The lens dude needs a KZfaq channel. I feel like his job is really interesting

A couple of years ago you did a video saying that not everybody liked what you upload. Well sod them! I find what you upload fascinating. It may be trivia but its interesting trivia. Keep them coming.

What a unique view into a very unique industry. Many thanks to Matthew for his wealth of knowledge in the industry.

Dude that's awesome, I had no idea about Thorium oxide being mixed in with those lenses. Love your channel, always learn something new

We sold my father's Voigtländer Bessamatic 35mm SLR camera fitted with the 1959 Voigtländer Zoomar 36-82mm f/2.8 lens. I believe this lens is radioactive, but I didn’t realise until after it had been sold and before I purchased my Radiacode 102.

Getting close to 100k! So cool that you got to hang out over at Duclos!

Thorium doped lenses are fascinating. I have one in my crackle collection. Made by Nikor in the 1970s I believe. It's on one of home made antique television cameras high up on the book case out of harm's way. I like the look on my guest's faces when I crackle my little home made Geiger counters for them. My 1 gram uraninite sample is impressive enough. Mother's old radium dial alarm clock (double bagged in polyethylene) is better yet. But, those are nothing next to that lens.

Every video I have watched of yours has taken the fear out of radiation as a whole because I have a better understanding of it in general. It has helped me to understand Fukushima, Chernobyl disasters as well as the fallout that goes with it. The reaction the public has to Nuclear power let alone radiation as a while is completely different than it is in communities such as Hanford and I am understanding it more as time is going on and educating myself. Unfortunately there are people who choose to stick their heads in the sand that you can try and educate but it is a lost cause. Thank you for what you do, I appreciate you.

Yes, you can use a UV light to clear the brown cast from a radioactive lens, or set it out in the sun for a bit. Equally effective. Won't do much for the radiation, of course, but I'm glad you put the actual risk in perspective. If you've ever had a CT scan or underwent any kind of heart procedure. An abdominal CT scan, for example, is the equivalent of 500 chest x-rays!

You have a very unique channel. I have been watching you for about 6 months now. But made a new YT profile and had to come back and resubscribe. Keep up the great work. You content is very interesting, and you are getting better with every video. Definitely a niche corner of the world, but you are right where you belong. Awesome job, Drew!!

I have an old (circa late 1960's) Pentax Spotmatic 35mm SLR. The normal lens that came with it has a thoriated rear element. My wife used to teach high school chemistry, and we would go to flea markets with a Geiger counter to find odd peices of radionuclides. We would especially look for old vaseline glass and Fiestaware with uranium in it. You can actually tell in what time frame it was made by how hot it is. If it was from the 30s and earlier, it would be much hotter than if it was made in the 40s or later. In the early 40s, the government sequestered all the uranium for the Manhatten Project so that they could separate all the fissionable U235 out of it for the devices. After that, you could only get depleated uranium for civilian use.

I can’t explain my curiosity in this. It started much earlier than your channel was even conceived. Please keep this channel flowing as much as you reasonably can do. Fascinating stuff

This is called, electron wells in crystal structures. It also turns salt brown when exposed to radiation. I exposed a salt container to a co60 source and it was really brown. Heat it a bit and it will glow and go clear again

Woah what an awesome video! So cool seeing these old parts and lenses.

Interesting video Drew, thank you. I had no idea thorium was used in lenses to improve their optical properties. I find it remarkable how radioactive material was commonly used.

its amazing how many everyday things are radioactive thank you Drew i really do enjoy your videos

Thanks for taking us along!

Too much fun! Thanks for posting this video!

Every upload, I learn something. Good stuff.

this is one of the most interesting videos youve done so far. Great work

So interesting, Drew. Great video 😊

Another interesting experience. Thanks for sharing!

I get amazed every time you upload a video man. Hoping you hit that big 100K this year, you deserve it!

OK, this one was fun on sooo many levels. Good job!

I’ll have to watch for those

Just wanted to thank you for all the videos. I recently started collecting uranium glass, and watching your videos has put it all in perspective for me, and I feel completely safer. Some of your items I wouldn't mess with or collect, but I find it incredibly interesting! Can't wait to see what you have coming up. 🤓

this is fascinating

Fantastic video Drew! From someone that has been behind many lenses in the 80s, I've never seen anything like that.

Fascinating! Thanks a lot!

Mate what a fantastic video. Learned so much about lenses and why you would use Thorium in the lens. Crazy... the more you know.

that was super interesting !!! didn't know that even existed !!!! osum content keep them coming !!!

Thank for this fascinating video.

Had no idea that old camera glass was radioactive... Very interesting...

Dude I'm glad I saw this video. Thanks for that email response. Excited to buy a Radiacode 102!

Thanks Drew

I love thorium lenses. They are quite a nice tool to calibrate the Radiacode if shifted for some reason. I have two camera lenses disassembled and kept the radioactive lenses for demonstration purposes.

Loved this!

My pentax spotmatic lens is the most radioactive thing I own, didnt know it produced X-rays though!

I’ve been working in optical thin films for over 20 years. We used to use thorium fluoride to produce optical coatings many years ago. In fact we still have a container of the material which definitely lights up my Better Geiger. It could be just the optical coating ( which allows for greater transmission of light through the lens) that is setting off your radiation detector.

Not sure about that lens, but the camera lenses with the thorium are highly sought after by photographers because they have very low chromatic abberation. You do however need to use and develop the film promptly. One easy way to make the noncemented lenses clear again is to heat them slowly, the brown tinge actually glows a deep red color as it disappears too. ❤

Interesting and educational video. I recently acquired some depression era plates (somewhat gold colored in soft light but can look slightly green in brighter light). The spectrum data from my Radiacode suggest it too has a Thorium parent.

Super interesting video. Those clickers are like a laser beam when the detectors scream. They’re focused pitches, so they don’t necessarily change the average loudness, but they may be dangerous for ears when the volume is up. Unsolicited, apologies, but I highly recommend using eq and/or a focused multiband compressor plugin in your video program to tame the screamers. Cheers, Daniel

I definitely have a few camera lenses that are radio active too, crazy considering how radio active some of them are (considering how small the optical difference the thorium in the glass makes)

GREAT VIDEO!!!!!!!!!!!!!!!!!!!!!!!!!!!!

That’s some really cool history once again. It’s even cooler because you have some experience in this industry and I assume you know what you are looking for. 👍🏻👍🏻 ☢️

That Cooke beeped like a hot particle from Chernobyl that landed on my rain coat. I still remember my Chemistry teacher with Geiger counter, how his face turned grey like ashes. But there was no fallout in that area, because Finland did not want to anger the USSR. If I calculated correctly, one week worth of close proximity would have been enough to end you. I never saw that raincoat again.

Super interesting video. Thanks for making sharing.

Very interested in optics and lenses so this episode was very enjoyable on many counts, thank you! Something maybe in the future I'd be interested to see is an episode on safe storage of radioactive objects. Have several items such as aviation instruments, fiestaware, mantles, etc. I've seen and heard both extremes from people handling items very irresponsibly to folks who go a bit overboard with safety. Would love to hear your balanced view.

Just found your channel about a week ago. I’ve been fascinated with radiation for years now, but I’m amazed by your videos. Amazing how strong the smoke detector was! Scary stuff

Radioactivity among old cinematography stuff can come from unexpected sources one tripod that was radioactive was traced back to a surplus sale that should have been discarded instead. The tripod in question was used to film a nuclear engine in operation out at jackass Flats

Radiation is so fascinating

nice vid drew

Honestly I never knew that about lenses, my tinnitus is loving this though. 🤣

Wow Drew... absolutely fascinating! I had no idea. So I searched and found the wikipedia "Thoriated glass" page and learned (maybe missed it in your video) that glass is thoriated to increase the refractive index. Very interesting. Article also said some thoriated glass can be as much as 30% thorium (which seems like a typo - but since I found it on the internet it must be true :-). Thanks again Drew for your wonderful content.

thank you this is an incredible show. It was great getting to see all those lenses learn about the company and I did go and look up the equipment that you were talking about from your sponsor. Excellent I do have questions about the little geiger counters which were not talked about on their website but I might like to ask you about it since the manufacturer is in Greece and there is not a phone number.

I found a small woman’s watch at a yard sale. It was not in a watch case just in a small plastic box. I flipped the top open and checked it with my SBT-11A modified fs-5000 and the counts shot up to 130,000. Lady was shocked and said she had no idea and was thinking about making it into a necklace. I bought it for the $3 she was asking.

How to never deal with mold on your lens again! (I absolutely love your content btw)

Thats one hot lens 😮 🔥

I actually picked up a clock at the thrift store and it actually set the alarm off on my GMC-300E, at a nice 9.06 usv nothing else in my collection has set off the alarm on that before, lol, all radium numbers and dials on it

I’m guessing the yellowing is because the thorium atom gets a recoil once it emits an alpha particle. I think you can correct it by heating the lens to a sufficiently high temperature but that might damage the lens. The alpha particle probably causes crystal defects as well.

فيديو مليئ بالمعلومات المثمرة.

To get the yellow out, try heating it up in the oven and then letting it naturally cool so that it doesn't crack. I'm not sure how hot we heated up the Harshaw TLDs we used.

It's kind of like how the Bromine (fire retardant) in plastics makes them turn a brownish-yellow. Can be remedied by coating with Volume Cream Hair Bleach and placing under the sun or UV light and then washing off.

might be worth doing a vid on storage of radiactive objects.

hmmmm I think I have the same lens.. Was from an old studio camera. Will go check it now

I just wanted to note that a dental x ray only delivers 10uSv of effective dose, but that's the equivalent 10uSv of uniform exposure to the WHOLE body. The absorbed dose to the face will be much higher (hundreds of uGy at least). You're off by an order of magnitude or two by comparing this lens to a dental x ray every 10 minutes.

Thorium was a common additive to GTAW/TIG/Heliarc welding electrodes; I still have boxes of 2% thoriated rods.

Well, at least I now know to avoid buying any Angenieux lenses for my old Pentax. last thing I need is to be holding a radioactive lens when I have already been subjected to a massive amount of radiation in my lifetime. I used to be part of an oil well cased hole inspection company and we used some fairly radioactive sources in our regular operations. On top of that I was very ill ten years back and received several CT scans in a relatively short period of time so I would much rather err on the side of caution. And the crazy thing about it is that while I was inside the machines getting scanned I could feel sharp pains from the scan as it rotated around my body, nothing exactly in one specific spot but they were throughout various spots in my body, so those scans weren't exactly pleasant either, and the techs refused to believe me that it was causing me pain, thinking that it was psychosomatic, instead of real pain. so I avoid radiation now if at all possible. Although, the possibility of relief from pain that so many people claim happens when they go into that mine you went into for a video you did a couple years back, I think it was in Colorado or Wyoming, it was converted into a health treatment center but was definitely an old Uranium mine with a definite radon gas presence. I would be tempted to give that a try as I suffer from a great deal of pain every day. So much so that when I get actual relief from my normal pain that it is like a drug of the purest kind....being pain free for some of us is more addicting that what even the most powerful narcotic can bring. and I would know because when I was in the ICU at the Hospital my pain doctor who is also an anesthesiologist made up a mescaline injection for pain relief after my surgery, and total pain relief is more powerful than that!

Very interesting concept of radioactive elements affecting scatter rate makes me wonder exactly how

Big lenses are fun! Interesting video, Thx. Did they have any Oldelft Rayxar lenses? Not for projectors but for Xrays as you would have guessed.

Thorium is a common addition to Glass up until I think the 70s. Takumar AKA Pentax use a lot of these. You can usually tell from the yellowing

I wish you could walk the nature trails at the retired Rocky Flats Department of Energy site near Golden Colorado.

Grinding these must have been "fun", back in the day....

I just sold a Pentax Asahi Super Takumar 50mm F1.4 lens that has the same coating! They are incredibly sharp

I've been studying ionizing radiation and into it for a while, but I'm relatively new to collecting radioactive items, so could you do a video about collecting radioactive things? Maybe some tips and tricks to hunting for stuff in an antique shop, or some things to make it easier? It would be really helpful! :) PS Awesome video! :D

Hey Drew, I love these videos, but can I make one request? Could you please put an EQ notch on the beeper for for gadgets? They are disproportionately louder than the rest of the audio. Thanks!

I have 2-3 Thorium laced photographic lenses. It was used to create more clarity, at that time. Subsequently, thorium was dropped from the glass line up for photographic optics manufacturers. It was extremely popular back in the 30s and 40s by Kodak. My samples are radioactive but in no way more so than those green glassware plates and cups from the 50s. If you have such lenses, the evidence is clearly found with a Geiger counter. Short having such a detector, it is seen by the yellow tint within the glass. It is reversible, if the lens is out in a high ultraviolet environment-for example, out in the sunshine. But it takes a long time to reverse. The earlier Kodak lenses wind up completely worthless for color photography because the glass winds up as a dark brown color-like looking through a glass of Coca-Cola! My radioactive lenses were made by Nikon in the early 1970s and are the 35mm f/1.4 Nikkor lenses. Your title of this video is highly CLICK BAIT insofar as suggesting they can be used to produce an x-ray. Another significant source of ionizing radiation comes from silk mantles used inside a Coleman lantern. They take newly manufactured silk mantles and dip them in a solution of thorium and after they dry, the mantles burn much brighter. The thorium never burns off. If you want to set off a Geiger counter take one flying with you. Above about 20,000’ the ionizing radiation from space penetrates the thin skin of aircraft. The higher you go, the hotter it gets! That’s why many pilots have received a sizable does of radiation during a career of flying. The flying career exposes one to more radiation than anything you will get as a dental technician, or working in a nuclear power plant. We see a lot more miscarriages in stewardesses, as a result.

That looked like fun. Been into photography since 1995, and it's very interesting to see this and your other video. None of my lenses are radioactive, but I could leave my Canon in a fiesta bowl over night. 😁😶🤔 Could a fiesta bowl screw up the electronics in a cell phone if you kept them together for whatever period of time?

So… would it be any help to surround the thorium-bearing lenses with flat discs of leaded glass?

Your videos are always super interesting mate, keep them coming :) Been thinking about getting a Radiacode or something myself now to hunt second hand stores and find interesting radiated things outdoors over here in Australia.

Sounds like those lenses are hotter than some of the mines you have taken us through….

It is interesting that thorium was used to manufacture camping lantern mantles to make the light output brighter.

Hey Drew, I was just thinking to myself. If you ever run out of radioactive material… No pun intended, you could always just film the desert and it’s hidden treasures. You have that special something that people like to watch on television. I hope to walk around the desert someday. I drove through there once on my way from California to Massachusetts. I spent some time out in Arizona. Not enough though. Anyways brother hope the universe is treating you and your family well. Be safe looking forward to more videos!

I would love to get my hands on some thorium especially in its metallic form. Pretty interesting how commonly radioactive elements like thorium and uranium were and still are used! ☢☢

Drew what do you think of the radiation reading of Auritz Burguete, Spain where "Windy" reports a reading of over 25,000 nSv/hr? A typical city has reading of 50 nSv/hr. Some places in England near Windscale have a 300 nSv/hr reading.

I would be interested if you showed the spectrum shown by the radiacode for these lenses (and also used the dose rate from the radiacode so we can see the actual human corrected dose rate instead of cps).

My first "good lens" was a Pentax 50mm f/1.4 Super Takumar, probably the highest production of any lens with a Thoriated element.

I knew about lenses made with thorium oxide but I didn’t know how common it was. Were these lenses used in many 35 mm cameras, or just the high end cameras? The tungsten filaments in auto headlights contained thorium oxide but at some point they stopped using them. You should be able to get a reading on old auto headlights. I cannot find the year they stopped using thoriated tungsten filaments but I’m guessing between 1980 and 1990. The filament will be a distance from the glass so I don’t know how much above background one of these would be.

My grandfather was a projectionist (retired about 1980). I wonder if he knew of the radioactivity

Very cool stuff! I never knew these existed. My nephew is in this industry, I should ask him. Did you buy anything from them?

Hi Drew , i watch your video and bought a radiacode 103 , i am perpare for testing my vintage camera lens ,but as google said there is only alpha particles form thoriated glass which mean radiacode not working for detect thoriated glass?cos radiacode detect gamma and xray, am i correct?thanks

how far in the lens was that element? My angenieux 18-270mm tv lens is radioactive on the rear lens but not much on the front lens. How far in was that highly radioactive element ? These lenses are about 14 inches long so just wondering if its inside near the middle?

Hola Drew, just followed the Radiacode link as want to purchase. What is the difference between the 102 and 103 models? I live 10kms from the 1966 Palomares B52 nuclear crash and do a lot of hiking in the area, so would be interesting to see what is detected 👍

I wonder if they measured the CPM as quality control parameter during manufacturing?

Did you have any issues getting the Radiacode software running on Windows?

Would love to see this lens in a cloud chamber.

Is the browning in the lens' the reason some older tv shows have a brownish tinge? Or am I making a connection that doesn't exist?

I sent you a picture on Instagram of a canon scope that had thorium doped lenses last year. Did they make rifle scopes with thorium lenses?

I bet those shop workers looked up from their work when your detector start screaming !!!

Hey drew, what is the cheapest alpha detector that you can buy, I looked up that b20 figuring they were like 300 bucks lmao.