I would not compare a Leonardo painting with a Leica lens, but it is a fact that photography is based on (oil)painting principles. This has been documented by H.P Robinson in his photography manual of 1869, and has been reprinted many times (Eastman Kodak 1971 e.g). I doubt that the similarities between painting and phtography show up in 35 mm. But in larger format it is certainly the case. In the last 20 years the high definition in photography is back again, and that is what Leonardo and other great masters just were doing. Imagine, the brush strokes of Leonardo in the Mona Lisa were less than 2 mm by one hair broad. And the in 20 layers!! This was High Definition 500 years ago. They painted with a magnifying glass. And most masters did it that way. Some present day photography is a revival of the painting long ago, but with a different technique. However, I think, this a the case with some large format photography. A Leica can show quite some detail, but not that much.