 2014 There's no such thing as a "perfectly safe nuclear industry". Try saying that to people living in a 5000 mile radius round Tchernobyl or Fukushima. There's not a single nuclear plant which has insurance, simply cos they can't find an insurance company willing to cover the risk. In Belgium, with it's "perfectly safe nuclear industry", 2 of the 3 plants have had to shutdown due to tiny microscopic cracks in the plant's core. Noone inside the perfectly safe nuclear industry knows how to solve it, or what to do with the core and the rest of the plant. The plants will very probably never startup again. Nuclear energy creates a wonderful legacy for our children and great granchildren : nuclear waste. Which will be here at least as long as we are. Plenty of it was dumped in the oceans, is leaking now and we have no idea what to do with the rest of the waste that's stored all over the planet right now. There's plenty of sustainable alternatives, the nuclear lobby is heavily subsidized (even after +40 years of development they can't function without heavy national and supranational funding). A recent EU report was censored because it mentioned how nuclear and fossil energy are subsidized more than sustainable forms of energy. I'd rather live nearby an ugly windmill than within 1000 miles of a nuclear plant. Huuow and Brellivids 2 Quote Link to comment Share on other sites More sharing options...
enny Posted April 28, 2014 Share Posted April 28, 2014 Ahh guys actual here in Ontario Canada we have shit load of windmill and guessssss what some yahoo told the people that they cause cancer like power electric cables. And now there is this crying north of me farmers want it down and families that live near by. But if you ask me they look so dam cool from a distance but i gues whet ever we make people will find something bad to say about it. indeed. Life is a process of dying. The point is, the radioactivity of these lenses under normal usage has such a minimal effect on your total yearly radiation that it is entirely pointless to worry about it. Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted April 28, 2014 Administrators Share Posted April 28, 2014 There's no such thing as a "perfectly safe nuclear industry". Try saying that to people living in a 5000 mile radius round Tchernobyl or Fukushima. There's not a single nuclear plant which has insurance, simply cos they can't find an insurance company willing to cover the risk. In Belgium, with it's "perfectly safe nuclear industry", 2 of the 3 plants have had to shutdown due to tiny microscopic cracks in the plant's core. Noone inside the perfectly safe nuclear industry knows how to solve it, or what to do with the core and the rest of the plant. The plants will very probably never startup again. Nuclear energy creates a wonderful legacy for our children and great granchildren : nuclear waste. Which will be here at least as long as we are. Plenty of it was dumped in the oceans, is leaking now and we have no idea what to do with the rest of the waste that's stored all over the planet right now. There's plenty of sustainable alternatives, the nuclear lobby is heavily subsidized (even after +40 years of development they can't function without heavy national and supranational funding). A recent EU report was censored because it mentioned how nuclear and fossil energy are subsidized more than sustainable forms of energy. I'd rather live nearby an ugly windmill than within 1000 miles of a nuclear plant. Yes all correct. But still no tsunami or magnitude 9 earthquake in central Germany. Odd. Quote Link to comment Share on other sites More sharing options...
Huuow Posted April 28, 2014 Share Posted April 28, 2014 Yes all correct. But still no tsunami or magnitude 9 earthquake in central Germany. Odd. lol what, you still need your earthquake? Quote Link to comment Share on other sites More sharing options...
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