Does FCP degrade 10 bit files/clips?

[David Roth weiss]

[David Smith] “I created a new Project in FCP: 10 bit uncompressed.

I then created a black to white gradient: The “A” button in the bottom right of the viewer > Render > Gradient. I now have a 10 second black to white gradient in my viewer WITH NO BANDING (at first I thought this was strange because I was on my cheaper, DVI, user interface monitor – but then I thought I was in B&W – with no color).

I then dragged the clip to the timeline. The same clip in the canvas window now has A LOT OF BANDING. OK, well it needs to play in real time right?. “

Please go and check the Sequence>>Settings and report the main stuff you see there. I’ll bet you bottom dollar the sequence is not 10-bit uncompressed. Sequence 1 is never set correctly even after setting-up the proper Easy Setup.

David Roth Weiss
Director/Editor/Colorist
David Weiss Productions, Inc.
Los Angeles
https://www.drwfilms.com

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[Rafael Amador]

[David Smith] “I then created a black to white gradient: The “A” button in the bottom right of the viewer > Render > Gradient. I now have a 10 second black to white gradient in my viewer WITH NO BANDING (at first I thought this was strange because I was on my cheaper, DVI, user interface monitor – but then I thought I was in B&W – with no color).

I then dragged the clip to the timeline. The same clip in the canvas window now has A LOT OF BANDING. OK, well it needs to play in real time right?. “
FC’s Generators (Gradients) are 8bRGB.
They will cause banding.
Apply to the gradient some “Gaussian Blur” (only to the RGB channels).
Set “Render in High Precision”.
Rafael

http://www.nagavideo.com

[Jeremy Garchow]

You will not see a correctly displayed 10bit image on your computer monitor. Period.

If you have a capture/output card and a 10bit capable monitor, then you can accurately judge what you are seeing.

I will disagree with Rafael in that when rendered, the gradient is indeed 10bit. When you put it on a timeline without rendering, FCP will display what it always does in the rt engine, and that’s 8 bit.

Jeremy

[David Smith]

“Please go and check the Sequence>>Settings ”

10 bit uncompressed

“You will not see a correctly displayed 10bit image on your computer monitor. Period”

It is not a 10 bit monitor, that’s not the point. There is no banding whatsoever in the the viewer. There is in the timeline/canvas. When I export the 10 bit uncompressed sequence and put that new clip in the viewer there is banding. I can not export a clip that looks as good as the one in the viewer.

I do have a Quatro 4000/Decklink > SDI > HDlink > 10 bit monitor. It looks the same on that one.

I’ve heard that FCP does this. I’ve just never seen it myself. If anyone can tell me how to do it so I can make a clip that looks like the one in the viewer let me know.

Or, try it yourself. I’d be curious to see what other people get.

[Jeremy Garchow]

[David Smith] “It is not a 10 bit monitor, that’s not the point. “

You can’t watch 10 bit material on an 8 bit monitor.

[David Smith] “There is no banding whatsoever in the the viewer. “

Challenge!

[David Smith] “I do have a Quatro 4000/Decklink > SDI > HDlink > 10 bit monitor. It looks the same on that one. “

That’s not a 10bit signal path unfortunately.

[David Smith] “I’ve heard that FCP does this. I’ve just never seen it myself. If anyone can tell me how to do it so I can make a clip that looks like the one in the viewer let me know. “

If you use a gradient, put it in a 10bit timeline, and render it, then export at current settings in 10 bit. the onyl way you can check is through an honest to goodness 10b signal path.

[David Smith] “Or, try it yourself. I’d be curious to see what other people get.”

I have, it’s 8 bit until I render in a 10b timeline.

[David Smith]

“Challenge!”

I need to drop the whole 8 bit, 10 bit issue. I’m just saying there is no banding in the viewer. When you drag it to the canvas, there is banding – when you export it and reintroduce it to the viewer there is banding.

My user interface monitor is a 23″ LG IPS236 IPS LED. It is 8 bit. It is connected by DVI. There should be banding. I’m just saying there is none – in the viewer.

But 8 bit has to do with color. This is not color. To be honest I don’t know how B&W banding looks on an 8 bit monitor – maybe there are only 256 shades of gray. All I can say is there is no banding in the viewer. I was as surprised by that as anyone doubting that I can see no banding on an 8 bit monitor.

If I do this: If I have my unbanded gradient in my viewer and add a 3 way color correct video filter… without doing a thing to it. It still looks B&W. Then suddenly there is banding.

I’m still curious if anyone else gets the same results.

[David Smith]

“[David Smith] “I do have a Quatro 4000/Decklink > SDI > HDlink > 10 bit monitor. It looks the same on that one. ”

That’s not a 10bit signal path unfortunately.”

Which part of it is not 10 bit?

[Jeremy Garchow]

[David Smith] “To be honest I don’t know how B&W banding looks on an 8 bit monitor – maybe there are only 256 shades of gray.”

That’s exactly what it is, it doesn’t only have to do with color, but also shades of grey.

Is is true the canvas is different from the monitor, when I do this, I have banding in both, but not on my 10b external monitor. Seriously, it’s the only way you can judge. Take what you think is the bad export to a 10bit capable output facility, and watch that there’s no banding, even though it shows it on your computer monitor.

I am not lying to you.

Jeremy

[Jeremy Garchow]

The mac drivers and the quadro 4000 are not 10bit so it stops right there. DVI is only 8 bit capable.

You need a i/o device form AJA, Blackmagic, Matrox, etc hooked up to a true 10bit panel (some of them fudge the truth and say they are 10 bit, when they are not. They might process in 10b, but they display 8b).

Jeremy

[David Smith]

I have a i/o Blackmagic Decklink and the monitor for grading is an NEC PA241w – which I’m going to have to take their word for it is 10 bit.

For that monitor I’m not connected DVI I’m connected SDI > Blackmagic HDLink (which they claim is 10 bit) > Display Port.

I’ve head Macs can’t handle 10 bit. I’m setting up my system right now. What I don’t understand is: If a Mac Pro is not 10 bit what are people using to color grade 10 on?

Like I said, I’m setting it up right now, so finding the weak link it what I’m after.