Hi SkynetTX.
Not sure why you want to focus the lens off the camera, but it should not be a problem with the Canon lens for which this is a direct competitor, the 24-70 f2.8L II.
No STM or Nano USM Motors in this one.
Copied from the canon page.
"Precision autofocus, with control
A ring-type ultrasonic autofocus motor means that you can focus quickly, near-silently and with precision. It also provides override manual focus allowing you to stay in control. This helps you to adjust the focus accurately to ensure it is exactly where you want it to be for the most creative control."
From the specs page.
AF actuator Ring USM¹
Footnotes
AF actuator - ¹ Full time Manual focus
Hope this helps.
Cheers, Graham.
SkynetTX said:
neuroanatomist said:
Do those motors not autofocus? Or how, exactly, do you define useless?
No support for Full-Time Manual focusing that – in my opinion – means that I can rotate the focusing ring even if the lens is not attached to the camera.