Keying against white pros and cons

[James B.]

For a current music video project will be filming talent against a white infinity cyc ala Apple commercial. I may opt to key out this background in post.

If I were 100% certain I'd need to key out the background, what would be the advantages of using greenscreen over totally white background when shooting?

 

[Scott Crawley]

On a white cyc/luma key:

Your talent can't wear white. This goes beyond the inconvenience of changing a shirt. It extends to sneakers, shoelaces etc. If you want to include even one full length shot (and you know you do) don't forget the shoe laces.

You may have the problem of keying out their eyes and teeth

No white props (more guitars have white pick guards, knobs etc. than you might notice.)

Any over exposure error will key out, but I assume that won't happen... Not even a glint off of jewelry or an instrument


It's a start.

 

[Bob Gundu]

Pros... no green spill.
Cons... there may be some holes that a hold out matte couldn't fix.

 

[Scott Crawley]

I would set the white cyc up and attend to all of the details and the talent would show up shimmering like a disco ball wearing some big ass piece of trademark jewelry that they can't do without, sporting the shiniest gold tooth you ever saw or some other crazy shit.

I'm lucky like that

 

[Andrew Gentle]

You can get a pretty convincing white cyc look from a greenscreen anyway, and you'll have more options.

 

[PatrickFaith]

Since I shoot monochrome, what I sometimes do is completely blow out(totally overexposed and clipping) my white background and shoot my foreground in the greys ... is super easy to key that way (i.e. full sun white background with my foreground is shaded, i create a simple expression in nuke to create the alpha mask). Even foreground whites are not blown out so don't get alpha applied (i sometimes do this with the sky by having the sky totally overexposed, that way i don't even have to put background screens up if i a replacing background hills/mountains/buildings). I think using white as a alpha creates a better feel in the composite, but only works in specific situations.

 

[Paul Schneider]

You really don't want to key against white or black unless you want to be doing roto.
Do yourself a favor. Use digi green, make it nice and even, keep it far from the subjects & light it well. Spill is avoidable if shot correctly and is relatively easy to correct.

 

[Scott Crawley]

When you do that, do you key the green or desaturate and luma adjust it as needed?

You can get a pretty convincing white cyc look from a greenscreen anyway, and you'll have more options.

 

[paulherrin]

use the greenscreen unless you're 100% about NOT keying

it's preferable to have a background plate on hand to match lighting. it's also preferable to make creative decisions in pre-production, that just leaves you room to be flexible in production and post.