johnctharp Offline Upload & Sell: Off
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p.2 #8 · p.2 #8 · Sigma 24-105mm f/4 DxOmarked: High End Performance | |
One of the things I've noticed going into DxOMark's scoring is stuff like transmission. When you really break down a lens' results, the scores start to make sense, but only if you need a 'one size fits all' score of a lens/body combination.
However, if you're looking at a particular aspect of a lens or set of lenses, you have to dig into the testing results quite a bit more. I saw that you mentioned the 1.4/50 ZE in another thread where DxO ranks it 'best' at F/2.8 while the 50/1.8 II ranks 'best' at F/1.8, and this does look dubious at first. What I see, though, is that while you can get acceptable sharpness from the shifty fifty wide-open, and thus not give up any light, the Zeiss is not acceptably sharp wide-open, and thus must be stopped down. Since transmissivity goes into the overall score along with sharpness, CA, distortion and so on, it makes sense for the 'best' aperture and focal length of a given lens to be the fastest aperture where they find 'acceptable' sharpness, whatever that means.
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