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 µ Sv/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...