I have a difficult decision to make between these two cameras for this specific purpose. I'm shooting with a 500 f4 AF-S & TC-14E with fill flash (SB-800, quantum battery, flash extender) in aperture priority mode, high speed sync, std. TTL. Speed and buffer don't count as the recycle time for the flash sets the pace. Resolution - in terms of file size for printing - is off the table as well as I would shoot the D800E in 1.2x crop mode. Cost is not really relevant, as I can easily afford either.
My assumption is that I would shoot the D7100 much as I do my D300: largely ISO 400 (and above), f7.1. The D800E with the 1.2x crop I would shoot at f9, ISO 640 and above. This should establish equivalence. I'm assuming that the D800E will have about a 1-1/3 stop advantage in DR and noise at a given ISO in the relevant range - up to 1600 on the D7100 and 2500 on the D800.
My take on the advantages/disadvantages of the cameras is this:
D800E advantages:
My assumption is that I would shoot the D7100 much as I do my D300: largely ISO 400 (and above), f7.1. The D800E with the 1.2x crop I would shoot at f9, ISO 640 and above. This should establish equivalence. I'm assuming that the D800E will have about a 1-1/3 stop advantage in DR and noise at a given ISO in the relevant range - up to 1600 on the D7100 and 2500 on the D800.
My take on the advantages/disadvantages of the cameras is this:
D800E advantages:
- Pro body: more rugged, more familiar controls (coming from D2X, D300/s).
- Proven technology: thoroughly tested at this point.
- Reach: 1050mm vs. 840mm (35mm equivalent).
- Viewfinder: slightly more magnification.

