Bmpcc6k pro Strong Banding issue

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tomlight

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Bmpcc6k pro Strong Banding issue

PostSat May 15, 2021 8:57 pm

Hi,
in my BMPCC6k PRO sometimes I have a strong banding problems as you can see from attachments (line are Red because of the Focus Assist is turned on). Sometimes is strong, other times is subtle and I can barely see it. The problem is that I don't know how to recreate it, it happens suddlenly for a few seconds and then it stops.

It's not on the monitor but on the recorded files: both braw and prores.

Any advice?

[url]
https://drive.google.com/file/d/1SibHNb ... sp=sharing[/url]

https://drive.google.com/file/d/1SibHNb ... sp=sharing

thanks
Attachments
Schermata 2021-05-15 alle 22.55.19.jpg
Schermata 2021-05-15 alle 22.55.19.jpg (80.35 KiB) Viewed 806 times
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Robert Niessner

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Re: Bmpcc6k pro Strong Banding issue

PostSat May 15, 2021 9:27 pm

I'd say contact Blackmagic support. Hard to say what's going on here.

BTW, that is NOT banding. Banding is when you can see steps in a color gradient
Saying "Thx for help!" is not a crime.
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Robert Niessner
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tomlight

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Re: Bmpcc6k pro Strong Banding issue

PostSat May 15, 2021 9:48 pm

Thanks Robert for your advice, I will contact BMD support.
How would you call this kind of problem? I know banding is a different thing but I wonder how it can be named.
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Robert Niessner

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Re: Bmpcc6k pro Strong Banding issue

PostSat May 15, 2021 10:34 pm

Maybe it can be called lines of interferences. But I think we need some help here from English native speakers.
Saying "Thx for help!" is not a crime.
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Robert Niessner
LAUFBILDkommission
Graz / Austria
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Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
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rick.lang

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Re: Bmpcc6k pro Strong Banding issue

PostSat May 15, 2021 11:17 pm

Are the lines stationary or moving down the screen?
Rick Lang
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tomlight

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Re: Bmpcc6k pro Strong Banding issue

PostSun May 16, 2021 8:44 am

Lines was moving with different amplitude.

[url]https://drive.google.com/file/d/1SibHNbQkuf7NxUV2aZpYA2uSJPAc_VTo/view?usp=sharing/url]
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Johannes Jonsson

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Re: Bmpcc6k pro Strong Banding issue

PostSun May 16, 2021 3:12 pm

As Robert said, this looks like interference floating around the screen and the focus assist makes it look red colored.
Johannes
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tomlight

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Re: Bmpcc6k pro Strong Banding issue

PostMon May 17, 2021 7:34 am

I'm trying to replicate the problem and I noticed horizontal interference visible in particular at iso 800/1000 (far less visible at iso 5000 and beyond). The video below was shot with no lights and you can see the horizontal interference

https://streamable.com/xbgak7
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Howard Roll

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Re: Bmpcc6k pro Strong Banding issue

PostMon May 17, 2021 12:00 pm

It looks a lot like EMI. You can see the interference tracks with the position of the camera at 7-9 seconds. Watch it in slow-mo, the camera pans into the interference and the band of noise propagates until the blacks are saturated, then as the camera is panned back across the same spot the interference unloads in reverse. This is about where it starts.

emi.jpg
emi.jpg (76.3 KiB) Viewed 402 times


These cameras seem a little sensitive to EMI, or RF, or something. The camera is powered internally, is it connected to anything else like a recorder or TX? Sometimes a simple ferrite choke will be sufficient for removing EMI on the wire. If the camera is picking up EMI/RF internally another solution may be in order.

signs.jpg
signs.jpg (153.92 KiB) Viewed 402 times


Good Luck
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tomlight

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Re: Bmpcc6k pro Strong Banding issue

PostMon May 17, 2021 12:40 pm

Thank you very much Howard for your explanation.
Before the BMPCC6K PRO pro I had the regular 6k but I had never had this problem.
The test I did was shot in natural light and the camera was powered internally by the original battery.Nothing was connected to udbc or hdmi.
I have now tried to approach a small ferrite chokes as you suggested but I can't see any change. However I think a malfunction like this is not acceptable. I wrote to BLACKMAGIC and I'am waiting for a reply.
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Kristian Lam

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Re: Bmpcc6k pro Strong Banding issue

PostTue May 18, 2021 2:33 am

Hi tomlight,

This is not acceptable. I would definitely RMA this camera. Please PM me your ticket number if you have already lodged a support ticket.
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tomlight

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Re: Bmpcc6k pro Strong Banding issue

PostTue May 18, 2021 8:03 am

Thank's Kristian for your help. The ticket number I received after the support ticket (found in the automated response email) is:

[Support #KOO-685-41528]: Strong Interference/Banding BMPCC6K PRO

I hope this help.

thanks

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