Some thoughts about lens testing…
Many websites supply scientific tests about lens resolution, vignetting, chromatic aberrations and such things. When I started photography I was very much enthusiastic to check this charts, especially interested always about resolution figures.
There are some aspects though which is hard to measure, but in fact these factors are almost the most important in lenses to have the best picture quality.
This two factor is colors and contrast. After checking many lenses, most of them can seem the same as others but there are some lenses which is truly exceptional. Up to now I tried to test the best lenses I can get my hands on. The difference is usually colors and contrast which the lens produces, together with image sharpness. In this area I see special ED or (UD in Canon), flourite or Super ED exotic glass lens elements play a big role, usually these lenses are better. Some lenses can produce extraordinary resolution figures but without nice colours and contrast, just don’t cut it. Other lenses has not so high resolution figures but in real life the pictures are just better.