Camera Control From ATEM Mini Pro Not Working

Hi, because of a longer distance, I’m connecting my BMD Pocket 4K camera from it’s HDMI out to a BMD Micro Convertor HDMI to SDI, from there running SDI cable to a BMD Micro Convertor SDI to HDMI, and from there to the HDMI in on my ATEM Mini Pro.

The camera image comes through but with this setup I’m unable to control the camera from the ATEM Mini Pro.

Is this because once you get those convertors in the signal chain, communication between the ATEM and the camera stops working?

Or is it possibly because the SDI cable that I’m using is 20 years old and doesn’t allow 2 way communication?

thanks for your help on this, best, Peter

Unfortunately SDI is a one-way protocol and it won't do 2-way comms that's needed for the BMPCC cameras.

It's also an issue of the HDMI camera control protocol being proprietary and non-standard. Even with dual SDI cables (the way the higher-end cameras pass camera control over SDI) it would take special programming on the converters for them to translate the HDMI camera control protocol to SDI or vice-versa. It would certainly be something BMD would be capable of doing, and I would hope that they would do it to provide more options and a smoother upgrade path from the lower-end switchers and cameras to the higher-end stuff. Right now you pretty much have to replace everything at once.

Use Fibre HDMI cables - I use 100m cables and they work perfectly.

This one is available on Amazon for £89
https://amzn.to/2FQwU5g

When you use a atem with SDI connector, you need 2 SDI connection. One for the video /audio signal from the camera to atem and the second from atem to camera with video return. You have also in this signal, the talkback ( audio 15/16 ) and the CCU control.
In atem mini, this second cable use the return wire of the HDMI cable normally used for EDID, remote the switch of the screen, etc to send control signal from atem to the camera. When you transform HDMI to SDI, you loose the return. It's one way only.

Thanks folks for your help here and it's good to know if I want to make the cam work with the ATEM that I need to just go with a longer HDMI cable.

all best, Peter