Weird pulsing artifacts Broadcast G2

Hey guys,

Recently we've upgraded to Ursa Broadcast G2's at work (local news network)

We're shooting on SD cards, Sandisk Extreme Pro, 300mb/s. 1080p, BlackMagic Video.

Recently, we've noticed some artifacts appearing in wide shots specifically (see bottom right corner, roof of house). we've got detail sharpening on low. These artifacts are only visible after transferring media into our system. They do not show up in camera.

https://drive.google.com/file/d/1nqAGe0 ... drive_link

Has anybody experienced this before/have a solution? I'm used to my personal kit, the 4.6k G2, and only shoot with CFast cards so I'm not as clued up with the broadcast versions and SD cards. I suggested them as a media solution but I think the head honchos wanted to pinch pennies and went with the SD cards. If this turns out to be the issue then I guess they're dropping some cash.

Cheers to anybody that can help.

I can't see your video clip - it's asking for access permission.

But I can say that's it's unlikely to be media at UHD ENG rez. It's most likely aliasing from the sensor. I fitted a Rawlite OLPF to my UBG2, not because the aliasing is particularly bad but because it doesn't have one and professionally I'm used to cameras having one. And rooftop tiles at a distance are the classic stress test for aliasing.

Aliasing is a huge QC fail for any broadcast work and notoriously difficult to get rid of, in post. It may not even look bad sometimes or even hardly noticeable on the original camera takes but the concatenation of codecs down through post and out to broadcast will amplify it hugely. This is most likely why the 12K Ursa was not Netflix approved until they fitted one of their own design - now it's on the list. I said as much at the time and even though others disagreed here, BMD were listening.

Anyways from what you say your employers are maybe too tight to buy and fit them (around 600 euros + plus the torque screwdriver) but I am pretty sure that's your issue; and the only solution for broadcast too; obviously with the coda I have not seen your video.

I can't see your video clip - it's asking for access permission.

But I can say that's it's unlikely to be media at UHD ENG rez. It's most likely aliasing from the sensor. I fitted a Rawlite OLPF to my UBG2, not because the aliasing is particularly bad but because it doesn't have one and professionally I'm used to cameras having one. And rooftop tiles at a distance are the classic stress test for aliasing.

Aliasing is a huge QC fail for any broadcast work and notoriously difficult to get rid of, in post. It may not even look bad sometimes or even hardly noticeable on the original camera takes but the concatenation of codecs down through post and out to broadcast will amplify it hugely. This is most likely why the 12K Ursa was not Netflix approved until they fitted one of their own design - now it's on the list. I said as much at the time and even though others disagreed here, BMD were listening.

Anyways from what you say your employers are maybe too tight to buy and fit them (around 600 euros + plus the torque screwdriver) but I am pretty sure that's your issue; and the only solution for broadcast too; obviously with the coda I have not seen your video.

Sorry mate! That link should be fixed now.

We do get aliasing, but this is something I’ve never seen before. Scrubbing through the clip, the effected area almost looks like a proxy. You’ll see that it’s not your classic aliasing, as it’s happening on a fixed part of the frame.

Keep in mind it doesn’t matter the setting, it’s only whenever we’re shooting as wide as we can go. Grass, interior, interview, whatever. Almost like the bottom right/lower middle of the frame is corrupted. If we zoom in, we can actually crop out this artifact.

Ah yes, I see what you're saying now Issac. That's a curious one and does look like media corruption. Have you been able to try different media? Access to a CF card or an external SSD? Were these cards almost full; formatted in the UBG2?

That's a tough scene for low bitrate H.264 at 50fps. Does it go away if you record at the highest setting? "H.264 SDI" as they call it. Why not record to ProRes? I think that camera supports it.

That's a tough scene for low bitrate H.264 at 50fps. Does it go away if you record at the highest setting? "H.264 SDI" as they call it. Why not record to ProRes? I think that camera supports it.

Yes I'd be curious if UHD H265 SDI exhibits the same; a sensor issue could be ruled out at least if other codecs/rez play fine. Prores is pretty storage intensive on cards, Roger but worth a test. SDI H264/5 are 10 bit 4:2:2, which matches broadcast delivery specs of other makes such as Sony, with broadly similar bandwidth, on similar codecs normally used in those cameras for long form broadcast. You have to use Prores HQ for the same bit depth and sampling (or Braw - impractical in these cases); and although much better is a huge card space swallower.

That's a tough scene for low bitrate H.264 at 50fps. Does it go away if you record at the highest setting? "H.264 SDI" as they call it. Why not record to ProRes? I think that camera supports it.

Yes I'd be curious if UHD H265 SDI exhibits the same; a sensor issue could be ruled out at least if other codecs/rez play fine. Prores is pretty storage intensive on cards, Roger but worth a test. SDI H264/5 are 10 bit 4:2:2, which matches broadcast delivery specs of other makes such as Sony, with broadly similar bandwidth, on similar codecs normally used in those cameras for long form broadcast. You have to use Prores HQ for the same bit depth and sampling (or Braw - impractical in these cases); and although much better is a huge card space swallower.

I’m pretty sure ProRes was ruled out due to the file size.
I’m going to give this codec a go today and see what happens. Will update if we get somewhere!
Unfortunately I’m just the driver in this scenario as these kits need to be uniform across the network, but I’ve been given the green light to experiment and report back to our tech. The reason it’s so involved is that we’re technically a regional crew so most of our support and operations is out in a separate state.


Thanks to all who have offered suggestions!