A little local restaurant. A few tables and booths.
Shot with my Fujifilm XT-20 and a Tokyo Kogaku topcon RE Auto 35mm 2.8 manual focus lens in Topcor RE mount, adapted with speed booster for a true 35mm field of view and great night time performance.
On a whim, I decided to measure the radiation level of this Tokyo Kogaku (Topcon) lens. It is an unusual lens in that it doesnt have an aperture control ring. There is an aperture mechanism, but if is controlled by the camera (like a Topcon Unirex or Topcon IC-1). It is a sharp lens, but given it was the more affordable line (the RE was 50% more expensive), didn't expect Thorium was used for the lens. Then again, it is a 50mm from the 1960s.
Measured at rear element: 5.51uSv/h instant, 5.4 avg. Not background noise. So some front element (there are 6 glass elements in total in this lens) definitely was made with Thorium. It explains the sharpness. Also means I will have to keep it isolated for long term storage, and not on the shelf right next to me... I'll have to check the other Topcon UV lenses...