How radiation affects digital camera

Henri Rantanen 0

I recently visited the Chernobyl exclusion zone the pictures of the damaged reactor of the power plant were slightly faded, I suspected it was due to the background radiation.

I figured it was easy enough to test how radiation affects digital CMOS-sensors so I irradiated my Nikon to see what kind of effects would I get.

Exposing the camera to radiation

I built a rig to expose my camera to different levels of radiation. Two radioisotopes were used as radiation sources, Cobalt-60 which is a strong Gamma-emitter and Cesium-137 which emits Beta-particles. These yielded the highest activity levels of my samples.

Samples of different radioisotopes

In the measurements I used my trusty Russian dual-tube RADEX RD1706 Geiger Counter with a custom sticker in it.

Rig contained a lab stand holding the Geiger-counter, camera which had its sensor set the same height from the table and a laboratory scissor jack to rise and lower the isotope sample.

Testing rig with dosimeter and the DSLR

The gamma-emitter was covered with 8 mm aluminium sheet to block any Beta and Alpha-particles from reaching the sensors. For Cesium-137 paper envelope was used as an Alpha-shield. Lens was removed from the camera and replaced with thin plastic body cap.

I took 11 measurements with both isotopes from different heights swapping the lab-elevator under the the Geiger-counter and camera. Pictures were taken in RAW-format with 30 second exposures to maximize the amount of interference in the shots.


Radiation produces spots in the image that are caused by high energy particles hitting the CMOS-sensor. When the ray is absorbed by the electrons in the censor, they get exited and soon release their excess energy as a flash of light.

Unless the radiation is affecting the control and processing circuitry of the camera, anomalies seen on the images are not caused by ionizing radiation.

Natural background + DSLR electrical noise  
Gamma source + DSLR electrical noise

Read the whole lab-report (in Finnish) »

  1. Camera did not take any damage during the tests
  2. Ionizing radiation can be picked up by camera’s CMOS-sensor
  3. High energy particles cause bright dots in digital images
  4. Remember to switch off camera’s manual mode if not using it
What do you think of this post?
  • Interesting (70%)
  • Like (20%)
  • Awesome (10%)
  • Dislike (0%)
  • Surprising (0%)
  • Useful (0%)
  • Boring (0%)
  • Sucks (0%)

Leave a Reply

Your email address will not be published. Required fields are marked *