D800 focus with 1.4 prime lenses is very variable and inaccurate

is that AF module cannot perfectly cope with the vary shallow "effective dof" coming out from the combination of 36 megapixels and large apertures. Lenses with "short throw" cam, like the 14-24mm f2.8, suffer as much as, if not more, faster aperture lenses.

If you repeat single focusing at the same target, you will notice that at each half shutter press the distance scale changes a bit. That causes the focus plane to move forwards and backwards, in a way that may throw subjects out of focus depending on lens dof. The effect is magnified by the 36 megapixels.

I came to accept that, in the end. It is not fixable, it is a camera feature.

Best regards,

M

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Mauro
http://www.maurobenphoto.com
http://www.makropress.com/
http://www.romephotographyworkshop.com