Although the new Nikon D7100 looks fairly similar to its predecessor (the popular Nikon D7000), Nikon has made some significant changes under the hood that belie the surface similarity. The D7100 not only includes a higher-resolution CMOS sensor, but even more significantly, the company chose to use a sensor without an anti-alias filter for the first time on a non-full-frame DSLR. While this should enable better sharpness and resolution, it may also result in more moiré patterns in some images.
Back when Nikon first introduced the D7000 two and a half years ago, the only real competition in its midrange DSLR class was from Canon. In fact, the D7000 carved out a new spot in the Nikon DSLR lineup between the D90 and the D300s to compete directly with the Canon EOS 60D. The new Nikon D7100 (priced at $1,200) takes the D7000’s place as Nikon’s flagship APS-C sensor camera, but enters a market that has a lot more contenders. Besides the Canon EOS 60D, which has since dropped in price to $900, recent DSLRs that compete directly with the D7100 include the Sony SLT Alpha 77 ($1,100) and the Pentax K-5 II and K-5 IIs ($1,100 and $1,200, respectively).
Like the Pentax K-5 IIs (and big brother Nikon D800E), the Nikon D7100 eschews an anti-aliasing filter – or optical low pass filter (OLPF) – to gain sharpness. Though this enables photographers to achieve higher resolution and clarity for detailed images, you may end up with increased moiré effects when shooting subjects with patterns (read more about anti-aliasing filters here).
In addition to removing the anti-aliasing filter from the sensor, the D7100 bumps resolution up from the D7000’s 16.2 megapixels to 24.1 megapixels. The new camera also sports an improved autofocus system with 51 AF points (15 cross-type), in comparison to the D7000’s 39-point (9 cross-type) AF system. Other improvements include a larger and higher-resolution LCD (3.2-inch 1,229K dots in the D7100 vs. 3.0-inch 921K-dot model in the D7000), a new viewfinder that utilizes a high-contrast OLED display, and improved HD video recording capabilities (1080/30p or at 60i/50i in 1.3x crop mode). Support for an optional WiFi adapter for easy wireless file transfer and remote control (with a supported smartphone or tablet) also sets this camera apart.