Nikon DX Lenses Overview
Intro 2003 Autofocus for DX Nikon Digital Cameras ie with 24mm sized sensors.
Nikon DX Lenses, introduced in 2003 are designd for the 24mm sensor sized DX Digital Cameras.
All DX lenses have DX written on their body. Nearly All DX lenses are also AF-S with the remainder being AF.
Nikon Digital Cameras are divided into two types. Those with 36mm image sensors (ie same as 35mm film cameras) and those with 24mm sensors.
The full frame 36mm type, are used by the top of the range cameras. Of these, both cameras and sensors are often called FX. Full frame cameras include D3, D3X and D700,
The small frame 24mm type, are used by all the remaining cameras. The cameras and sensors are often called DX as well as the lens. The 24mm sensor is also know as APS type or 1.8".
The focal length of a DX lense is given inrespect to its optical chararacteristics and a 100mm DX lens has the same focal length effect as non-DX 100mm lens. If, however, you put a 100mm lens on a DX camera (sensor size 24mm), due to the small area cropping effect, the effective focal length is increased by about 50% and so effectively becomes 150mm. It is not the lense, but the camera's sensor size which determines this. Becasue DX lenses are almost invariably used with DX cameras, their focal length, for any given lens, is almost invariabley effectivly 50% greater than the equivalent film camera of FX digital camera.
Because the DX sensor is smaller, the size of their glass can be smaller with the advantage of it being lighter and less expensive. The disavantage is that a DX sensor, having less pixels, will not have the resolution of the full frame FX cameras. Also, the DX lense produces a small image which is not large enough to cover all of a full frame FX 36mm sensor in an FX camera.
It is possbile to use a DX lense on an FX digital camera which should auto compensate for the smaller projection. (I.e. avoid the issue of the non-exposed corners). Conversely, there is no problem on fitting a modern AF-s lense on the DX cameras. The AF lenses, however, have no internal focus motor, will work on all digital camera except D40, D40x and D60 which have no lens focus motor drive in the camera.
All Nikon Digital SLRs work with the autofocusing aspect of Nikon DX lenses.
All Nikon Digital SLRs metering works with all DX lenses.
Digital Vari Program, P (program), S (shutter priority), A (Aperture priority) M (Manual).
All Nikon Digital SLRs Modes work with All DX lenses.
All Nikon DX lenses have DX written on the lense after their AF-S or AF marking.