Oh my God - also the Canon FD 55mm F/1.2 Aspherical is radioactive!!!!


The Radioactive Twins – The early blue AL version from 1971 and later S.S.C aspherical version from 1974 of Canon FD 55mm F/1.2

Lens Version Optical design Min aperture Mass
(g)		 Thoriated (radioactive) S/N range Radiation
dose rate  (*)		 Coating Introduced
FD55mm f/1.2  blue AL - 1.2 607 Yes - 9.14 μSV/h (rear element) 7.41 μSV/h (front) SSC March 1971
FD55mm f/1.2  S.S.C. AL - 1.2 575 Yes - 7.43 μSV/h SSC March 1973
FD55mm f/1.2
 S.S.C. ASPHERICAL - 1.2 569 Yes - 7.66 μSV/h SSC March 1975
*) Radiation dose rate has been measured from the rear end of the lens with several repeated measurements.


The aspherical blue AL 55mm F/1.2 on Canon new F-1