On 9/17/2012 12:53 AM, David J. Littleboy wrote:
"PeterN" wrote:

Ohh... Unless you typically mount f/1.4 lenses and shoot
focus chart wide open, there isn't a focus problem. If
you do shoot charts, there might be.


I am leaning towards the D4 because of its better high ISO usability and
higher fps rate. Although it has less pixels than the D800, the pixels
are much larger.


That's probably the wrong way to think about it. If you look at the
prints, the apparent noise in the print (even for smaller prints) will
be more a function of the total sensor area than how that area is
divided into pixels. Both sensors are capturing the same total number of
photons for the same scene.

Obviously, four small pixels have four times as much circuit noise as
one fat pixel, but you can get the effect of pixel binning by applying
stronger noise reduction to the higher pixel count sensor, and the
circuit noise is pretty small compared to the shot noise at high ISO.


I could be wrong and oversimplifying, but noise reduction software works
on a principle of color blurring.
The main reasons I am going FF are that I do severe crops and wide angle
images. I have often wind up with a fraction of my original image blown
up to 12x12, of 12x18. I like the fast burst capability for animals, and
the high ISO for high shutter speeds.





--
Peter