FTZ adapter firmware update broke autofocus on 18-35mm D?

Started 4 months ago | Questions thread
BasilG Veteran Member • Posts: 9,421
Re: FTZ adapter firmware update broke autofocus on 18-35mm D?

mobydick wrote:

I guess that's my point. "D" is not informative:

There are lenses labelled "D" without internal motors.
There are lenses labelled "D" with internal motors.
There are lenses without D designation without internal motors (both pre-D and G).
There are lenses without D designation with internal motors.

The D designation, whether you use the "AF-D" short hand or not, does not provide any information on the way in which focus is achieved.

Ok, after doing some additional small research on my own I am convinced by your argument.

Good to hear.

E.g., the 300/2.8 lens exists as AF-S lens with explicit D designation and also as AF-I lens with explicit D designation.

Thinking further: "G" seems to subsume "D", and "E" subsumes "G" (and "nothing" is before "D").

Not sure about the technical details, but G is pretty much the same as D, except that the aperture ring has been removed (aperture setting now controlled by the camera but still using mechanical coupling), while E uses an entirely different way to control the aperture (electronic rather than mechanical).

This naming scheme is orthogonal to the AF naming scheme: AF, AF-I, AF-S, AF-P

Indeed. Orthogonal may be the right way to describe it.

Some combinations of both factors exist, many don't:

  • AF lenses (screw-drive) exist as "nothing", D and G.
  • AF-I lenses exist as D.
  • AF-S lenses exist as D, G, E.
  • AF-P lenses exist as G.

Have I missed anything?

Not a lot: AF-P lenses also exist with E-type aperture (e.g. the 70-300 FX zoom).

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