STANDOUT FEATURE: 24.1 megapixels with no low-pass filter for maximum detail.
Estimated Street Price: $1,199 (body only)
The new 24.1-megapixel DX (APS-C) CMOS sensor has no OLPF (optical low-pass filter). The OLPF slightly blurs the image at the pixel level to minimize moiré and artifacts inherent in the Bayer-filter sensor system used in all current DSLRs except Sigma's, but the high pixel density on the D7100's DX sensor combines with diffraction to make the OLPF unnecessary. Nikon's D800E was the first Bayer DSLR to do away with the OLPF (actually, the filter is still there on that camera, but its effects have been cancelled); the Pentax K-5 IIs and D7100 are the second and third. Bottom line: excellent resolution. Nikon's EXPEED 3 processing delivers a normal ISO range of 100-6400, expandable to 25,600, and 6 fps shooting (7 fps in 1.3x crop mode).
A new AF system features 51 AF points (vs. 39 for the D7000), including 15 cross-types. Using the AF algorithms of the flagship pro D4 DSLR, the system should handle moving subjects extremely well. Like the D4, the D7100's AF system can function in light levels as dim as EV -2, and with lens/teleconverter combinations as slow as f/8. When the D7100's new 1.3x DX crop mode is activated, the 51 AF points pretty much cover the entire image area. In 1.3x DX crop mode, the camera crops in on the full DX image (which is already "cropped" 1.5x compared to a full-frame image), for a total effect of near 2x crop compared to full-frame. A 300mm lens on the D7100 in 1.3x DX crop mode frames like a 600mm lens on a full-frame camera, while still providing 15.4-megapixel images—great for wildlife photographers.
The D7100 offers better video capabilities than the D7000: 1080 full HD at 60i, 30p and 24p, and 720 HD at 60p, with stereo sound via a built-in or an optional external microphone, and full-time contrast-based AF if you want it. (1080/60i movies are shot in 1.3x crop mode.)