Originally posted by woodywesty I completely agree on the aesthetic merit of a lens but the hard fact is that it is nearly impossible to measure and compare along with the reality that "beauty" has many interpretations. The optical physics and related effects can be measured and compared between different lens's. That's really the only objective measurements we have to work with.
Review now include bokeh comparison. To be honest this is really basic but they look at the shape of the circle highlight, if there is oinion bokeh, if there is an outlining and they say if it buzy or smooth. Example if photozone.
Few include MTF20 that are more representative on actual micro contrast on top of MTF50 that is fine sharpness (the thing you need to look at crops to notice).
There is no serious discussion through on constrast, color rendition, hability to get 3D pop (or pixie dust) and qualities of rendering transitions.
While it is very possible to test scientificaly, I never see color accurary graphs except from DxOMark. Contrast is not tested scientifically neither while it could.
I remember an article explaining that when the FA ltd where designed, the design included non fully corrected focus plan as a feature as they recognised that in practice it allowed to get more pleasing image to the eyes. Thoses FA ltd are really made to get the best images. Not to get the best tests result. Even through FA31 has a stellar performance, even on charts.