I compared the panasonic leica 25mm f/1.4 on the olympus omd em1 mII vs the sigma 35mm f/1.4 art on the pentax k-3. The sigma was sharper, had lower chromatic aberration, vignetting and distortion, both had transmission of 1.8, and yet both had a dxo lens score of 27. Please enlighten us. thanks.
I don't think DXO needs to enlighten you for this. Consider this: Lenses are some of the demanding precision manufactured products out there. No two lenses are exactly alike, not even the ones that come off the same conveyer belt. There is always going to be some sort of statistical deviation from the norm. Just like in computer microprocessors ,there is a tolerance allowed. So what does that mean? Give me a Sigma 35mm f1/.4 and I will find you a Panasonic Leica 25 f/1.4 that 's sharper and Vice versa. Don't believe me? Go look at the LensRental.com blogs where they test 5 of the exact same lenses for sharpness.