D would be a lens for full frame (FX) cameras. D800, d700, etc
DX would be a lens meant for a cropped sensor body. D90, d300, etc
You can use d glass on a crop body but it has to have the motor in the body to use AF. D7000 iirc this not an issue. D40...no motor in body so no AF for the other end.
Edit: If you use full frame glass on a crop body you jsut get a different perspecitve as it were. easy example. Crop sensor math go by 1.5 to estiamte how it will look.
A 50 1.4 D on a crop body will be more of a 75mm lens.
A DX lens is specifically for DX 'crop' sensor cameras. They will mount on FX cameras, but you will usually get severe vignetting. Some DX zoom lenses will produce an image circle large enough to fill a FX sensor.
The 'D' designation means that the lens will communicate distance information to the camera body. All current autofocus lenses are 'D' lenses.
'AF' lenses require a motor in the camera body to drive the autofocus screw on the lens. The current consumer cameras do not have the motor, thus are unable to autofocus with 'AF' lenses.
'AF-S' and 'AF-I' lenses have the autofocus motor built into the lens and is controlled by the camera body through the contacts.
beavo451 wrote:
The 'D' and the 'DX' are not related at all.
A DX lens is specifically for DX 'crop' sensor cameras. They will mount on FX cameras, but you will usually get severe vignetting. Some DX zoom lenses will produce an image circle large enough to fill a FX sensor.
The 'D' designation means that the lens will communicate distance information to the camera body. All current autofocus lenses are 'D' lenses.
'AF' lenses require a motor in the camera body to drive the autofocus screw on the lens. The current consumer cameras do not have the motor, thus are unable to autofocus with 'AF' lenses.
'AF-S' and 'AF-I' lenses have the autofocus motor built into the lens and is controlled by the camera body through the contacts.
'G' lenses do not have aperture control rings....Show more →
beavo451 wrote:
The 'D' and the 'DX' are not related at all.
A DX lens is specifically for DX 'crop' sensor cameras. They will mount on FX cameras, but you will usually get severe vignetting. Some DX zoom lenses will produce an image circle large enough to fill a FX sensor.
The 'D' designation means that the lens will communicate distance information to the camera body. All current autofocus lenses are 'D' lenses.
'AF' lenses require a motor in the camera body to drive the autofocus screw on the lens. The current consumer cameras do not have the motor, thus are unable to autofocus with 'AF' lenses.
'AF-S' and 'AF-I' lenses have the autofocus motor built into the lens and is controlled by the camera body through the contacts.
'G' lenses do not have aperture control rings....Show more →
Exactly!
And to add, a lens can either have a D or a G designation. Both will communicate distance information to the camera but a G lens won't have the aperture ring and therefore aperture is controlled electronically through the camera.
