​Is your camera radioactive?


Some camera parts, such as lenses and viewfinder prisms, can be radioactive, at least if they are produced during the 1970s or earlier. Back then, some optics manufacturers added thorium oxide to the glass to improve the optical quality, mainly to achieve a high refractive index and low dispersion. However, thorium 232 is radioactive, and as it decays with age, the radioactivity increases. Although thorium itself only emits alpha particles, its unstable daughter products also emit alpha, beta, and gamma radiation. Nevertheless, it is generally believed that the radiation levels typically are negligible and do not present health risks during normal use. 

The Cyberphoto Blog provides a list of known radioactive lenses and in some cases the measured level of radiation in terms of µSv/h. The list can be found here (translated to English here).  


Added 29/06/2026 09:12

Rollei XF 35

A measurement taken with a Radex 1503+ on my Rollei XF 35 with a Sonnar 40mm f/2.3 lens gives a reading of 0.81 µSv/h, not 1.46 as stated in the blog post referred to, which shows that there is some variability in the radiation levels. 

Added 39/06/2026 12:54

Yashica 35-ME

Also this Yashica 35-ME is radioactive. My Radex 1503+ shows 0.72 µSv/h.









Comments

Post a Comment

Popular posts from this blog

Real cameras make people nervous

Image
In the old days, before smartphones existed, not many people carried a camera with them, and when they did, it wasn’t a big deal. Almost everyone has a smartphone with a camera these days, but not many carry a rangefinder in a strap around the neck, which seems to make a big difference. Real cameras make people nervous. A few weeks ago, I took my Voigtländer Bessa R2m along on the dog walk to try out a new wide-angle lens from 7artisans. As I walked past a house where gardening work was taking place, I was suddenly stopped by a man in a mini-tractor who had caught up with me. He asked me aggressively what I was photographing and why. Did the neighbours disapprove of what he was doing? Did they want proof that something was damaged? I was quite taken aback and wasn’t prepared for such a discussion, but explained that I was just trying out a new lens. My dog sensed the tension in the meeting, fixed the man with his gaze and began to growl. The man then decided to drive back to the house...
Read more

A photo processed in coffee

Image
I've experimented with various developers, including Caffenol. This photo was developed using what's known as Caffenol CL.  The Digitaltruth recipe is described below. Caffenol CL Water  1000g Baking Soda   12.6g Sodium Hydroxide 6g Ascorbic Acid 10g Potassium Bromide 0.5g Instant Coffee 40g Development time: 1 hour. First continuous agitation for 30 seconds, then stand development. According to the blog caffenol.org , several other foods can also be used to develop film. Here are a few examples: Beerol 250ml Beer 2 tsp Washing Soda 1 tsp Vitamin C Wineol 400ml Red Wine 40g of Washing Soda 10g of Vitamin C Ajvarol 4 tsp Chutney 3 tsp Water 3 tsp Washing Soda 1 tsp Vitamin C Beetrootol 250ml Red Beetroot Juice 2 tsp Washing Soda 1 tsp Vitamin C Experimenting can be fun, but I’ll stick with Rodinal from now on.
Read more

Which is the best developing tank: stainless steel or plastic?

Image
Which tank is considered best is probably a matter of personal preference, but for several reasons I prefer the steel tank. It consists of fewer parts and requires less developer/fix than a comparable plastic tank, which I find important as I prefer single-use chemicals. The tank is also easier to clean, and the film, which is loaded from the centre, does not get stuck in the reel when this is moist – a common problem with plastic reels loaded by pushing the film from the outside of the reel.  A common complaint is that it’s difficult to load the film onto metal reels, and that’s certainly true of some reels. Personally, however, I use an LPL reel with a special type of film mount, and it’s very easy to load with film – a piece of cake, really.
Read more