Tested for Canon T3I(with adapter Canon/m42) see actual portrait tested photo. Aperture range - 1:2-1:16. Distance range - 0.5 m -10 m -infinity.Examples of photos taken on Helios 44 see the album. It can be used lens on a DIGITAL cameras. The lens is inspected with dosimeter, no radiation traces found. I'm glad that you are interested in lots that I sell. Wish you a good shopping.