I have a teleconverter (Bower MC 2x C/AFI) which has pins to connect the lens electronics to the camera body. It works well with my autofocus lenses. If I try to use the converter with a manual-focus lens, like the Samyang 135mm F2.0, I always get the following error:

Err 01
Communication between the camera and lens is faulty. Clean the lens contacts.

The camera body is a Canon 90D or 550D (same behavior on both). The lens contacts are clean. The picture is actually taken successfully but the error prevents me from taking more pictures.


  1. Is there any way to avoid this error?
  2. Are there any teleconverters specifically for manual-focus lenses? I cannot seem to find any online.
  • \$\begingroup\$ What exposure mode are you using? An Auto, semi-auto, or manual (without Auto ISO) mode? \$\endgroup\$
    – Michael C
    Sep 29, 2020 at 3:03
  • \$\begingroup\$ Exposure mode does not seem to make a difference. The camera does take a picture so I do not think this is the issue. The error happens after taking the picture. \$\endgroup\$
    – tharter
    Sep 29, 2020 at 18:02

1 Answer 1


The classic solution is to place a piece of tape over some or all of the teleconverter's contacts between the lens and TC (three left pins on the TC side facing the lens) or between the camera and TC (all of them). Gaffer tape works well because it leaves no residue when removed.

Of course this assumes your camera will allow you to take a photo without it detecting that a lens is attached. The 90D does this. I'm not sure about the Rebel T2i/550D.

  • You'll need to be shooting in Manual exposure mode.
  • Be sure that you've also manually selected a specific ISO setting, rather than leaving the ISO set to 'Auto.'
  • You may also need to select an option in the camera's menu to allow an image to be captured without the camera confirming focus first.
  • You may also need to select an option in the camera's menu to allow an image to be captured with no lens detected by the camera.
  • With some Canon cameras you may also need to set AFMA to "disable" when using older TC's.
  • \$\begingroup\$ Yes, taping the contacts is also my suggestion and yes the T2i will let you shoot w/out the lens. There is a setting in the menu. \$\endgroup\$
    – user85781
    Sep 29, 2020 at 5:34
  • \$\begingroup\$ The tape made it work even with automatic exposure and ISO setting (just like if the lens is connected directly). I was hoping for some setting I did not know about, but this will do the trick. \$\endgroup\$
    – tharter
    Sep 29, 2020 at 17:59
  • \$\begingroup\$ @tharter If you tape only the three left pins between the TC and lens sometimes that works and sometimes not. If one has to tape over all of the pins between the TC and camera body, then manual exposure and release without lens,etc. must be followed. \$\endgroup\$
    – Michael C
    Sep 29, 2020 at 18:42

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