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EOS C300 MKIII and autofocus problem with Cine-Servo Lenses


I'm having difficulties while using my C300 MKIII and a full set of Cine-Servo lenses. In theory - based on the user's guide - the autofocus must have worked after a quick settings ajustment, but that's not happening. My camera has a PL mount original adapter and my lenses are all PL mount versions. I need to know how to solve this problem in order to use the full capability of my C300 MKIII and my lenses to AF.



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This post would get more responses and better responses in a different part of the forum.  This would be best served in the Professional Video forum. 


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Product Expert
Product Expert

Hi rdn,

To assist you with this we will need to know what specific lens models you are using with the camera. The auto focus functions available can vary from lens model to lens model. Also since you are using a PL mount camera and lenses, do you have the 12 pin interface cable connected from the servo unit to the camera?

Yes, I have it! But still the camera doesn't enable the autofocus functions.

Product Expert
Product Expert

Greetings rdn,

We understand you state you have the 12-pin interface cable, but please provide us with the lens model you are using. You may also try clearing the camera settings. Check for any debris on the contacts for the interface cable. Please ensure that the cable is properly connected.

Greetings NatalyaP,

I have three of them. The models are:

  • Canon Cine-Servo CN7x17 KAS S/P1
  • Canon Cine-Servo CN10x25 IAS S/P1
  • Canon Cine-Servo CN20x50 IAS H/P1

All equipment is brand new. I've also tried to clearing the camera settings, but it didn't change anything. 

Product Expert
Product Expert

Greetings rdn,

Thank you for providing us with a list of the lenses you are using with your EOS C300 Mark III camera. I'm sorry but per review, the EOS C300 Mark III will not provide auto focus control from the camera when using these lenses. Please refer to page 243 of the user guide for the EOS C300 Mark III camera where it will provide a list of which lenses the camera is able to control the focus on:


Thanks for the information! 

Considering the lenses with the PL mount doens't have the autofocus function, is it possible to make a re-housing of the lenses mounts from PL to EF so it can do it? Does Canon provide this service? In an on demand situation (as mine), is there a possibility?