The D7100 is very similar in size, layout and functionality to the D7000, but now incorporates the operational changes to movie recording and live view activation that have been implemented across Nikon's current generation of enthusiast-oriented DSLRs. As such, both D7000 users looking to upgrade, as well as D600/800 owners looking for a second body will find most of the key controls right where they'd expect them.
There are exceptions, though. D7000 upgraders will have to adjust to the position of the magnification buttons being swapped, with the plus (zoom in) button now being above the minus (zoom out) button. And D800 owners used to a top-mounted ISO button will have to get used to activating that option via a rear button on the D7100, where it is more difficult to find by touch.
The D7100 features a solidly-built magnesium alloy body that offers moisture and dust resistance. The functionality of both front and rear dials can be adjusted via the extensive custom menu options familiar to Nikon DSLR owners. And, like the full frame D600 and D800 models, the camera's mode dial is locked to prevent accidental operation. The ports on the D7100 are arranged behind three hinged doors. The separation means you only have to leave a narrow door open if you choose to attach the WU-1a Wi-Fi module.
A seemingly small feature, but one we're very pleased to see on the D7100, is the ability to customise the rear 'OK' button to be a one-click magnifier in playback mode. This is a huge time-saver that we've come to really appreciate when reviewing images taken with the D800 and D4, yet one that is frustratingly absent from the D600.
Compared to Canon EOS 7D
The Nikon D7100 is the company's flagship APS-C DSLR and thus competes most directly against Canon's admittedly long-in-the-tooth EOS 7D. The D7100 is a decidedly smaller, lighter camera, that offers higher resolution (24MP vs 18MP) but a slower maximum shooting speed.
The D7100 is shorter than the EOS 7D, due largely to a more compact viewfinder housing. The D7100 has a lockable mode dial and a front dial that sits in front of, rather than behind the shutter release.
Both cameras offer a wealth of controls on the rear of their bodies and offer 100% scene coverage with their viewfinders. The D7100 has a slightly larger rear LCD of 3.2 vs. 3 inches.
The top view of these cameras neatly sums up operational differences between Nikon and Canon. On the D7100, drive modes are accessed on the left of the camera, directly underneath the mode dial, while the EOS 7D offers Canon's familiar row of buttons (including drive mode) located on the right of the camera just in front of the top LCD. The D7100 features stereo microphones which sit just forward of the hotshoe.
Compared to Pentax K-5 IIs
The D7100 and the Pentax K-5 IIs are currently the only Bayer-pattern APS-C DSLRs to forgo an anti-aliasing filter. The D7100 has a higher resolution of 24 vs 16MP but both cameras offer weather and dust resistant sealing.
The D7100 is a bigger camera than the Pentax K-5 IIs in every dimension, yet due to its lightweight magnesium alloy and polycarbonate construction weighs essentially the same amount. Both cameras feature an integrated shutter release/power switch combination, IR receivers and AF assist illumination.
From the rear it's easy to see the operational consequences of a smaller DSLR form factor. The D7100 features larger buttons and a control layout that spans both sides of the camera, while the K-5 IIs places virtually all of its controls to the right of its smaller LCD screen.
Both cameras feature lockable mode dials, a top LCD display, built-in flashes and an exposure compensation dial behind the shutter release. The K-5 IIs adds a dedicated ISO button while Nikon opts for movie record and metering mode controls.