A single sheet of typing/printing paper or even the outer layers of your skin will stop an alpha particle. The lens caps are all you need. The risk to exposure is almost nil. Not grinding or exposing yourself to broken glass shards, micro shards, or dust is very good advice. Getting an alpha source inside your body is really, really, really bad juju! There is no need for special storage or keeping lenses separate from living spaces. Just keep caps on your lenses. - Thorium has a very long decay half life. Almost all Th is isotope 232 which has a decay half life of 1.405 x 10^10 years. Virtually all of the Th that was here during the time of the dinosaurs is still Th-232! Take a deep breath and relax. Yes, Thorium decay products do themselves decay by other mechanisms that will emit alpha particles, beta particles, and/or gamma rays. The Th-232 that decays by an alpha particle emission becomes Radium-228 which decays pretty quickly by beta particle emission to Actinium-228. Ac-228 decays in minutes to Th-228 or Fr-224 by beta or alpha emission … and so on. Ordinary dust in the lens will not become radioactive, but the risk of ingesting tiny bits of thoriated glass is a real hazard. When you check your lenses with a radiac the sensor is actually picking up the beta particles from the tiny amounts of Th decay products as alphas are non-penetrating radiation. The beta particles are more penetrating, but are almost completely stopped by about 1 meter of just air [@ STP]. The body of your camera between you and your thoriated lens will completely protect you from beta exposure. The risk is still very subcritical. Don't eat or snort thoriated lenses. /|\Gofiam P.S. - This is a great video: Radioactive Lenses Part 2 kzfaq.info/get/bejne/kMdxgrCB29K4kYk.htmlsi=umIew9uiF99EJtaf [~ 19.7’] Simon’s utak Note that "the internet", as stated in this video, is not the penultimate source of information on radiation safety.

I working on tech and my company had a rather entertaining issue that lasted for 18 months, took us forever to figure out. The lead that was being used in the manufacturer of our motherboards was contaminated with radioactive rhodium. Every once in a while the lead would throw off an alpha particle that would then disrupt the PCI bus of the motherboard, causing the system to crash. Fun times. I have zero concerns about casual use of these lenses.

While people debate whether they're dangerous to shooters, they overlook the adverse effect of having the hot rear element so close to the sensor. Had a Takumar 50mm attached to a nearly new X-T2 for a couple of weeks and it was a mosaic of hot/dead pixels afterwards.

Just spoke with an old friend of mine who is into photography as a hobby and welds for a career, and he said that he preferred thoriated lenses because of the optical properties and while looking for new lenses he takes a radiacode with him (gamma spectrometer to identify the isotopes in certain items) and even cracked lenses or lenses that need to be taken apart to be cleaned or fixed he said it isn't a big deal (back to welding he welds with thoriated tungsten electrodes aka red tungsten and he took his radiacode to his boots and pants and showed they were slightly radioactive from grinding the electrodes and he says that a weekly cleaning of the tungsten grinder is good enough for his shop and cleaning boots and pants is simple and easy) His point is that most of the claims of the video are false and that fearing your lenses won't do any good and fearing radiation is also a bad idea since most things that were made back in the day arnt harmful or dangerous (many boy scouts burnt thoriated lantern mantles in the last century but you don't see any related deaths from it and lots of people wore radium watches and many people ate off of uranium glazed dishes)

A must watch video Nigel and very well presented, along with the interspersed warnings and safety messages when handling these older lenses. Much appreciated, it's something I've never thought about, let alone even known about. Regards Rob.

Another excellent video Nigel!

Good information Nigel. I own several radio active lenses and use them often. I liked your tips about storing them in a metal box which I haven't done but you inspired me to do that. Thanks!

If the amount of radio activity would have been up to a dangerous level, the lenses wouldn't have worked… they would have ruined the film

It was usually Radium that was used on watches to create luminous indicators on the dial. Also on some telephones.

I'm a watchmaker and I own a basic geigercounter to test for radium in old watches. I also use it to test any old lenses that I buy. The only precaution that I take is not to leave hot lenses on a mirrorless camera whilst not in use. I've read that there are a few dangerous lenses like ones used in aerial recon but the radiation from consumer lenses isn't worth worrying about.

The hands of luminous watches were painted with radium. Unfortunately the ladies in the factories who painted the radium on got tongue cancer from licking their paint brushes

Nigel You need to watch Simon Utak review on radioactive lenses I have the Takumar 50mm 1.4 radioactive lens and dont worry about using the lens

Back in the 80's when I took a civil defense class on radiological monitoring, they told us that things need to be present in a nuclear reaction to become radioactive. Exposure to radiation doesn't make something radioactive.

ive always wanted to speak with lens engineers and designers of the past and ask about their calculations and changes in design changes in lenses, its fascinating stuff!

Of all the lenses I own, my Konica Hexanon AR 50mm f1.4 is easily one of my favorites and not just because it's a light bucket, although that doesn't hurt when shooting in low light!

A great video!

Everyone needs to listen to Kraftwerk’s Radio Activity song in the background to this. 👍📸

I don't know about Europe but here in America we do/did run fresh fruit especially berries under radioactive radiation to kill mold so it lasts longer. And most old stone buildings also give off mild radiation of alpha and beta particles.

I have two copies of the 57mm f/1.4 Hexanon that are not Radioactive at all. Tested both with a Geiger Counter and a scintillation detector.

Never parting with my 'hot Takumar 50mm F/1.4'' - after getting radiotherapy for cancer (for a delicate part of the body) I figure a few extra Sievert isn't something I'm concerned with. It's a lovely lens. Should probably stop sleeping with it under my pillow though 😏

The early version of the Pancolar 50mm f1.8 (up to serial number 855xxx...) is a fair bit more compact than the later zebra version which makes sense due to the different refractive properties of the glass. I believe two rear elements are thoriated in that particular lens. It seems to age to a lemon-yellow colour, unlike other thoriated lenses I've come across which tend to become almost brown in colour if left for long enough. The very early Canon FL 50mm f1.4 is thoriated but later versions of the same lens (which looks identical with the auto/masnual ring towards the front of the lens) are not, but in this case the change in construction didn't seem to make the lens more bulky.

Great video. I love my radioactive lens. One more thing I would recommend is not storing the lenses on your digital cameras long term.

I have checked my Minolta MC Rokkor PF 58mm f1.4 with my Geiger Counter and it is NOT radioactive. However, I have eight other lenses that are. The hottest is my FUJINON 50mm f1.4 Radioactive 3706 CPM, uSv/h 22.77 lens. I store these in between sheets of 0.5" plexiglass which stops the radiation.

Timex watches up to the 1980's were hot too in the past. The decals were coated with a radioactive paint. Come to think of it many WW2 aircraft had the same treatment with many of the dial decals which would glow in the dark which was a benefit I suppose.

Any of the KMZ lenses for my Zorkis?

Read a few years ago in either View Camera or Photo Techniques (both RIP) that placing a lens on enlarger paper overnight then developing would show fog if radioactive.

Thorium had to be dug up. Mined. Those workers...how did they fair over the years? Or the lens technicians at the factories? Of the few potential radioactive lenses I own, I keep my adapters on them permanently. (actually I buy adapters for all of my vintage lenses to keep things ready and simple) the adapter shields lateral radiation coming from the rear elements and I simply aim the lenses rearward in my drawer. I have heard you can bring these close to a radio, dial in an empty low frequency and listen for an increase in noise. It worked, and I retested using a modern metal lens and got no boost in noise. It's a bit spooky when you hear it.

I tried to not buy lenses which were suspected as radioactive… I sometimes cancelled purchase on EBay because of it…. Indeed I keep lenses in furniture on bed room so I m close to it all the time… the advantage dors n t worth i take even minimal risks… I can correct most of optical flaws in post production

I believe Kodak produced radioactive lenses in the 40s. More interesting for me is that Leitz wanted to experiment with Lanthanum glass after the last war. Their usual glass supplier didn't produce it .However they got supplies of the lanthanum glass from the British world renowned Chance Brothers of West Smethwick which was just outside of Birmingham. I'm typing this from about 12 miles from that area. I only have two radioactive lenses, both Takumar SME f1.8 55mm lenses. I bought an inexpensive Geiger counter and did a few basic experiments and found the detector alarmed when it was sitting on the lenses, move away a few inches and nothing detected other than background radiation.

I bought giger counter after I dismantled the lens to clean it out. Only the rear element had the brown tint.

My Asahi Super Takumar 50mm f1.4 Radioactive 2250 CPM SN 3237402. The Olympus OM-System Zuiko MC Auto-S 50mm f1.4 Black Nose Radioactive 460 CPM (Great Color Rendering).

Hello Nigel, it's not entirely true, that the pancolar zebra is radioactive. Only early zebra version of the Carl Zeiss Pancolar 50mm f1.8 up to serial number 8552600 were radioactive. They have a yellow tint in the glass. The later zebra versions don't have yellow glass. I've had a lot of them. Also the radioactive version. Sold them all 🤷🏻‍♂️ Greetings from Berlin, Denis

Wow! I never knew this.

I bought a CZJ Pancolar zebra lens. The seller advertised it as having been tested with a dosimeter which showed no traces of radiation. I took his word for it. Do you think I should have it checked myself?

Oddly enough not to scare anyone, canons old lenses were made for them by nipon kogaku tokyo japan. So even potentially nikon lenses may have been thoriated, based on what Ive learned over the net.

I had two mamiya sekor 50 2.0 lenses, from the DTL era - both visually identical, however only one was radioactive!

Having just seen your video I have tested the Konica Hexanon 1.4 that you recently featured, my copy using my Pudibel NR-750 giger counter at the mount end an average of 310-330 counts per minute and at the front 30-60 counts the back ground level 10 -15 counts per minute so we can see the main thorium coting is at the back of the lens, this giger counter dose not detected alfa particicals only beta and gamma and x-rays. I put the caps on the lens and wrapped in tissue and placed it in a tin (Steel) this reduced the count to average of 30-60, showing it is emitting gamma radiation so it needs careful handling as you stated I have test all my other lens and none are radioactive including my CZJ zebra pancolar which I believe above a certain number are not radioactive, I hoped this helps to clarify things. ps the Konica Hexanon 135 f3.5 is not radioactive

Thanks for a great episode! Thorium-232 has a half-life of 14 billion years, so don't expect a lot of specs of lead to build up in the lenses anytime soon! I have several radioactive lens (takumar, mamiya and zuiko), they indeed produce the most beautiful colors. Working with these lenses does not concern me at all, even if I worked with them for hours every day. And don't store beta-emitting lenses in lead, if the beta is high energy, x-rays can be produced (bremsstrahlung) as the beta particle is slowed down by the very dense lead. The x-rays are more harmful than alpha or beta radiation! Putting high-energy beta emitters under a plexiglass shield is best (no x-rays produced).

Can you make a video on vintage lenes that does Not have this thorium in it? Those colors are just amazing.

The "hottest" lens I have ever tested was an old Canon FL 28mm f/3.5, my Geiger counter screamed like never before. The measurement eclipsed those given for well-known thoriated lenses like the old Minolta 58mm f/1.2 by a factor of three!!

Have a bunch of pentax. I'm still alive so far.

Interesting. As a caveat to this journey of discovery, I suspect there's more radiation emitted from computers, mobile phones, & other domestic utility devices, & whilst Thorium is a radioactive isotope - de facto - one should not overplay its lethality; that is not to say you shouldn't be careful, but as you assert, common-sensical behaviour is the safest route to endorse. Superb images !

What is interesting is that my old one is SN 117492 and I measured it to be radioactive. The one I bought from you just now, is NOT radioactive. I need to research this to find where the cross over is for radioactive vs not radioactive based on SN Serial Numbers. I have a similar situation with Auto Rikenon 55mm f1.4 SN 52974 Radioactive 1682 CPM, 10.41 uSv/h and Auto Rikenon 55mm f1.4 SN 302757 not radioactive. What do you know about the Olympus history?

Just a point to the concerns about thorium radiations.. Thorium has an Half-life of 14 trillions years... it emits alpha particles that are nucleus of Helium not radiations but particles. They are stopped by pretty anything (they can travel only a couple cm on the air). the real health issue is if the alpha emitting material is introduced inside the body... so if you don't eat your lens you're pretty safe. :)

Thanks for the illuminating video! You can test a lens for radioactivity without using a geiger counter. Just shoot with it for some time, and if you discover that a new head is starting to grow out of your neck, the lens is probably radioactive. :) Cheers! :)

Most local fire departments have Geiger counters and will check your lens. Department of emergency services also has the equipment. Thanks. Mike

Virtually everyone in Europe got a lifetime's worth or more dose of radiation through food and water consumption after the April 1986 Chernobyl disaster😮 But If anyone wishes to go into eco-panic🤯 mode, check sources of ionising radiation in your standard home smoke alarm. My geiger counter goes off the scale if brought close to the active element (americium 241) in these devices. Common sense use of lenses incorporating high dispersion Thorium silicate glass is all thats needed to continue enjoying the safe use of these beautiful optics.😊

The earth's crust and the building materials - pottery as well - made from it contain Traces of uranium. This results in further radioactive elements being created one after the other via a “decay series”. One of these decay products is the radioactive noble gas radon. Concrete building materials have low natural radioactivity. Their total values ​​are significantly below the limit specified by the Leningrad formula. The radon pollution in indoor air caused by building materials is negligible with appropriate ventilation. The vast majority of radon in residential buildings comes from the soil. Every house should therefore be built on a tight concrete basement or on a seamless concrete floor slab, because this can effectively prevent the influx of radon from the ground. In addition to reducing the supply of radon from the soil, maintaining a hygienically required minimum air exchange rate of 0.8/h is of crucial importance for the radon concentration in residential buildings.

FYI, if one grind the glass into a powder and eat it, then it would be bad for one’s health ☢️ 😅

later variant of hexanon 50mm 1.4 is not radioactive, also has minimum aperture of f22 and 8 aperture blades.

Is the Zeiss Jena 35mm f/2.4 Flektogon in the clear? Don't see anything specifically saying they're radioactive, but other Zeiss Jenas are on the list...

I have 3 of the radioactive lenses on Nigel's list and it has never bothered me by using any of them. On Friday I had a full body bone scan preceded by an injection of 5 Greys of radioactive material to bind to the bones. I reckon that injection on its own would outweigh all the radiation emitted by these lenses over my lifetime. We are becoming too sensitised to any danger by a society that is increasingly frightened by any perceived danger, however tiny. Buy these lenses, use them sensibly, the dangers are really miniscule. George

No Canon Fd Lenses are Radioaktive? Not at all. The most famous of them all is the 35mm 2.0 Fd SCC. If you own one were the max aperture is 16 than its radioaktive. It goes down to 22 on the non radioaktive version. I think there were some early canon Fd lenses with the "Chrome Nose" that were radioaktive as well. What not many people seem to know is that the Famous 55mm 1.2 Asph. SCC is very radioaktive. I don´t know about the 24mm 1.4 SCC. asph and the 85mm 1.2 SCC asph. I never heard about a Canon nFD Lens that is radioaktive. But if you own an "old" FD aka with the breatchlock mount there is a good change. More so if you got the very early chrome Nose Fd´s.

Critical mass of Thorium-229 is slightly below 3000 kg so I guess it's safe putting my 55/1.4 Pancolar next to my 57/1.2 Hexanon 🙂

My Lord, I have taken to licking my Topcon lenses on a daily basis. They are amazing lenses.... Should I stop doing this?

My Asahi Super Takumar 50mm f1.4 Radioactive 2250 CPM SN 3237402. The Olympus OM-System Zuiko MC Auto-S 50mm f1.4 Black Nose Radioactive 460 CPM (Great Color Rendering). My Canon FL 55mm f1.2 1968 is NOT radioactive.

I’m always interested in hearing thoughts on radioactive lenses. My SMC Pentax 50mm f/1.4 is by far the hottest lens that I have, nearly double of the Super Takumar 50mm f/1.4 and the Takumar 55mm f/1.8 is much less than the 50 1.4. I have an early CZJ Tessor 50mm f/2.8 that isn’t radioactive and I have a Minolta Rokkor-PF 58mm f/1.4 that isn’t radioactive. I think that you just need to test each lens and go from there. Also I store my hot lenses in individual metal boxes just for peace of mind.

We are exposed to more radiation outside then these lens would give us, if you are afraid of these lens then I wouldn't go outside.

dont grind 'em and you'll be sound

I have not blown up yet… your Konica is radioactive,,,, plus the Pentax takumar 1.4… I can see a yellowing tint on your face…😂😂

One major concern, usually overlooked, is that using an SLR or even a DSLR the distance between the lens and the eyes is extremely limited ,so even when the type of the radioactive present isn't in the worse form and limited, remain a potential problem.

Radium on the watches

hey Zeno, could i interview you for a podcast? :)

Just not an issue. Far more dangers ot there. SMOKING for instance.

The ROKKOR PF 58mm 1.4 is NOT thoriated. I have two copies of that lens and neither are radioactive.

heya, regarding the storage and this is probably best checked in person, I recently measured my super-takumar 55 1.8 at 470cpm that value was only present at the rear element (which is sadly directly accessible so could be of concern) the radiation at the front element was barely above background radiation, a simple lenscap blocked all of it from the rear, therefore, at least for that one lens , a metal box is not necessary

A lot of you have giger counters 😮. Hopefully not flat earthers 😂

The super takumar 50mm f/1.4 8 element is not radioactive 😊

Metal, Paper or Glass will not stop amything. Plexiglass will. I use a few sheets of half inch Plexiglass in the water tight tube, two sheets on the bottom and two on the top. That does it. You really need to buy one of these GQ GMC-320 Plus Geiger Counter Nuclear Radiation Detector Data Recorder Beta Gamma x-Ray Test Equipment that costs about $100.

Don't be ridiculous, Metal, Paper or Glass will not stop amything. Plexiglass will. You really need to buy one of these GQ GMC-320 Plus Geiger Counter Nuclear Radiation Detector Data Recorder Beta Gamma x-Ray Test Equipment that costs about $100.

The disinformation that they 'only emit Alpha particles', 'a piece of paper stops them', blah blah needs go for good! Do your research on the decay process of Thorium, better yet buy a radiation meter/dosimeter that does not detect Alpha particles (the vast majority on the consumer market, if its not an expensive windowed type it will not detect Alpha particles) and test the lenses yourself. Old thoriated lenses are Beta and Gamma emitters. This is not a comment on the risk presented by using them, that is up to our own judgement (I use 2 myself), but whitewashing it with the unqualified pseudo-science that can be found all over the photography community does nobody any good (with the possible exception of those selling them).

The problem with these lenses are when people start opening them up to fix some issue in them.

I'm just effin annoyed of that clickbait thumbnail. We're to old for that crap, Nigel.

They cant kill you. Click bait im afraid. By the way you are very out of focus.