Lens with motors vs cameras with motors

[XKAES]

I have a simple question.

Will AF lenses that have internal motors for focusing work normally with cameras that have internal motors for focusing -- that is, without adapters, work-arounds, manual-focusing-only, etc.

Edited July 14, 2022 by XKAES

[Pieter]

As far as I know, all of the latest A-mount bodies feature both a screw drive mechanism as well as electronic coupling to autofocus SSM / SAM lenses. So yes, these cameras - with internal focus motors - can focus lenses with internal focus motors. The screw drive mechanism is just not engaged.

[XKAES]

I guess I should have asked

"Will AF lenses that have internal motors for focusing work normally with cameras that ONLY have internal motors for focusing -- that is, without adapters, work-arounds, manual-focusing-only, etc."

I assume that cameras designed to focus lenses with the camera motor will not work with lenses that have a focusing motor in the lens.

I recently read that Nikon stared out with camera motors doing the focusing, and now only produce lenses with motors in the lens for the focusing -- so the new lenses won't work with the old cameras -- even though the lenses fit.

Edited July 14, 2022 by XKAES

[tadwil]

Brands that care about backward compatibility would make provisions to be able to focus older AF lenses without motors with a screw drive system.  Nikon and Pentax did that, though Nikon only did so in a limited way.  Putting motors in the lenses is a lot more sensible.  It's much faster to acquire focus and much quieter than a screw driven AF lens.  My Tamron 90/2.8 AF macro lens on a Pentax body can sound like a traffic jam if I don't set the focus limiter and if I happen to be trying to focus on a subject with little contrast in poor lighting condition.  The lens racks back and forth, trying to find focus, sometimes without success - need a modelling light bright enough to acquire focus.

Canon abandoned the FD mount and built EF mount bodies that has no motor built-in, instead it only had contacts so the body can communicate with the lens  This is basically the standard for all modern AF lenses with built-in motor for almost all brands.  If your camera body has a screw drive coupler and the contact pins built-in, the chances are very good you can use both the older AF lenses without motor and the newer modern lenses with built-in AF motor.

[Pieter]

I guess @XKAES's question is whether older bodies dating from the screw-drive era are forwards compatible with later lenses with built in AF motors.

I think the answer to your question can be found here:

https://en.m.wikipedia.org/wiki/Minolta_A-mount_system

The camera needs to have 8 electronic contact points to be able to communicate AF instructions to the lens. Older Minolta bodies only have 5 contact points on the mount and can therefore not focus AF-lenses with built-in focussing motors.

[XKAES]

We're getting closer, but I'm not talking about Minolta five-pin AF cameras.  I'm talking about eight-pin, a-mount cameras that focus the lens with a motor in the camera.

If you slap on any eight-pin, a-mount lens (Sony or otherwise) that has a focusing motor IN THE LENS, will the camera be able to auto-focus that lens?

I assume that these lenses do not have a mechanical connection to the auto-focusing motor in the camera.  Maybe I'm right, maybe I'm wrong.  Maybe it doesn't make a difference.  Maybe it does.

[michelb]

In A-Mount, Minolta branded were mostly lenses that were screw-driven through a motor in camera. Motorised AF lenses were called SSM( Super Sonic Motor). And there were only 2 of those ( AF 70-200 F 2.8 APO(D) SSM and 300mm F 2.8 APO (D) SSM.

Sony also had a line of motorized lenses called SAM but these were more of entry-level whereas higher end lenses also used the SSM designation.

 

All A-Mount Minolta film cameras introduced after 2001 have the capability of using SSM and SAM lenses ( Maxxum 7, Maxxum 5 and a few others but most were entry level with little popularity among advanced amateurs). Maxxum 9 could get updated to add this possibility but they can not be updated anymore. Using a SAM or SSM lens on bodies made prior to 2001, AF will just not operate. 

All A-Mount Minolta and Sony digital bodies have the capability of using SSM and SAM lenses. 

All NEX and Alpha mirrorless can use the E-Mount lenses that all have internal focusing motors. To drive A-Mount with screw driven AF, they require the right adapter that includes a motor to allow AF (LA-EA2, LA-EA4 or LA-EA5 with this last model on select bodies only).

If the lens designation does not mention either SSM or SAM, it is a screw-driven (body driven) lens.

Edited July 15, 2022 by michelb

[XKAES]

I guess I'm still not getting through.  I'm not talking about Minolta cameras.  OK?

I'm talking about SONY a-mount cameras that have a focusing motor in the camera body.

Will these cameras auto-focus a-mount lenses (SONY or NOT) that have an auto-focus motor in the lens?

Seems like a simple question to me, but apparently not.

[michelb]

All Sony A Mount bodies have a motor to drive AF in lenses AND the capability to drive SAM and SSM lenses that have the AF motor in the lens.

As i mentioned in my post above. This was introduced by Minolta in 2001 in their film bodies, along the introduction of the Maxxum/Dynax/Alpha 7. It has continued until the end of the A-Mount. There are  a lot more lenses out there with non-motorized in-lens AF than there are SSM or SAM lenses.

[XKAES]

Thanks.  I read this on-line and it make me ask the question -- the "unlikely" made me wonder!

"Minolta A-mount camera bodies released before 2000 do not support SSM and you’d be left with manual focus only, but that’s unlikely to be a problem for most Sony shooters."

[alasdairmac]

On 7/15/2022 at 1:52 PM, XKAES said:

I guess I'm still not getting through.  I'm not talking about Minolta cameras.  OK?

I'm talking about SONY a-mount cameras that have a focusing motor in the camera body.

Will these cameras auto-focus a-mount lenses (SONY or NOT) that have an auto-focus motor in the lens?

Seems like a simple question to me, but apparently not.

Short answer: YES. I started with the original A100, and have since owned an A200,A55 and A77ii before buying my present A7iii and ALL of them autofocussed perfectly with in-lens focus drive motors.

Edited August 1, 2022 by alasdairmac

[XKAES]

Thanks.