[Pavel]

Very fast primes tend to be very sharp in the center but the sharpness falls of (often rapidly) off center and in the corners. With D300, I wanted to compose in the field, often placing the visual focus off center, in the area of relative softness. That tended to limit the use of very wide apertures. I did not want to crop too much. With D800, there are so many pixels, that I can afford to place visual focus in the middle, use wide aperture and crop like crazy.

It took me a long time to unlearn placing visual focus in the center. Now I will have to unlearn placing it off center and learn again placing it in the center, at least when I shoot wide open with fast lenses. Never thought of that. Just sharing my thoughts....

[matthew]

This is a very good point.

I've never really done the 'fast prime' thing until this year. Until I bought my 50/1.4G lens, all of the ones that I used were quite uniform across the frame. But working with the 50mm wide open on the D800 has brought me to the odd circumstance of having to soften the centre of an image to avoid having one part of the image be distractingly sharp.



The massive cropping potential of the D800 has also made me change the way I work with vignetting. If I'm photographing wide-open then I expect to incorporate it into the finished image (as above), but if the crop is asymmetrical then the effect can be unsettling even if it isn't obvious. So now I need to assess how much and where I will crop an image, and will sometimes use software to remove the natural falloff and then replace it with a synthetic vignetting when I'm done.

[shuttertalk]

Interesting observations guys...