DxO Mark and pentax lenses

Its all in the filters.

Put in sigma with Nikon DX mount which brings up the Nikon d7000 with a similar chip to the K-5

and the combination moves the Sigmas down significantly. the resolution rating is for the best aperture and the best resolution usually in the center of the field for that aperture.

I buy lenses for having no weak ratings rather than one sharp spot at one aperture.

The 16-45mm zoom has very consistent performance across all focal lengths.

http://www.dxomark.com/index.php/Lenses/Camera-Lens-Database/Pentax/smc-DA-16-45mm-F4.0-ED-AL/(camera)/676/(cameraname)/Pentax-K5

http://www.dxomark.com/index.php/About/In-depth-measurements/DxOMark-testing-protocols/MTF

shows the setup used. It produces a combined lens/chip rating.

http://quickmtf.com/index.html gives an explanation of the automated measuring method.

Cheers Pierre