Leica worked out the best prime lens focal length line-up for documentary photography and photojournalism in 35mm years ago and it remains the benchmark and role model for other lens makers to this very day. The only focal length missing from this lens collection is 40mm, which Leica made for the Leica CL rangefinder camera which was later taken over by Minolta as the Minolta CLE with 40mm standard lens as well as a 28mm and 90mm lens. Too many contemporary lens makers leave out 28mm and 75mm lenses and their equivalents for other sensor formats. Why? Both these focal lengths are the most essential for documentary photography and photojournalism.