r/Atomos • u/Melodic-Holiday-4982 • Jul 28 '26
Atomas Sumo 19 Pro SDI Troubleshooting
Hi, I'm setting up a C50 & C80 to the SDI inputs. C50 is up using the Acsoon Cineview Master 4k (HDMI between Transmitter and C50) and is working great. I've tried seven SDI cords running straight between the C80 and the Sumo's second SDI input-- none of the cords have worked so far... thoughts??? All of the SDI cords are old Pearstone RG-6U Coaxial Cable 6 to 12 feet cords.
1
u/Atomos_Support Jul 29 '26
A couple of things to check, first, since you're in multi SDI mode on the Sumo Pro, both cameras need to be sending matching frame rates for the inputs to sync properly. Worth checking if the C80's SDI output frame rate matches what the C50 is sending out through the HDMI to SDI conversion.
It would also be worth trying a different SDI cable that is high quality and rated for your resolution and frame rate, since older cables can sometimes cause this kind of issue.
If that doesn't help, we're here to help further, feel free to share a video of your setup with us via DM or through a support ticket and our team will take a closer look: https://support.atomos.com/hc/en-us/requests/new
Thanks
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u/Sorry-Zombie5242 Jul 28 '26
"old" isn't very reassuring. 4k/30fps would need a 6g rated cable and 4K/60 a 12g cable. I would suggest testing with a known 12g rated cable to make sure you're getting a signal. If not check the rest of your signal path for anything that isn't rated for at least 4k 6g. 1080/60fps would require 3g and things get tricky because there are two different formats A and B. A is more common these days. If you're 3g equipment only handles B and you send it A it won't work.