Davinci Keying without noise

[Christopher Adams]

One thing you can try is to add a node with higher saturation and key it then after keying reverse the saturation boost. We are using 32bit float here after all.
I find sometimes it locks on to things better. Also. what kind of footage was it? I find that that will totally effect what you can and can’t key well. Another thing you can try is to do a noise reduction prior in the chain from doing your isolations. Or hell if its a bad clip run it though something like MB-denoiser or my favorite Neat video plugin. Then try keying. I suspect that it will help.
Just a few ideas. NOTE DLSR footage is some of the worst! to key on. ITs lossy 8bit H.264 breaks down quickly.
CJ

[Joseph Mastantuono]

Chris Adams makes a good point.

DSLR H.264 footage is a main offender. It’s so smushed down that any sort of keying is next to impossible.

Joseph Mastantuono
http://www.goodpost.net
Color Grading & Post Production Consulting

[Sean Ross]

Thanks Christopher. Good advice.

One thing you can try is to add a node with higher saturation

I have tried this in other color correctors. I will try it. Although instead of resaturating/desaturating I will do what I do with the noise reduction and split it off as a separate node tree which feed back to the main tree as a matte (or a series of mattes).

–sean

[Sean Ross]

I forgot to mention, its Arri Alexa 444 footage.

[Robert Ruffo]

I think curves would likely work better than linear fall-off. It’s easier to change, say, the color of a shirt in the Hue vs curves than in HSL, probably because the falloff is smoother an d easier to control as it uses curves.

To those who say changing a shirt color, for example, should be VFX and is not part of grading: I say 1998 is over. People expect the color session to be able to affect all things color, and being able to pull clean secondaries is very much part of that.

I also agree that the sat controls seem almost broken and do not work as expected at all.

Overall, I would prefer slower but better performance – the expectation of pure 100% realtime is no longer there – tapedeck days are over – it doesn’t really matter. Just give me quality. Maybe give me a “high render” option on the HSL that would be slower but cleaner?

[Michael Stirling]

You could also try pulling the key in an ‘alpha node’.

In the key node (3) add loads of saturation and Radius blur and actual Blur.
In the output node (2) check the invert box in the post mixing part of the key page.
It just takes the strong key, not the blur or the saturation.

I agree with comments about the NR – I’ve only ever used it on RED footage successfully. Anything else I use Neat in FCP.

~M

[Joseoscar Sanchez]

Hi sean!
Just a thing to consider that works for me. I use the 3D qualifier for chroma. But, I do not use the “Despill” option because it introduces a lot of noise to the Key! If I have to supress the spill, I make another node and correct the green or blue spill using the color wheels.

Hope this works for you!
God bless!

Oscar Sánchez

[Tero Ahlfors]

This is a six year old thread. 3D keyer wasn’t even a thing back then.

[Joseoscar Sanchez]

Ooops I didn’t noticed… But it is still an issue in version 14! ☺ Try it and you will see.

[Marc Wielage]

The key mixer can help refine chromakeys and stuff like that. There’s some tutorials out there on the web.