>Very interesting comparison. Of course the D800 is cropped >down beyond the level of a D7000 if I read the thread >correctly, so it has a disadvantage as compared to the D4 >(which is clearly better, more detail and less noise).
That's one of the things that makes comparisons difficult to discuss -- it depends on what you think normal. These are a screen shot where each is 1:1 on the screen, so a pixel is a pixel right and left. But in a "normal" D800 image, uncropped or cropped the same as a D4 image, you have a lot more pixels. So 1:1 is about the worst the D800 can show compared to the D4, as full frame to full frame what noise it has is averaged more widely over 2-3 times the pixels.
I really wasn't putting this up as anything scientific, but curiousity, having been struck by the coincidence. The full resolution JPG's are at the sites in the OP if interested, but they are edited and noise reduced, when I get home I'll pull the original unedited and post.
Not based on this or testing but just on "gut feel" I am not prepared to say the D4 is better in low light yet. The ability to pull detail out of shadows in the D800 is just amazing to me, enough that HDR has lost a certain interest. Prior night event (a rodeo) I shot mostly the D4 due to speed, but when I did shoot the D800 it performed very well in the same light. In that same sense of comparison
Here's a D800 at ISO 6400 F2.8 with 24-70 @ 70mm.
Here's a D4 at about the same time and place, ISO 6400 F2.8 with 70-200 at about 90mm:
I don't have access to Lightroom to see how I treated each, they are both 9meg crops so the D800 is more heavily cropped, again putting them pixel to pixel which shows the D4 at its best in comparison.
At reasonable viewing sizes which is "best"? I'm not sure I could choose. At 1:1 the D4 looks substantially cleaner (lightroom's role in that I cannot say at present). If the D4 had been an equivilent PERCENTAGE crop, well.. I'm not sure you could tell the difference in a very large image.
I'm very happy with both for low light. But if the subject is moving fast and I want a better chance of capturing just the right moment, no comparison.
If anyone wants to browse around, these are a mixture of D800 and D4 same night. Mostly D4, but the info button will show you which is which. It was two nights, so near the middle it is really dark, then daylight again and toward the end really dark, very bad light (and very eratic mercury vapor so more bad light colors than I could figure out how to deal with in lightroom -- green became a theme!)