Nikon D7100 review
23.5x15.6mm 24.0-megapixel sensor, 5.8x zoom (27-157mm equivalent), 1.2kg
The Nikon D7100 is the company's latest digital SLR for enthusiasts and semi-professional photographers. It's an update to the Nikon D7000, which has been a firm favourite at the Expert Reviews office since its launch back in 2010.
Much of the D7000's success stems from its ergonomics and controls, so it's good to see that very little has changed here. The large optical viewfinder, substantial 950-shot battery life, passive LCD screen for displaying settings and dual command dials distinguish it from cheaper SLRs, such the Nikon D5200. Meanwhile, the twin SDXC card slots and weather-sealed magnesium alloy body are unusual to find even at this price.
We really like the control system, with dedicated buttons for a wide range of functions including ISO speed, white balance, metering, autofocus mode and bracketing. These are adjusted by holding down the button and turning the command dials. The dual dials are used to good effect, such as adjusting the ISO speed with the rear dial and toggling Auto ISO with the front dial. Many of these buttons are accessed with the left hand, leaving the right hand in charge of the dials; it's this two-handed operation that we find extremely fast and intuitive. The main menu isn't the quickest to navigate, but with so many physical controls, there's very little need to visit it. Exposure mode and drive mode have dedicated dials, both of which have locks to avoid accidental use.
External changes compared to the D7000 are hard to spot, but there are some welcome tweaks. The 3.2in screen is a little bigger and its resolution has increased to 1.2 million dots, with white pixels joining the usual red, green and blue for increased brightness. There's a new button marked i, which gives quick access to an additional ten functions via the screen, such as HDR shooting, colour presets, noise reduction strength and the function of the two customisable buttons on the front of the camera.
The live view, video record and autofocus point lock buttons have been rearranged to a more logical layout, and there's a lever to toggle the live view mode between photo and video duties. This sets the aspect ratio to 3:2 or 16:9 (for photos and videos respectively) and also makes it clear that videos can't use shutter speeds slower than the selected frame rate, or that the aperture can't be adjusted while recording. These restrictions weren't so obvious on the D7000.
There's no discernible improvement to the live view mode, though. Autofocus becomes frustratingly slow in this mode, sending shot-to-shot times plummeting from 0.45 to 4.8 seconds in our tests. Live view is still useful for fine-tuning manual focus, and the D7100 reveals sharper detail than the D5200 when magnifying the live view image.
The majority of changes compared to the D7000 are inside the camera. The sensor's resolution is up from 16 to 24-megapixels, and it dispenses with an optical low-pass filter to maximise detail levels (more on this later). The autofocus sensor now has 51 points, including 15 cross-type points for increased sensitivity. The D7000 already lead the way at this price with its 39 points, but we're more than happy to have even more. The dense cluster of points covers most of the frame, and makes it easy to focus precisely on the subject rather than have to line the subject up with an autofocus point.
More points should also improve the accuracy of the 3D tracking focus mode. We didn't have the D7000 to compare it with but the D7100 did a fine job of tracking subjects as they moved nearer, further and around the frame, with more than half the shots in sharp focus.
Continuous shooting performance is quoted as 6fps – the same as the D7000. However, the higher resolution has taken its toll on the camera's endurance. With a fast SDHC card, the D7000 kept going at 6fps for 100 shots. With the D7100, it only managed 18 frames at 5.9fps before it slowed to 3.4fps. That's not a terrible result, though, and will probably suffice in most situations. There's also a 1.3x crop mode, which uses a smaller central area of the frame to give 15.3-megapixel photos at 7fps (6.8fps in our tests). That lasted for 24 frames before slowing to 4.2fps.
Continuous raw performance was much shorter-lived, starting at 4.9fps and slowing to 1.4fps after just five frames (the D7000 lasted for ten). We were able to raise the initial speed back up to 5.8fps by switching from 14- to 12-bit raw formats, but it still only lasted for five frames – less than a second – before slowing dramatically. The 7fps, 1.3x crop mode managed nine frames before slowing.
Continuous JPEG shooting also took a big hit when Auto distortion control (for counteracting lens distortion) was enabled, slowing to 1.9fps after seven frames. The bottom line is that sustained fast performance is possible, but only if you're willing to forego raw mode and distortion correction, and possibly lower the resolution. These are choices we'd prefer not to have to make on a £1,000 camera.
The video mode has some useful upgrades. There's a headphone out to complement the microphone input, plus a stereo rather than mono built-in microphone. The frame rate is no longer fixed at 24fps, with a choice of 24p, 25p and 30p, plus 50i and 60i in 1.3x crop mode. It's a bit daft that the crop mode must be set elsewhere first, or else the 50i and 60i options are greyed out – why not just perform the crop automatically? There should be more than enough detail from the sensor to produce sharp 1080p video from this 1.3x crop area, but videos in this mode weren't as detailed as when using the full sensor area.
Otherwise, video quality was excellent, and we were pleasantly surprised to find very little evidence of moiré interference – something that previous Nikon SLRs' video modes have all suffered from. Clumsy video autofocus remains unresolved, though. It must be updated on demand and spoiled the soundtrack when using the internal microphone. Shutter- and aperture-priority modes aren't available for video, but manual exposure is, making this a solid choice for serious video work.