What is the difference between the nikon nikkor 50mm f1.8D and the f1.8G?

Don't know witch one to get the f1.8D and the f1.8G

Both will work on any current Nikon DSLR.

The D will not AF on basic Nikons such as the D3100 or D5100 or older D40 etc as neither the camera or lens would have an AF motor.

The G is fine on the cheaper cameras as it has an AF.

The G would not work well on older Nikon film cameras such as the FM, FA, FE, F3 etc as it does not have the required manual iris ring.

The AF-D lens can be had cheaper than the G, but you would really need to have a D7000 or better.

If you are using a DX format camera and want a standard lens, then the 35mm f1.8G might be a better fit for you, the 50mm on a DX camera becomes a little telephoto.

The AF version will autofocus on all advanced amateur and professional Nikon cameras, including the D70, D80, D90, D7000, D300, etc.

It won't autofocus on entry level cameras such as the D3000, D3100, D5000, D5100, D40, and D60.

However, in an experiment Nikon added focusing capability in an entry level camera, the D50, which remains to date the only entry level camera that has a built-in focus motor.

Which one to buy depends on your camera. They are both optically good lenses.

Sorry Paul, but neither of those lenses will auto focus on the entry level stuff.

In Nikon parlance… A lens with the D designation sends focus distance information to the camera/flash, for flash exposure calculation. That is all it means.

A lens with a G designation includes the D functionality, and is an auto focus lens without an aperture ring on the lens body. The aperture is controlled by the camera body.

The 50mm f/1.8 D has an aperture ring, the G does not, other than that, they are pretty much the same.

Nikkor 50mm f1.8D is the best