SEL50M28 FE Macro lens focus oddities

[holmes4]

I recently received the Sony SEL50M28 50mm Macro lens. As a macro lens, it's fine (though in my opinion 50mm is too short for a macro lens), but as a normal lens it leaves a lot to be desired (especially the agonizingly slow autofocus.)

 

What puzzled me greatly was how autofocus did or did not work on my A7ii. First, I have the camera set up for back-button focus, so it doesn't focus until I press the button on the camera back. The 50M28 ignores this and autofocuses all the time, even without pressing the shutter release. There is also a button on the lens for "focus lock" that supposedly stops the autofocus, but it had no effect for me. 

 

I would typically use this lens in manual focus mode only, but I wonder if anyone else has had similar experiences with this lens. The three Sony/Zeiss lenses I have behave normally with BBF.

[Guest all8]

Do you have Pre-AF enabled in the menus?

[holmes4]

I don't see anything called PreAF - where would that be?

[Username]

I don't see anything called PreAF - where would that be?

  

I think it's called "Eye Start" or something like that. 

[Lescatalpas]

I think it's called "Eye Start" or something like that. 

No, it's called Pre-AF, and it's on page 3 of the custom settings part of the menu (the gear icon) on the A7ii

[holmes4]

Pre-AF was indeed the culprit - I wonder why that didn't affect my Zeiss lenses? Thanks.