Blackmagic Forum

Hi all,
I just picked up an Ultrastudio 4K (second hand but brand new in box never been used on a gig) to run graphics at a rowing event next month and I'm having difficulty with an external key/fill at 1080 50p.

I am running png assets out of Qlab 4 with LiveKey (set to external key) on a MacBook Pro 2018. When I set the output surface to 1080 25p in Qlab it works beautifully. I get a good clean black and white key and a crisp fill out of the SDI A & B. However when I change the US4K through Qlab to run at 1080 50p the fill still works, but the key turns into this strange washed out grey image and has vertical lines across it (see picture below. Yes I'm using Donald Trump's face to test it.) I am testing the key by plugging the SDI directly into a Shogun so I know that this issue is occurring before the signal reaches my ATEM TV Studio.

I've tried swapping out the cable, trying a different computer, I've reinstalled Desktop Video and rolled it back a few versions and nothing seems to work. Have I got a dud unit?

Early versions of the UltraStudio 4K firmware did not support keying in 1080p50/60 resolutions. According to the Desktop Video release notes, this support was added in Desktop Video 10.9.5:
https://www.blackmagicdesign.com/suppor ... f1ceccd30f

So you might try that specific Desktop Video version (just in case something about the keying support was broken in later releases).

Also, you will likely need to set the SDI output format to Single Link (rather than Dual Link) in the Desktop Video utility to make sure that it outputs 3G SDI over a single cable.

You could also try testing with the Blackmagic LiveKey utility (included with Desktop Video) to see if you get any different results than you do with QLab.

Hi Dave,

Thanks for the response. I rolled back the firmware to 10.9.5 but still got the same output. I changed the sdi output to single link and that didn't seem to work either. I am also wanting to do my key as an external key inside an ATEM TV studio anyway which requires two sdi cables connected to the switcher. I am running livekey alongside qlab already.

I have this same issue, sirkendizzledid you ever get it to work properly?

I have the same setup as you and I just simply can not get it to work :-/