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Radioactive Lenses and Everything About Them

There’s a lot of misinformation about radioactive lenses – from scare stories about growing an extra arm and getting cancer, all the way to saying that radioactive lenses are entirely harmless. The truth is somewhere between the two extremes and requires careful consideration. After all, these lenses contain radioactive substances, and we should treat them with some care. 

Like you, I wanted to be safe and understand how to deal with the radioactive lenses. I had so many questions: How to handle them? What damage could they do to me or the camera? Or maybe, I should give them away to a person from the forum offering to “take them away from me” to save me from harm? (Nice try, buddy!)

After reading countless articles, studies and books, I have compiled the answers to most common questions.

What makes vintage lenses radioactive?

Thorium and lanthanum, mainly. Camera lenses contain optical glass made with various unusual elements like lead, boron, calcium, lanthanum, and thorium dioxide. These elements have distinct optical properties, allowing manufacturers to create lenses of superior quality.

Both lanthanum and thorium dioxide are radioactive, although radioactivity from lanthanum is so small that it is not detectable without sensitive lab equipment. Lanthanum is only weakly radioactive because only 0.089% of it is lanthanum-138, a radioactive isotope and the remaining 99.9% is non-radioactive lanthanum-139. 

Exotic elements such as Thorium, Lanthanum and Zirconium are added to glass mixtures to create the high refractive indexes necessary in sophisticated lens designs. Selection of premium quantities of glass from the large glass pots, stringent spectrophotometric tests after stress and strain checks provide the valuable raw glass for ultimate use in lens elements.

Konica Hexanon Lens Guide, Konica Camera Company, 1972

History of radioactive lenses

In 1945, Paul F. De Paolis, from Eastman Kodak Company, filed a United States Patent 2,466,392 for Optical Glass, which introduced thorium and optical glass making properties. 

This application relates to glass having optical values in a range that is useful for the designing of optical instruments. Specifically, this application relates to such glass having an index of refraction for the D line (n) in the range between 1.65 and 1.68 and an Abbe value (v) between 52.5 and 57.0. 

In general, the glasses herein described are non-silicate and embody as the glassifier boric oxide in an amount between 35 and 40 per cent by weight; lanthanum and thorium oxides in substantially equal amounts, greater than ten per cent, of each; and barium oxide and either calcium or magnesium oxide.

United States Patent 2,466,392

Kodak produced some of the first radioactive lenses for aerial surveillance – the Aero-Ektar. Other manufacturers like Canon, Konica, Asahi Pentax, and others also used thorium in their lenses made between about 1945 and 1980. 

Manufacturers mostly used thoriated glass for the fastest, more expensive lenses, such as the f1.2s and f1.4s, but slower radioactive lenses also exist. 

Eventually, by the early 1980s, the thoriated glass fell out of use for consumer lenses – due to the factory workers’ health concerns and consumer radiophobia following nuclear accidents. Newer formulations appeared, offering similar properties without the added risk of radioactivity.  

Optical properties of thoriated lenses

The addition of thorium oxide, or thoria, to the glass increases refractive index while maintaining low dispersion. These properties are especially beneficial for making optical glass.

A high index of refraction means light travels slower within the glass, and therefore, changes its direction more easily. Lenses can have a lower profile, require less material and thus be lighter. 

Low dispersion, defined by Abbe number, allows lenses to correct chromatic aberration, ensuring the same focus is maintained throughout the whole range of colours in the visible spectrum, creating sharper images. 

Combining these properties enables lenses with excellent optical performance. 

What is thorium?

Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. All known thorium isotopes are unstable. The most stable isotope, 232Th, has a half-life of 14.05 billion years, or about the age of the universe. It decays very slowly via alpha decay, starting a decay chain named the thorium series that ends at stable 208Pb.

Wikipedia

Thorium is a naturally occurring, most abundant radioactive element in the earth’s crust. Thorium is relatively stable and has a half-life of 14 billion years.

Do radioactive lenses emit only alpha particles?

Not really. While it’s true that pure thorium decays by emitting an alpha particle as stated above, this is only the start of the long series of decays that emit alphabeta and gamma radiation until it ends with the stable isotope of lead. You can read it as such:

Thorium 232 -> releases alpha α -> becomes Radium 228, then
Radium 228 -> releases beta β- -> becomes Actinium 228, and so on.

The above decay chain demonstrates that thoriated lenses contain thorium and its daughter elements: radium, actinium, radon, polonium, bismuth, thallium, and lead in minute quantities, resulting from slow thorium decay.

What is bremsstrahlung radiation?

When beta particles slow down within denser materials, such as the barrel surrounding the lens, they create electromagnetic radiation by releasing a photon – an x-ray or gamma-ray. This secondary radiation is called “bremsstrahlung“, German for “braking radiation”. 

Most vintage lens barrels are steel, copper, or aluminium and produce tiny amounts of secondary gamma radiation. The heavier the shielding material, the more bremsstrahlung radiation is emitted. 

Due to how little beta decay there is, the resulting bremsstrahlung radiation is also minimal. Still, it’s worth mentioning for completeness to understand what types of radiation you could expect from a lens.

Source: Bremsstrahlung Safety Considerations 

Dangers of radioactive lenses

Glass dust and fine particles

Elements in the thorium decay chain are incredibly toxic and dangerous on their own and in larger quantities. However, the amounts present in the lenses are tiny and only exist for a short time. 

Breaking the lens will not “release” the radiation or the toxic elements which remain in the glass lattice structure. Nonetheless, it will contaminate the premises and make it easier to ingest or inhale small bits of radioactive dust.

Alpha particles can only penetrate a few micrometres of the outer layers of human skin and are harmless – as long as they are outside the body.

Alpha-emitting particles are significantly more dangerous inside the body. Ionising properties of the alpha particles cause damage when they are close to the cells — specifically, those in the respiratory tract and lungs and the digestive tract, stomach and intestines.

Ensure you do not smash, grind, scratch, or scrape the lens elements to avoid getting radioactive particles inside the body. As a good measure, I also wash my hands after handling them.

Eye damage from radioactive lenses

For uses of thoriated optical glass that are authorised under this exemption, the lens would be enclosed by other materials or there would be additional material between the lens and the tissues of an exposed individual, and only photon exposures would be of concern. However, in unauthorised uses of thoriated optical glass, such as eyepieces of optical instruments, exposure to the eye to alpha and beta particles also would be of concern. This concern is because of the proximity of the glass to the eye and lack of sufficient absorbing material between the source and tissues of the eye.

nrc.gov NUREG-1717 Page 3–288

Increased radiation exposure can cause cataracts in the eyes, therefore avoid needlessly exposing your eyes – wear glasses and don’t put radioactive lenses close to the naked eye when cleaning or handling them. 

Testing showed that simple eyeglasses effectively shield radiation emitted from the lens – only one-tenth of the radiation gets through. I measured approximately 3006 CPM through glasses versus approximately 28000 CPM at the surface. 

Radiation exposure from radioactive lenses

According to the research (below), radioactive lenses are relatively safe. We are regularly exposed to radiation from various sources every day, which combined give a more significant dose than the use of radioactive lenses would: 

  • Walking around outside in the sun (main contribution to the annual radiation dose)
  • Staying at home (Radon from the building materials, tiles)
  • Eating bananas (Contains potassium-40)
  • Eating brazil nuts (Contains Radium-226)
  • Flying on an aeroplane (about 2μSv/h of Cosmic radiation)
  • Getting an x-ray at the doctor 
  • Sleeping next to someone (the other person is radioactive to us (potassium-40)
  • Having a smoke detector (contains americium-241)
  • Having a granite countertop (uranium and decay products)
  • Smoking (releases radium, lead-210, polonium-210)

The total gamma energy released every second from the Carl Zeiss Tessar, on the other hand, was almost 32 MeV/s. The contribution from this for a photographer to the maximum annual dose to the whole body was calculated to be just 0.17 ‰. This is comparable to the increased dose from beta radiation. Thereby the beta and gamma radiation from the Carl Zeiss Tessar are equally non hazardous. These ratios are so close to zero that the conclusion drawn in this thesis is that there are no radiation related health hazards involved in the usage of any of the camera lenses measured.

An Analysis of Residual Radiation in Thoriated Camera Lenses. Jonathan Wäng and Viktor Henningsson, 2013.

How to identify radioactive lenses?

The most reliable way to determine whether the lens is radioactive is by measuring it with a Geiger counter. However, few people have easy access to one, and in that case, a visual inspection could be used as a backup.

Visual inspection can reveal hints that the lens is radioactive – radiation over time causes yellowing of the lens elements. However, ageing, as well as the composition of the glass, can also cause discolouration of the glass.

Looking through the lens at a white sheet of paper reveals the elements’ yellowing compared to the surrounding white paper. A significant difference in tone indicates a higher chance that the lens is radioactive. On the other hand, clear glass does not mean that the lens does not contain radioactive materials – it can go both ways. Radioactive lenses lose their yellow tint when exposed to UV light.

Is lens coating radioactive?

Lens coatings come in a variety of colours, which may appear yellow when viewed from an angle. The coating colour is not related to lens radioactivity and can be of any colour for radioactive, and non-radioactive lenses.

Some sources incorrectly state that the lens coatings are radioactive – that is not the case. The actual glass contains thorium – not the coatings. For example, Mamiya uses yellowish coatings on most of their vintage lenses, while only some of those lenses are radioactive.

Why do radioactive lenses yellow over time?

Radiation creates F-centers in the glass because radioactive decay displaces electrons, which cause the glass to take a yellow or brown tint. 

UV light can clear some of the yellowing. It may take up to 7 days of exposure to the sun, or UV light sources to lessen the yellowing. However, I like the warm colour cast in my photos, and leave the lenses as they are – it is a unique “feature” of a thoriated lens.

How to store radioactive lenses?

To avoid elevated radiation exposure – store the radioactive lenses as far away from yourself as reasonably possible. If you have a choice, do not keep them in the bedroom or locations where they are close to humans for prolonged periods. Even though the exposures are small, they all add up over time.

I measured a drop of radiation readings to background levels at about 1-1.5 meters away from the lenses. 

An aluminium case is a good option because it is a good shielding material for alphas and betas. Nevertheless, storage container material does not make as much of a difference in the dose rates as distance, so if you are worried – increase the distance between yourself and the lenses.

Measurement equipment

I measure my lenses using GQ GMC 600+ and GQ GMC 300E+ Geiger-Muller counters. GQ GMC 300E+ uses a more common M4011 GM tube, which is not very sensitive to Alpha radiation but detects Beta and Gamma. Meanwhile, the GMC 600+ uses LND 7317 pancake GM tube and is very sensitive to all types of radiation. 

Do radioactive lenses damage cameras?

All electronics are susceptible to radiation damage to some degree – digital cameras suffer from the formation of hot pixels on the sensor. 

The pixel size of the camera sensor is an important parameter with respect to radiation damage. From our experience we know that the sensors with smaller pixel sizes suffer more radiation damage. Also the exposure time can impact on the damage level: the number of hot spots increases with exposure time.

Response of the imaging cameras to hard radiation during JET operation (ScienceDirect)

I did a simple test to see how radiation might affect the camera sensor. I had a 90-second exposure with a lens cap on, so it would be a completely dark frame. Then I did the same with a non-radioactive lens. The radioactive lens left visible “excited pixels” in the image. You can easily repeat this test with your radioactive lenses – just ensure you disable noise reduction, because cameras will attempt to hide it, although it’s easy to see in RAW format files.

That is where the high-intensity particles hit the sensor. The pixels returned to normal for the next frame, and were not “stuck”, but I think it’s a good idea to remove radioactive lenses from the camera body and be on the safe side. Especially having in mind the above quote, which states that smaller pixel sizes are more susceptible – that’s specifically dangerous for our mirrorless cameras with many tiny pixels crammed onto small sensors.

More information about hot pixels and radiation damage to cameras:  on Hubble telescope camera, CMOS image sensors,  and on Reddit.

Posting radioactive lenses

Radioactive lenses do not usually cause problems for posting. I had various lenses shipped without any trouble, except from one time, when a Mamiya Sekor 55mm f1.4 was being shipped from the USA using the eBay Global Shipping programme. Global Shipping sent the lens back to the seller with a note stating that radioactive materials are not permitted. 

Are radioactive lenses still being made?

Current consumer lenses do not contain thorium – it has been replaced with newer formulations of glass, avoiding the radioactivity problem. The main concern was the factory workers’ health – nobody would want to polish and grind the glass and expose themselves to radiation. Also, people’s fear of radiation makes the finished product challenging to sell.

Interestingly, thorium is still used by the United States military in the state-of-the-art Global Hawk drones.

On June 21, 2017, a U.S. Air Force RQ-4 Global Hawk crashed near Mt. Whitney, which lies on the boundary between Sequoia National Park and the Inyo National Forest in California. It’s rugged, heavily forested terrain, and now the service wants someone to go in there and recover parts of the drone.

“The aircraft also has an optical lens which is impregnated with Thorium to enhance optical properties (similar to many commercial optics),” – stated the contract document. 

Thorium is a radioactive material and decays through alpha emission. If the lens has been burned or it has been melted the potential for alpha radiation exposure is higher. 

TheDrive

If the United States military chooses to use thorium to power their drone optics, perhaps we can say that it is still the best glass when absolute quality is required. 

Are radioactive lenses better?

Some of the most excellent vintage lenses ever made are radioactive. Is thorium to “blame” for their success, or is this only a coincidence? Difficult to say, but the fact that thoriated lenses are used in top-quality optical systems of military drones suggests the former.  

I tested quite a few radioactive lenses and fell in love with them. Mamiya 58mm f1.7 shows exceptional optical performance – images are sharp and contrasty with striking warm colour.

I am yet to find an optically poor example of a radioactive lens – quite the contrary – they are all excellent. 

Modern non-radioactive lenses surpass these vintage lenses in absolute sharpness and contrast. Furthermore, they usually feature more complex designs, with more elements and groups. However, the optical properties of the vintage lenses are more pleasing to some people – including me.

Thank you for reading

I hope you enjoyed this article and learned a lot about radioactive lenses and generally about radiation. If you have a moment, please leave a comment and tell me what you think – especially if you spot an error or inaccuracy. 

Disclaimer

This article is purely informational, and should not in no way be used as medical, health, radiation protection or safety advice, implied or not. Full Disclaimer.

Comments

36 responses to “Radioactive Lenses and Everything About Them”

  1. Stefan Avatar
    Stefan

    Hello.
    I would like to know if Hexanon 57mm f/1.4 is radioactive ? Did you have the occasion to test this version of lens ? I saw on YouTube that also 50mm f/1.4 is radioactive. Thanks !

    1. Eyewanders Avatar
      Eyewanders

      Yes. It is. Please don’t worry about it. This topic is endlessly overblown.
      Don’t hold it next to your naked eye. Don’t sleep with it. If you break an element, discard it and don’t breathe or ingest the particulate.
      Don’t worry on it.

  2. […] more (elsewhere).‘Radioactive lenses‘ on Lens Legend Radioactive lenses on camerapediaTreatment of yellowing (Old Skeeter on […]

  3. Charlier Luc Avatar
    Charlier Luc

    On your request, I will – briefly, which is hard to do for me – leave a comment. You described the whole setting in a PERFECT way. The information you give is complete, accurate and cleverly put. What I didn’t do (I will now) is disassembling lens and body when I don’t use them. I care for my gear! We live in weird world (and in the US more than anywhere else, but I’m refused access as I used to be “a dangerous communist”, which is not even true) and people are obliged to take preventive measures for dangers which don’t exist (insurances, politicians, law cases …). As you put it, the essence of the problem is the duration of exposure. In the case of photography as a hobby, the risk is down to … nihil. I’m quite convinced many cellular telephones (and antennas), wifi, micro-waves ovens, and radio-active waste storage places so much more so, represent far more serious health hazards. But they mean big money and bribery is all-ongoing. On the other hand, companies making modern photographic equipment don’t like the increasing interest in “old” gear, and I’m quite convinced they will lobby to minimize it. Let’s be clear, apart for the autofocus (comes in handy for birthday parties, bar mitzvahs, football matches, shooting your pets etc), who needs modern gear made of plastic, containing more electronic chips than optical glass, made with calculated obsolescence and out of fashion after 2 years?
    So thumbs up for your paper!

  4. decliners Avatar

    Thɑnk you for sharing your infօ. I truly appreciate your efforts and I will be waiting for your further write ups thank you once again.

  5. Henry Blood Avatar
    Henry Blood

    Can it be correctly assumed that a clear, heavy vintage lens is less likely to contain Thorium than a light weight vintage lens? I bought a Canon FL 135mm f 2.5 on ebay-heavy chunk of glass. Should I have any concern about this lens having radioactivity?

    1. Mantas Avatar

      Hi Henry, I would not associate overall lens weight with radioactivity. Most radioactive lenses come in the focal range between 35mm and 85mm. I don’t think the Canon FL 135mm f2.5 is radioactive, especially if it does not have the telltale yellowing of the optical elements. It would be nice to test it with a Geiger counter, to be sure. Either way, don’t fear the radioactive lenses – they are safe under normal use.

  6. PocketPixels Avatar

    Fascinating survey article. I recently learned about “F-centers” when I saw someone selling a small UV light to “de-yellow” old, radioactive Takumar Pentax lenses. You’ve pulled together a good collection of research here, and I enjoyed reading it.

  7. AH Avatar
    AH

    This is very interesting.
    So It’s best to try to avoid breaking these lenses.
    That is the most damaging thing one could do with these lenses,
    break them and do slow breathing exercizes above the broken lens.

    But on camera, they destroy sensor pixels? Lot’s on mirrorless, less on dslr.
    Or does it just kills pixels, mirror or not. Does light matters or do pikkels get killed.
    If you have a camera bag with a body in the middle, and all your nice sharp old glass,
    arround it. So in a way if you have some excellent but very powerfull radioactive glass
    in your collection. My lenses are in a closet, that has a small closet or 2
    And they go from wide to long. And again but then lenses from another mount system etc. It’s quite practical. Highest row the lenses I never use, like DKL mount.
    both ones, most Voigtlanders,
    Schneiders that look the same but not completely they don’t fit ultramatic so guess It’s for Kodak.
    Do not yet have an adapter, do not know if because I have all those lenses
    they all need to work on Sony. Mainly It means 3 or 4 more 50’s.
    Most of my lenses I can use adapted, I don’t use.

    It does happen I put body’s next to the lens cabinet.
    Do Takumars and other lenses, destroy pixels,
    just from being 50 cm or something from a digital body.
    Do they radiate in all directions all the time.
    Mainly longer periods, doing a shoot and having a radioactive in my kit,
    I’m not so worried. But a year long all my body’s next to my lenses.
    No Idea how many are radio active. I know have one or more.

    And if things matter, lenscap etc …
    But a more soled M42 adapter, the ring is in the barel, and It comes lose.
    I had two, one is loose.
    And adapters should be solid, not wobly and have multiple parts.
    But I buy the cheap one’s to test. If I use It. I will try to find a really good one.
    It’s the weakest part for dust, steam, water, sand etc … can enter.

  8. […] a distinct shine by bringing built-in Spotmatics to their stock. And we are not talking about the radioactive shine that this lens brings with it, which by the way has already been said many times that it is […]

  9. Ryan Avatar
    Ryan

    Hello, I would like to know if the Mamiya 35 Ruby 48mm lens is radioactive.
    q

    1. Mantas Avatar

      I don’t have one to test. Does it look yellow when you look through it?

  10. NeskoM Avatar
    NeskoM

    I read here on Camerapedia about radioacitve lenses and found their list of that.
    https://camerapedia.fandom.com/wiki/Radioactive_lenses
    I have CZJ Pancolar 50mm f1.8 and they say that – Carl Zeiss Jena Pancolar 50mm f1.8 “Zebra” (1964-67, up to serial number 8552600) is radioactive. I have Lens 8934568 and does it mean that lens are not radioactive? I could not find any other source and I need to know is this list and information for Panoclar correct and valuable? Can you help me somehow to get more info or get approval of this. It is very important to me.
    Thank you very much.

    1. Mantas Avatar

      Hi, it would not be conclusive without a geiger counter. However, your lens is later than the serial number, indicating it is has more chances to be non-radioactive. The information on Camerapedia is quite accurate. There three ways to test this: 1. Get someone with a Geiger Counter to test it. A lot of people have them, and they are not too expensive. You can get one for less than 100 euros. 2. Do a white background test – check to see if the lens has noticeable yellowing. I can always see the thorium yellowing, so it is visually evident. The Pancolar actually has strong yellowing, so if its completely clear – then it is not radioactive. Third – set camera on manual mode, high iso about 8000, exposure to 30 seconds. And make two photos – one with the pancolar, and one with a known non radioactive lens. Have lens caps on both. The radioactive lens picture will have noticeably more noise, and that noise will have bright streaks, almost like little meteors. Hope this helps!

      1. NeskoM Avatar
        NeskoM

        Thank you very much. I already did test with white background – it seem to me that my lens it is not radioactive. I will try third test, that you suggest, with long exposure but maybe I will find some Geiger to be 100% sure that it is not radioactive lens. You helped a lot, thanks ones again!

  11. Elizabeth Sheridan Avatar
    Elizabeth Sheridan

    I have a small leather box with F.Leitz wetziat embossed on the lid. Inside there is a square piece of uranium glass with no framework?

  12. […] Some vintage lenses were made with exotic elements like thorium, which eventually becomes radioactive. Image © Lens Legend […]

  13. Angelo Avatar
    Angelo

    Mantas, at first, thank you of all for the accurate and useful article on radioactive lenses.
    Really a great one!
    I would like to ask you for some informations.
    I own a very large number of view camera lenses:
    – Rodenstock (Grandagon, Sironar)
    – Schneider (Super Angulon Symmar)
    – Repro lenses (Apo-Ronar, G-Claron, Apo-Germinar, Apo-Tessar, Apo-Nikkor,
    Hexanon GRII) (heavy, a lot of glass, not very bright f/9)
    – Enlarger lenses (Componon, Rodagon, Computar).
    These lenses are low brightness lenses, generally f/5.6 or f/9
    All lenses seem transparent, not yellowish.
    The old Apo Ronars (4 lenses – 4 groups) have a slight amber color when viewed from the side but in the direction of the optical axis they do not show any color, the sheet remains white!
    Do you think all these lenses could be radioactive?
    What do you recommend me to do?
    I wouldn’t want to put my family members at any risk.
    Thank you in advance for your informations and your advices.

    1. Mantas Avatar

      Hi Angelo, thank you for your comment. The best telltale sign without the geiger counter is the yellowing of the elements. Look carefully, if you cant detect any yellowing when looking directly through it, then it’s more likely that it’s actually not radioactive. If the yellow color is more like the Mamiya Sekor 50mm f2 and only appears when viewed from the side – then it is just the coating, which is totally non-radioactive. However, I would genuinely recommend you get a geiger counter. It is so much fun to explore the world and see the invisible. Visit some rock formations? Going into a cave or old mine? Granite monument in the city center? Test them with the geiger counter, and find hot spots. It enhances a lot of activities for a curious mind. Get something simple like GMC-320 Plus, which is approx 100 EUR / USD.

      1. Angelo Avatar
        Angelo

        Hello Mantas,
        at first, thank you for your fine reply!
        I’ll I will follow your advice.
        I’ve seen some Geigers on the market.
        What do you think about GQ – GMC 500+?
        Will it work fine?
        Than you in advance for you precious advice.

        1. Mantas Avatar

          Hi Angelo,

          Yes, GQ – GMC 500+ will be absolutely fine! All GQ Geiger counters are good quality at reasonable price. I have the GQ 320+ v5 and the GQ 600+. 600+ is really cool because it detects alpha, beta, and gamma. Way more sensitive to small radiation changes, but also 3x the price, so could be surplus to requirements. But any model will register radiation coming from the lenses (and the surroundings), so 600+ could be overkill. I remember I bought 500+ as a gift for a friend, and he enjoyed using his.

  14. Richard Avatar
    Richard

    Hello. I want to ask about the following lenses : Minolta Rokkor 45mm f2 , Konica Hexanon 57mm f1.4 , Soligor 400mm f6.3 . Were radioactive substances used in them ? Thank you very much

    1. Mantas Avatar

      Hi Richard, thank you for asking. From what I managed to gather, all of the above are non-radioactive.

      1. Richard Avatar
        Richard

        Thanks Mantas

  15. Lonnie Elam Avatar
    Lonnie Elam

    Hi. Can you tell me if the silver Helios 44-2 KMZ lens with serial number 79125294 is radioactive? Thanks.

    1. Mantas Avatar

      Hi, no, Helios 44-2 is not a radioactive lens.

      1. Lonnie Elam Avatar
        Lonnie Elam

        Thanks, Mantas. I appreciate it.

      2. Lonnie Elam Avatar
        Lonnie Elam

        Thanks, Mantas. How about Contax Zeiss and Nikkor AIS lenses? Are they radioactive?

        1. Mantas Avatar

          Contax Zeiss – I have no information that any are radioactive. I have the 85mm and 50mm f2, both are not radioactive. Nikkor AIS – there are a lot of lenses there – I can not confirm whether there are any radioactive ones. Use the techniques in this guide, or try to google specific lens with the keyword “radioactive” added, to see whether someone has detected radioactivity. Nikkor is not usually the one mentioned, however, you can never know. The ‘usually’ radioactive ones are Mamiya, Yashica, Expensive Carl Zeiss DDR lenses, Expensive Canon FD lenses, some Konica lenses, Kodak Ektar lenses.

          1. Lonnie Elam Avatar
            Lonnie Elam

            Thanks again, Mantas. I appreciate it.

    2. Dennis Avatar
      Dennis

      Hello. How about hexagon 135/3.2 and others 135mm Konica lenses? Are they radioactive? Thanks

      1. Mantas Avatar

        Nope, Konica Hexanon 135mm lenses are not radioactive.

  16. Alan Alex Avatar
    Alan Alex

    Hi man, I just want ask do u know that the Konica 50mm f1.4 Hexanon AR (small apture f16) is made of the Th228? or Th something else? I cannot find the answer on website…

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