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Ursa Mini 4k flashing noise and distracting pattern noise

PostPosted: Sun Jan 01, 2017 11:49 am
by Michael Daeché
Ahoy folk!

Had the URSA mini 4K for a little while now, and while I at times love it to bits, at other times it's near impossible to work with.

After being knocked back by Blackmagic tech support, reaching out to the forums to figure out what is normal and what is not, and maybe if there's someone else I should contact regarding my problems.

Flashing is visible in the shadows-dark mids @ 400 (native) and 800, with lines running through the image in the shadows at 200, 400 and 800. This is all being shot at ProRes 422LT (issue is apparent in all ProRes modes)

youtube.com/watch?v=nPwGxe0eCKM (Shot at 25f, 800 ISO, lit by exterior window, no artificial lighting at all. This issue is present at ISO 400 also, but shot at 800 to demonstrate it more easily)

I'm fine with having a noisy camera, as I can fix noise or accept its presence, what I cannot accept is an imagine that flashes from dark to bright to dark to bright. That's just not acceptable.

Also have attached photos of the pattern noise in 400 ISO for a recent shoot. I don't think ABC were very impressed with the footage either..

In all examples camera has been powered with V-lock battery, and same issues are visible with direct power.

Thoughts on this would be wicked appreciated, thanks folks!

-Michael

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Tue Jan 03, 2017 8:47 pm
by rick.lang
The URSA and URSA Mini are not designed as studio broadcast cameras. The SDI Out is primarily intended to support a director's monitor or even a grading monitor, but not intended for live broadcast. BMD does offer studio cameras, but you're using a cinema camera. That said, someone may be able to help you out. I saw nothing unusual in the magnified still photo and the YouTube video was not a good presentation of what you are claiming so difficult to comment on it constructively.


Sent from my iPad using Tapatalk

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Wed Jan 04, 2017 12:05 am
by Earl R. Thurston
rick.lang wrote:The URSA and URSA Mini are not designed as studio broadcast cameras.

Uh, Blackmagic indeed pitches the URSA Mini as a live production camera. They even have a studio viewfinder specifically for the task:
https://www.blackmagicdesign.com/products/blackmagicursamini/liveproduction

Even so, the original poster mentioned the footage was for ABC, but didn't say anything about studios, broadcasting or even SDI.

rick.lang wrote:I saw nothing unusual in the magnified still photo and the YouTube video was not a good presentation of what you are claiming...

The still image very clearly shows a large amount of pattern noise, mostly as horizontal lines. The YouTube video isn't ideal, but I can see what was intended -- the shadow areas can be seen jumping between levels.

Both of these issues I've seen personally in my testing of an URSA Mini 4K in the fall. I think they're simply limitations of this specific camera and sensor.

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Wed Jan 04, 2017 4:11 am
by rick.lang
Earl, how does Britney Spears put it? "Oops, I've done it again!" Yes, I was completely forgetting that option! Shame, shame, shame.

When I made my comments about my view of the video and still image, it's based on looking at it on my iPad Air and it doesn't dance there!


Sent from my iPad using Tapatalk

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Thu Jan 05, 2017 11:21 am
by Michael Daeché
Thanks for the insight, Earl! That's a massive shame, as not being able to record at ISO 400 is critical for me in my line of work. Didn't realise this camera would perform so poorly, will have to get another loan and look into some other solutions for sure.

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Tue Mar 13, 2018 6:02 am
by gardnsound
What did you end up doing about this, Michael?

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Tue Mar 13, 2018 4:08 pm
by Denny Smith
The bottom Line is, the UM4K is not an available, low light camera, the sensor needs a minimum amount of light, even in the shadows to prevent the pattern noise. A strong widow light is nice, but shadows caused by it need some fill, either bounce or other lighting means.
Cheers

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Wed Mar 14, 2018 3:27 am
by gardnsound
Denny Smith wrote:The bottom Lin is, the UM4K is not an available, low light camera, the sensor needs a minimum amount of light, even in the shadows to prevent the pattern noise. A strong widow light is nice, but shadows caused by it need some fill, either bounce or other lighting means.
Cheers


I'm more interested in the jumping flashing noise. My camera is (even with the lens cap on) jumping big time. The picture quality looks like a ******* VHS cam-corder. I sent support some raws - I can provide that here, too:

https://drive.google.com/open?id=1sXf1S ... ETgG81aOo5

Even when I flood the scene with light, it's still jumping big time in the shadows, blacks especially.

Re: Ursa Mini 4k flashing noise and distracting pattern nois

PostPosted: Wed Mar 14, 2018 4:34 pm
by Denny Smith
Then that sounds like a camera issue then. Please keep us posted on what Supoort responds with. Hope you are able to get it sorted.
Cheers