The Nikon path: 2. Formats

For many years, for general photography, a 35 millimeter film was used in almost every camera. Those 35mm is the width of a single frame on the film. Although there were/are different cameras using a film of smaller and larger formats, ranging from 13mm to 75mm wide, the 35mm frame became a standard and has been used for more than 100 years already. Nikon has been releasing the 35mm film cameras for years, until the digital era came. In a digital camera, there's no film, but there's a sensor onto which the light falls and gets captured, and then transformed into an image. At that time, when Nikon was switching to digital, to create a digital SLR camera with a 35mm wide sensor would cost a lot (a single piece of silicon 35mm wide still costs much) and would make the camera bulky (today with technology advancements that's no longer the case). Therefore, Nikon decided to make the sensor size smaller, 1.5 times smaller, and called that format: DX. The 1.5x became known as a "crop factor", meaning the standard 35mm film was cropped and became a 24mm wide sensor (it is in fact a 24 x 16 mm sensor). If you take a 35mm camera and a Nikon DX camera and use exactly the same lens on both, then with a 35mm camera you will be able to capture more in terms of the visible image, that is, more will fit into the frame both horizontally and vertically. So, the DX sensors will only capture a smaller part (a subset) of an image that otherwise a standard 35mm camera would capture. Canon went with their own crop factor, and used 1.6x instead of 1.5x, which means that most Canon dSLR cameras crop even more of the visible image, resulting in slightly smaller captured area. Here's an example:


Using exactly the same lens, the full picture above is what a 35mm camera would capture, the image inside the green outline is what a Nikon DX camera would and the image inside the blue outline is Canon's final result (for the sake of completeness, there are several Canon models that use a 1.3x crop factor, but the majority uses 1.6x).

As time went by, with advances in technology, in 2007 Nikon released its first what is called a "full frame" digital camera, meaning that the sensor size was the size of a standard 35mm camera (actually, the sensor is 36 x 24 mm). Now, in addition to a DX series, Nikon introduced a series of full-frame cameras, which it called: FX. Currently, all Nikon dSLRs by their sensor size can be categorizes like so:

Beginner: DX
Advanced: DX
Pro: FX

So far, there are only 3 full-frame models in Nikon's lineup: D3 (2007), D700 (2008), and D3X (2008), with the D700 being the most compact and affordable of all three (around $3000 body only). In general, as of today, only full-frame dSLR cameras are considered professional, with anything else being an amateur camera.