Metering issue with D800 and 105mm f/2.8 VR
using my D800 and recently acquired 105mm f/2.8 VR macro lens for some non-macro shooting (focal distance about 5m), I realized that pictures taken at f/2.8 are significantly darker (underexposed) than photos of the same subject-matter taken at smaller apertures. This happened both in matrix and spot metering mode. From f/4 and down the exposure was pretty consistent. I have not noticed similar metering variation with any of my other lenses. Apart from the inconsistent metering, the lens delivers very nice pictures.
Is this behaviour normal for this particular lens or should I see it as an indication of a defect of some kind?