Sensor: APS-C (DX) format CMOS Resolution: 24.1Mp Autofocus: 51 AF points (15 cross-type) Max shooting rate: 6fps LCD: 3.2-inch 1,229,000-dot Video resolution: 1080
• Read our full Nikon D7100 review
Compared with the D7000 that was launched some two and a half years earlier, the D7100 brought a raft of significant updates, plus a few minor enhancements. The biggest news at the time was the omission of the low-pass filter and that, whereas the full-frame D800 and D800E cameras were available with or without the filter, the D7100 simply ditched it.
Other improvements over the D7000 include a step up in autofocus from a 39-point system to 51-point AF, along with a newer generation EXPEED 3 image processor and a slightly larger, higher-res LCD screen. However, the D5300 also omits the low-pass filter, has an even newer EXPEED 4 processor, an articulated rather than fixed LCD and even boasts built-in Wi-Fi and GPS technology.
The D7100 doesn't have the articulated screen of the D5000-series Nikons, but its control layout is more sophisticated – it's aimed at enthusiast and experts who already know the adjustments they want to make.
Unless Nikon surprises us and launches a replacement for the Nikon D300s – see our Camera Rumors 2015 story – the Nikon D7100 is the top APS-C (DX format) DSLR in the Nikon range. The next step up is a full-frame model like the D610 or the D750.
Sensor: full-frame (FX) format CMOS Resolution: 24.3Mp Autofocus: 39 AF points (9 cross-type) Max shooting rate: 6fps LCD: 3-inch 920,000-dot Video resolution: 1080
• Read our full Nikon D610 review
The D610 is almost exactly the same as the D600 that it replaces, having a different shutter mechanism which is widely thought to address the problem of dirt reaching the D600's sensor.
This new shutter also allows a faster continuous shooting rate, 6fps instead of 5.5fps, and a new Continuous Quiet mode (also known as Quiet Release burst) mode.
Nikon used a similar design and control layout for the D600 and D610 as did for the D700 and D7100 APS-C body. As such, the D610 is particularly compact and light in weight for a full-frame camera and its layout will be familiar to anyone who's upgrading from a D7000 or D7100..
Interestingly, Nikon has used its 39-point autofocus system with nine cross-type points rather than its pro-spec 51-point AF system. It's called an FX rather than DX autofocus module but, even so, the AF points are all fairly close to the centre of the frame. The 6fps maximum drive rate is the same as the D7100 and just a little faster than the D810.
Sensor: full-frame (FX) format CMOS Resolution: 24.3Mp Autofocus: 51 AF points (15 cross-type) Max shooting rate: 6.5fps LCD: 3.2-inch 1.229,000-dot tilting Video resolution: 1080
• Read our full Nikon D750 review
The D750 is the next step up from the D610, and although the sensor resolution is the same, at 24 megapixels, Nikon says the sensor is 'newly developed' for this camera.
The key differences between this and the D610 are the larger, higher-resolution articulating screen, and the use of Nikon's pro-level 51-point AF system. The D750 also has a higher ISO range, beating the D610 by a full EV with a maximum sensitivity of ISO 12,800 (ISO 25,600 in expanded 'HI' mode).
Wi-Fi is built in – you need an adaptor, albeit a low-cost item, for the D610 – so you can control the D750 remotely using a smart device and Nikon's free app.
The tilting screen makes the D750 much more flexible for low-angle shots and, in particular, for shooting video. It can capture full HD at up to 50/60p and has both microphone and headphone sockets.
Sensor: full-frame (FX) format CMOS Resolution: 16.2Mp Autofocus: 39 AF points (9 cross-type) Max shooting rate: 5.5fps LCD: 3.2-inch 921,000-dot tilting Video resolution: Not supported
• Read our full Nikon Df review
The Df is Nikon's re-imagining of the classic Nikon 35mm SLR, complete with with external ISO, EV compensation and shutter speed dials, (almost) gripless 35mm SLR shape, leatherette finish and the evocative, angular Nikon pentaprism shape older photographers will remember so well.
It's not cheap, however, and it's not perfect, and if you regard technology and value for money above all else, then you're going to wonder what the fuss is all about.
The newer Fuji XT-1 has taken the old-fashioned external dial approach to its proper conclusion and has done it brilliantly; the Df stops just a little short of that and can present a slightly uneasy half-way house between old-school manual control and 21st-century automation.
The 16-megapixel full frame sensor is straight from the D4s and delivers excellent high-ISO performance and enough resolution for most needs. The continuous shooting speed is more pedestrian, though, topping out at 5.5fps.
There is no video option on the Df – and that in itself will endear it to a whole community of stills photographers who want a cameras for just one job, and one that isn't weighted down with features and controls they don't need.