c4r0.skrzynka.org This is an SMC Takumar 55/1.8 that has a thorium doped lenses. Thorium was used to obtain larger refraction ratio and keep relatively low dispersion at the same time. Radiation was measured with beta shields removed, so both gamma quants and beta particles were counted. Dose equivalent rate is almost 30uSv/h (200 times background radiation in my area). RKSB-104 (GORIN) shows only 20uSv/h because it has two GM tubes on opposite sides of the casing, so only one tube was exposed to the radiation (the lens is 3-4cm in diameter). Polaron has two tubes also but both are placed on one side, so they both were exposed to the radiation.
Yep, it’s smc takumar (as I wrote in the vid title), and it’s radioactive as you can see in the video. So SMC Takumar is radioactive too (and there’s a lot of different radioactive lenses ofcourse). I’m not selling it, it’s my brother’s lens.
There is 5 different versions of the old Asahi Takumars
1)Takumar
2)Auto Takumar
3)Super Takumar
4)Super- Multi-Coated Takumar
5)SMC Takumar(rubber ring)
The one you tested is the latest on SMC Takumar(rubber ring) and it’s actually less radioactive than the Super Takumar one.
Super Takumar were produced from 1964 up to 1971
This SMC Takumar was produced from 1973 up to 1975.
The Takumar 1.4/50 (all versions) is a Leica Summilux 1.4/50 clone and one of favorite lenses . Perfect Bokeh
I didn’t know some f1.8 lenses were doped. I’ve got a Super-Multicoated Takumar 50mm f1.4 de-yellowing in my UV-light cooker right now.
so how dangerous is it to use my super takumar 50 1.4?
what is the limit of radiation that is acceptable?
Don’t worry, it’s not dangerous at all.
As such, not terribly dangerous in short exposures. But i wouldnt sleep with that lens next to my head. The radiation intensity is several hundred times background radiation levels. In other words, keep that thing next to your eyes for one hour, and it corresponds to a few hundred hours of background radiation exposure. Minimize exposure, just to play it safe
hi there, thanks for the video, what units are you measuring in on each geiger counter? i saw the 2nd measurement, 1947? could you post them up on comments? thanks.
When you read it as Sv/h it’s 30uSv/h (check the video description), but since it’s mostly beta particles I’m not sure if this unit is correct.
Hi again,
could you please explain why it’s not dangerous?
Is it true that using it for a few hours exposes you to the same amount of radiation as an international flight?
Hi,
If you hold the lens for an hour so that the rear lens (that one from the film side) touches your skin, your body, only around the plays where the lens touches your skin, would receive 30Sv dose. That is about 200x natural background radiation in my area, so your WHOLE body will receive the same dose after less than 10 days of normal living. The most important is that you never touch that lens actually so the radiation that reachs you is far far lower and only part of your body is exposed.
After all, such radiation level is nothing big. After one hour of flight at 10km altitude overall dose absorbed by your whole bodu would be probably higher.
@idoor Plenty.
But you must have it superglued to your eyes.
Hi, I got an SMC Takumar 55mm f/2. What you said below, about the mirror in the camera preventing the radiation effect on film, it holds true with DSLRs, right? Using this lens on my DSLR won’t damage the CCD or something? 🙂
Such radiation won’t damage your CCD at all. Radiation level under x-ray at airport is a LOT higher and it’s still not capable of damaging any part of the camera. The only thing that lens radiation could cause is some additional noise in the pictures, but I doubt it too.
улыбнуло =)
I just bought a SMC Takumar 50mm 1.4 and I didn’t realize it was radioactive until after I bought it. It’s kind of freaking me out. I know it’s only a little bit of radiation, but over time won’t it accumulate?
Also. What are the best precautions I should take when handling this lens? Maybe put a UV filter on it for extra caution? Never ever touch the rear element (that’s where the thorium is right)?
Do you think that putting the radioactive lens on my camera will contaminate my camera? Thanks
i tested my old Super Takumar 55/1.8 with geiger counter, no radiation! i don’t know why the later SMC version has radion …..
Seriously?! Some people are over reacting. Thorium emits alpha radiation, it can’t penetrate your skin or travel more than a few centimetres in air. The only way this lens would be dangerous is if you ground it up and injected it into your veins.
BTW touching the lens wont do you much harm.
@Christoff87
As you noticed, alpha particles (technically it’s not radiation) hardly penetrates anything – those are not alpha particles that are counted in the video 😉
Awesome!
@BenHughesStudios
Don’t stress about your lens. We live in a sea of radiation, and many things are slightly radioactive but harmless. Glass, pottery, bricks – all sorts of stuff. It’s sealed into the glass, impervious and won’t come off if you touch it. The radiation is so weak, it won’t even get through the dead outer layer of your skin. The amount you get from the lens is tiny compared to cosmic rays in the natural world. So relax, it’s safe, just don’t eat it. *grin*
As you all might know when an alpha particle is being emited, is randomly emited gamma radiation too (except Am241). But that gamma radiation has very limited energy (most of it is in kinetic energy of alpha particle). Everything detected in this video from those two instruments ( they use two russian SBM-20 tubes) is gamma and some beta radiation. The actual alpha particle radiation is a lot more intense then this readings shows 500-1000 times more intense.
How many goddamn gieger counters do you have? I want one.
just don’t put it in your mouth!
I can sale some dosimeters. If you are interested contact me.
Today I’ve got rardometer RKS 20.03 ‘Pripyat’ in excellent condition.
My contact: blasdoz@ukr.net