Blackmagic Forum

Hi everyone,

My church just recently bought a new iMac and connected to our 1ME like this:

USB-C port => thunderbolt 3 to HDMI adapter => AJA HDMI ROI => SDI INPUT @ 1ME

The signal from the iMac on our 1ME was flickering. When we use an older mac with thunderbolt2 port, this issue did not arise.

I tried connecting the new iMac directly to input 1 @ 1ME via HDMI also yield flickering.

I tried connecting a VideoAssist 4K to the new iMac and it also flickers.

If the thunderbolt2 port can make it work, the new USB-C port should work too right?

How do I solve this issue without purchasing a Ultrastudio?

Thank you

regards,
Kee Sitt

What resolution and framerate are you using on your mac and what is the atem configured too?

mac: 1080i 50hz
atem: 1080i50

I went to Apple Store today and took my VideoAssist to see if this was an isolated problem.
I plug into their store demo units. Long story short, the results was:

iMac 27" - No Flicker
iMac 21" - Flicker (this is the same specs as our iMac)
MBP 15" - No Flicker
MBP 13" - Flicker
MBA 12" - Flicker

I am suspecting that the Macs that has the Radeon Graphics Card does not flicker. The ones with the Intel Iris Graphics Card reproduces the flickers. The Apple Store technician and supervisor could not answer me and its their first time seeing this.

Appreciate it if any of you or BMD staff could test this out to verify my findings is true?

Thank you

regards,
Kee Sitt