Perceptual Megapixel (DXO) - Printable Version

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Perceptual Megapixel (DXO) - Temporel - 09-11-2015



did photozone ever address the Perceptual Megapixel rating system used by DXO ?


I was surprised to see the poor result (P-Mpix, sharpness) the a6000 gets with some of the Zeiss lens eg: the Zeiss 16-35 f4.


If you do a comparison with a Nikon or Canon FF lens on an APS-C camera, you dont get a score as low as what the a6000 is getting even if you match the MP difference between the cameras.


You can see for yourself here: http://www.dxomark.com/Lenses/Sony/Sony-FE-Carl-Zeiss-Vario-Tessar-T-STAR-16-35mm-F4-ZA-OSS


I would love to hear what photozone has to say about the Perceptual Megapixel.



Perceptual Megapixel (DXO) - Brightcolours - 09-11-2015

DXO test "data" is very unreliable, to the extent that I pay no notice to DXO at all.

And that perceptual blah has hidden hocus pocus so that it can't be verified in any way.

Perceptual Megapixel (DXO) - Guest - 09-13-2015

I think DXO data is actually pretty useful, but the headline numbers aren't. The PMP figures are a great idea in principle, though I'd like  a little more transparency about how they are calculated (i.e. what the weighting between apertures and locations in the image field is: I have heard from them that it is weighted towards the best aperture, and towards the centre of the field, but not by how much)


Anyhow back on topic: most of these differences are between the strengths of the AA filers on the various APSC cameras. If you look at the Nikon 16-35 on the D800 and compare on different APSC cameras, it varies by much more than the MP amount explains, and tracks how strong the AA filter is. Remember in the case of the A7r and the A6000 you are comparing an sensor with no AA to one with.