HDMI remote camera control protocol

How does the ATEM control camera settings over HDMI? Does it use the HDMI ethernet, or rs232 or something else entirely?

We just picked up an ATEM extreme iso and 3 BMPCC 6K G2s and I did a quick test and when I connect directly with HDMI, I can control the shutter and lens focus from the ATEM. But the HDMI extenders I got, which are "HDMI 2.0 Compliant" don't pass the control or tally light, etc.

If I got new HDMI extenders that have the CEC passthrough, is that enough to give me this control, or would I be spending the extra money and be stuck in the same spot?

Anyone have any experience with going this route?

Thank you!

f I got new HDMI extenders that have the CEC passthrough, is that enough to give me this control, or would I be spending the extra money and be stuck in the same spot?

Might work, might not, CEC passthrough doesn't guarantee compatibility, most folks are using the fiber HDMI cables for long HDMI runs. There's more info about it in the Live Production subforum. Search HDMI fiber for some reading material.

Good Luck

Thank you, I'll check it out!