DX and FX both refer to the size of the images sensor used within the camera. Here, we find out more about both the DX and FX formats.
The DX format sensor is the smaller sensor out of the two, at 24x16mm in size. DX format bodies include the D3300 and D5300. As DX cameras have smaller sensors, it is possible to build smaller, lighter camera bodies around them. Lenses specifically for DX format bodies have been created by Nikon, which are optimally designed for use with DX cameras. DX format cameras cover a smaller portion of the image projected by the lens, and so a 1.5x crop factor is introduced. This means that the smaller sensor crops the image when compared to an image from a 35mm film frame. FX lenses can be used on a DX camera as the image circle is larger than needed and so makes no difference to the overall image.
The FX format sensor is larger, at 36x24mm. This is approximately the same size as 35mm film. FX format cameras include the new Nikon D4s, and its predecessor the D4. An FX sensor has more light gathering area and so images produced with this format tend to have less noise and higher sensitivity. The FX format doesn't have a crop factor, either. DX lenses can be used on an FX camera, however the camera will automatically engage the built in DX crop mode, recording an image from the centre section of the sensor only.
To find out more about the variety of Nikon DSLRs on offer, take a look at the Nikon UK website.