While I am waiting for my copy of the Sigma 180mm APO macro to arrive, I revisited your review of the Sigma 180mm f/2.8 EX DG OS HSM APO and I have a couple of suggestions as to what I would be looking for in a review that are not there.
I would want to know how well corrected the lens is in some detail, along with MTF charts, so I could see how sharp the lens is wide-open, and where any drop-off sets in, etc.
You quote figures from
www.lenscore.org. I can’t find where Lenscore points out how they arrive at their figures, individually, so that concerns me. Putting that aside, here are some Lenscore stats that I would want to look for in lenses. I chose the Sigma 180 that you reviewed, the very highly rated Zeiss Otus 85mm, and the classic Zeiss 100mm Makro-Planar as examples.
I will immediately put aside their Total Score for a lens because each of us would arrive at weighting probably differently from Lenscore, and the Sigma 180 does not rate that high comparatively anyway.
I would want to look at Chromatic Aberration, however, because one of the reasons I don’t use my copy of the Zeiss 100mm Makro-Planar is the abundance of CR with that lens. I see that the Sigma has even more CR than the Zeiss 100mm, so that is troubling.
I see that the Sigma has good sharpness, reasonable bokeh, but not great contrast, color, and some amount of distortion.
Of course, all these numbers have to be tested by actually using the lens, which is what I am doing by purchasing one, after reading your recommendation. I always have to see for myself. And your particular list of lens “amenities” differs from mine, so that parameter can’t be used to dignify a particular lens, except for our particular requirements, which I understand. I have my own list of what I “must have,” which I see are different from yours, etc.
So here is what I come up with. I understand, if I have Lenscore right, that lower numbers are worse and higher numbers are better:
LaCa LoCa Resolve Contrast
Zeiss Otus 85mm 1472 1853 1647 1469
Zeiss MP 100 931 895 1189 1087
Sigma 180mm 839 968 1078 1017
Bokeh Color Distort Total
Zeiss Otus 85mm 1729 1127 1034 1459
Zeiss MP 100 1062 951 1066 1033
Sigma 180mm 1050 964 995 982
The numbers for the Sigma are not totally encouraging IMO, but they do seem to bear out your what you like about the lens. My guess is that I will find this lens, for my work, sharp, with good bokeh, but sub-par when it comes to correction, contrast, and color. I will let you know when I have had a chance to use the lens. Thanks for pointing it out. I had ignored it up to now because of the reasons just mentioned, but it does sound convenient to use for some tasks.