I ordered a tilt adapter from EF (Canon EOS) to NEX (Sony e-mount).

The adapter doesn't have an electronic interface is there any way to manipulate the aperture?

All other adapters I use have either a mechanical ring or the lenses don't have any electionics (manual aperture ring).


1 Answer 1


Canon EF lenses have electronically controlled apertures that cannot be controlled without power. It may be left wide open or stopped down when detached from a camera.

There is a hack you can use to set the aperture to a desired F-stop.

  • Attach the lens to a camera or adapter that is able to control the aperture.
  • If you want the aperture wide open, you can just detach the lens while the camera is turned on. The aperture should also be left wide open when the camera is simply turned off.
  • If you want the aperture to be stopped down to a particular F-stop:

    • Set the aperture on the camera.

    • Press the depth-of-field preview button.

    • Detach the lens while the aperture is stopped down to the desired F-stop.

You can also adapt manual lenses from some other mounts to EF mount. This is what I would prefer.

  • M42, T2 screw mounts
  • Nikon F
  • Olympus OM
  • Pentax PK
  • Tamron Adaptall
  • \$\begingroup\$ That the aperture stays at the selected f-stop when detached (without powering off first). \$\endgroup\$
    – stacker
    Feb 2, 2019 at 20:40
  • 1
    \$\begingroup\$ @stacker You must have the DoF button pressed. A shutter half-press does not normally stop down an EF lens on Canon cameras. \$\endgroup\$
    – Michael C
    Feb 3, 2019 at 14:59
  • \$\begingroup\$ @xiota I've never seen a half press stop down the aperture. Other than shooting video (obviously in LV) with 'exposure simulation' enabled, I've never seen an EOS camera stop down until actually recording a still or video clip. I'd like to know what camera, shooting mode (VF or LV), settings, etc. you use to reproduce this behavior. \$\endgroup\$
    – Michael C
    Feb 3, 2019 at 23:57
  • \$\begingroup\$ @MichaelC Camera had ML installed previously. ML leaves traces of itself behind. Removed statement in answer about shutter half press because likely associated with custom firmware and not relevant to normal use. \$\endgroup\$
    – xiota
    Feb 4, 2019 at 0:35

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