Nikkor G lenses have a built-in USM motor that permits auto-focusing on bodies with or without the focus motor. They also permit changing the aperture from the aperture dial on the body. Nikkor G lenses do not have an aperture dial on the lens itself.

Nikkor D lenses do not have a built-in USM motor. They can auto-focus from bodies equipped with a focus motor. Nikkor D lenses also have an aperture dial on the lens.

Do Nikkor D lenses permit aperture adjustments from the dial on the body, or does the existence of an aperture dial mean that one must use it? The G lenses presumably have some kind of motor, in addition to the focus motor, to change aperture. If adjusting the aperture of a D lens from the body is possible, does the aperture ring move? Probably not, since it would drain a lot of energy. If the aperture is controllable from the body, does this mean a D lens does have some kind of aperture motor after all?

  • \$\begingroup\$ G lenses use the same mechanical coupling to control the aperture as older lenses. All they lack is a ring outside the barrel. There is no motor in the lens that moves the blades. \$\endgroup\$
    – Blrfl
    Dec 29, 2014 at 20:25

1 Answer 1


All Nikon lenses (including D and G series) have a mechanical lever built into the lens that is moved by the camera body. No motor. The aperture ring is typically left locked at the highest aperture setting (say f/22) and aperture controlled by the dial on the body.

Here is the lever on my 50mm 1.4G:

enter image description here

As @Blrfl said, the only difference between D and G is that the G lacks the external ring for manually changing aperture, which is rarely needed on a modern body anyway. The internals are the same for aperture.

  • \$\begingroup\$ Very interesting.. I see that the play (the distance moved by the lever) is very short. This hints that the aperture ring on a D-type lens does not move when the lever is manipulated by the body (since otherwise the torque required would be substantial). Is that the case? \$\endgroup\$
    – Calaf
    Dec 31, 2014 at 22:41
  • \$\begingroup\$ @Calaf No, the aperture ring remains fixed, only the aperture leaves are moved. \$\endgroup\$
    – MikeW
    Jan 1, 2015 at 1:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.