An upgrade to Nikon's long-running D7000 has been announced – in the form of the D7100, which keeps the 2010 camera's button layout but includes a new 24-megapixel sensor, an improved autofocus system, and a shooting crop mode that promises high-speed shooting at a similar field of view to Micro Four-Thirds.

The D7100's 24-megapixel sensor is the same resolution that debuted on the D3200, also eventually making its way to the D5200. In the D7100, it has no low-pass antialiasing filter, meaning increased fine image detail with appropriately high-resolution lenses. Paired with Nikon's EXPEED 3 imaging processor – the D7000 had an EXPEED 2 – the company claims boosted dynamic range and better images.

Where the D7000 had a 39-point autofocus system which has been adapted for use in other Nikon models like the D600, the D7100 introduces a new 51-point sensor that covers the same proportion of the image frame, meaning a larger array of focus points to use. It's more versatile than the existing system – it can be used at a maximum aperture of f/8, letting autofocus operate when using a telephoto lens paired with a teleconverter.

The new Nikon D7100 also inherits a new 3.2-inch rear LCD panel, with a 1,229K-dot resolution. The camera's viewfinder has been upgraded with a built-in OLED panel instead of the existing LCD, brighter and more detailed to show more information.

The D7100's unique feature is a 1.3x crop mode, further reducing the imaging sensor size versus a full-frame digital camera. With this crop enabled, the D7100 will 'see' the same images as a 2x crop Micro Four-Thirds camera like the ones we've seen from Panasonic and Olympus. This is designed for telephoto shooters who want to use the D7100 for long-distance photography. The 1.3x additional crop also enables high-speed shooting of 7 frames per second -- a big boost from the D7000's 5fps. Otherwise, the new camera shoots at 6fps.

The D7100 will be launched in March alongside a new WR-1 wireless transmitter. It costs £916 plus VAT for the body only, or £1,085 plus VAT with a 18-105mm lens.