[Fkid]

Hello,



I've recently purchased a D800 and a 50 1.4 G.



Doing tests of the same scene through all the aperture values (ex: 1/250 f1.4, 1/125 f2.0, 1/60 f2.8 etc..), I noticed some changes in luminosity (apart from 1.4 and 2.0 due to vignetting).

I supposed it should be a small problem with that copy of the lens, so I returned it to the shop and get another one.

And the new one has exactly the same behaviour. This is:



f4 - f5.6 - f8 all perfectly equal. I choose them as the point of reference.

f2.8 a bit lighter than the reference.

f1.4-f2.0 a lot darker, due to vignetting so I accepted it as normal.

f11-f16 exactly equal between them, but both a bit darker than reference. (1/6 of a stop).



So if the same behaviour repeated in two different copies I guess it should be a design thing.



I've discarded any issue with the shutter speeds, d-lighting is off, etc.



Ok, the changes in luminosity are small, but I've never seen something like this. Since digital I've always shot canon, mainly with L glass, but I think, except wide open, all lenses I've shot keep the luminosity without changes along all aperture range.



So: is that normal with the 50 1.4 G?



Thanks