But surely the Poor / Fair / Good / VG / Excellent bars are for just that - making the (rough) comparison between the behaviour of different lenses on whatever systems? So long as I'm not trying to compare numbers, I guess I'm fine by just gauging the bar heights and getting an overall impression of the unit's performance.
P. S. I was thinking that this scale is a little misleading, because the part of the scale labelled "Good" may actually stand for quite soft - unbefitting a central performance of any semi-decent lens for sure. Thankfully there have been very few lenses with less than VG central performance wide open (in case of zooms, at least at most focal lengths...) The two that come to mind are the Canon 50/1.2 L and the Nikon 24-85 D.
P. S. I was thinking that this scale is a little misleading, because the part of the scale labelled "Good" may actually stand for quite soft - unbefitting a central performance of any semi-decent lens for sure. Thankfully there have been very few lenses with less than VG central performance wide open (in case of zooms, at least at most focal lengths...) The two that come to mind are the Canon 50/1.2 L and the Nikon 24-85 D.