Problem Keying with Keylight in AE

Problem Keying with Keylight in AE

on Nov 23, 2011 at 11:20:59 am

Hi there,

I'm working on a key in AE using Keylight. I've had good results before, but this time it's not coming out quite as well. I don't know if the footage is partly to blame, the green screen itself is a bit too in focus in my opinion.

I've keyed with Keylight and then added a light wrap effect and graded using Magic Looks - please see the attached images.

Can anyone advise any improvement on my settings or alternative/additional effects?

I can provide more info if useful.

As usual, crushing deadline/client/panic/stress/etc.

Re: Problem Keying with Keylight in AE

by Steve Blacker

on Nov 23, 2011 at 3:08:14 pm

You're keying out the green screen so it can be placed on a green background?

I would put your screen gain back to 100, and try adjusting the clip black/white levels (usually start around 10/90 and go from there). You could also try to adjust the screen shrink/grow to a negative number to reduce the fringing, and a screen pre-blur of 1 to 3 pixels might help a bit, too.

It's only work if you'd rather be doing something else...

Re: Problem Keying with Keylight in AE

on Nov 23, 2011 at 3:41:25 pm

"You're keying out the green screen so it can be placed on a green background?" lmfao!! Yup... Welcome to my world...

Thanks for the advice! I'll give this a try.

I understand the footage was shot on (Sony PDW350) XDCAM HD 422, so I think it's long GOP.

Re: Problem Keying with Keylight in AE

by Steve Blacker

on Nov 23, 2011 at 3:09:29 pm

Also give "Hard colour" a try under "Replace method". Sometimes that helps in my experience.

What's your source footage? Could just be the quality of the footage making it hard to get a decent key.

It's only work if you'd rather be doing something else...

Re: Problem Keying with Keylight in AE

by Michael Szalapski

on Nov 23, 2011 at 3:14:53 pm

You might explain what type of look you're going for and why what you currently have isn't making you happy. Also, I don't understand what you mean by the green screen being too much in focus...

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

Re: Problem Keying with Keylight in AE

on Nov 23, 2011 at 3:46:07 pm

The cropped shot I uploaded isn't very clear, but the actual green screen ie the cloth, is almost in full focus. I've always worked with shots where the screen is placed further back and kept out of focus.

In terms of aim, I really just wanted to check that the method I've followed seems reasonable and that I've done I can reasonably do with the footage in the time allowed.

Re: Problem Keying with Keylight in AE

by Steve Brame

on Nov 23, 2011 at 3:19:58 pm

You might also try changing the order of your effects. Of course Keylight should be first, but the stacking order of the 'Light Wrap' and 'Looks' might be causing an issue.

Steve Brame
creative illusions Productions

Re: Problem Keying with Keylight in AE

on Nov 23, 2011 at 3:43:22 pm

Yeah I was think about this. I've got the footage pre comped with the light wrap settings and then looks applied on top.

Re: Problem Keying with Keylight in AE

by Roland R. Kahlenberg

on Nov 23, 2011 at 3:29:52 pm

Apply the Reduce DV Blockiness Animation Preset prior to Keylight. Then follow the other recommendations as required.

HTH
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer

Re: Problem Keying with Keylight in AE

by Tudor "Ted" Jelescu

on Nov 23, 2011 at 7:18:12 pm

After all the great advice you got, I would consider on more option, use a Matte Choker or Refine Matte (I believe CS5 and up has that only)to clean up your edges.

Tudor "Ted" Jelescu
Senior VFX Artist