>The DOF is different on FX than DX. It's not just the crop.

I don't think this is true. The DOF does change when you consider equal field of view, but this is not the best way to think about it. Keeping lens focal length constant, the DOF is the same, since DoF is a function of the lens optics and not the sensor.

Any "extra reach" you get from a DX sensor is solely due to the fact that historically, DX sensors had smaller pixel pitch than their FX counterparts. Now, the pixel pitch of the D7000 is basically identical to that of the D800. (A similar situation was seen in the past with the D3x and the D80- both had roughly 10MP in DX mode). If you're looking for reach, there is no difference between what the D7000 shoots and what this will shoot, you just get more "picture" around the edges per frame considering the larger sensor of the D800.

In your sports situation Perrone, assuming that the ISO capability of the D800 will be roughly the same or only slightly better than the D7000 (unproven, but a reasonable speculation), it is probably more versatile/effective to go with 2 D7000s and 2 lenses (one long, one wider) compared to one D800- for the same price. Or D7000 w/long lens for reach, and D3s with wider lens for closer action and better high-ISO, like you do now. I don't really see where adding a D800 in the mix really benefits the situation you described.

Now there are other factors to consider- the D7000 will potentially shoot faster than a D800 (unless you buy the battery grip for the D800, at which point the two will be equal) but the D800 may have better focusing because of the new module, but in terms of "cropping freedom", you gain nothing with a D800 that you don't already have with a D7000.

Norman

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