Hey, guys!
Is there someone here so enormously generous and kind to trim a 5 sec. HVX200 greenscreen, QT sample for me? I only need a tiny DVCPRO bit.
I would only use it in a class.
Possible?
Thanks in advance.

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

Yes. E-mail me.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
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Thank you so much, Shane!

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

did you get that clip yet? if not i have one ready

I got one to him.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
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hey shane could i get a green screen clip from you also?

if its possible do you have an outdoor and indoor shot as well??

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

e-mail me.

Sorry, outdoor only. Perhaps wayne has an indoor one.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
[itunes.apple.com]

Shane's clip is perfect. Thank you so much!
Wayne: getting another sample wouldn't hurt at all. Possible?

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

do you need it in pal?

Any frame rate is perfect, since i'm not going to use it for anything but a class.

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

[understandinc.com]

its there in native NTSC dvcproHD format. its a dude with slightly spikey hair waving his fingers to do fine detail keying with.

if youre going to key in FCP i HIGHLY suggest dvmattepro - it kicks the snot outta the built in FCP keyer

Thank you much, Wayne!
Downloading now.
I'm going to use Keylight in AE. It worked perfectly with Shane's clip.

I don't need to achieve super VFX level keying, with light wrapping and such things. As I said to Shane, I just want to show to my students the advantages of (affordable!) 4:2:2 color sampling for these things.

Thanks again!
This forum is great

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

AE with Keylight. Beats the HELL out of DV Matte Pro (IMHO).

I used Shake with the same...Keylight.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
[itunes.apple.com]

Wayne: is that green paint, or one of those self-illuminated backgrounds? It looks really good!

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

Shane.

I'd love to get my hands on a sample as well.
Looking into buying that camera next week and using that as a demo to persuade my superiors would be perfect.

Johan Polhem
Motion Graphics
www.johanpolhem.com

e-mail me.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
[itunes.apple.com]

is green screen better than blue?

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

long story short, Green is more flexible, especially for mattes. Better for video. Blue is quite nice for flesh tones and film. Green is more forgiving than blue. We can get all geeky here, but generally Green and video go together like peas and carrots. Blue and video go together like peas and asparagus.

Michael Horton
-------------------

Green is better for video because the color range in Green is wider than Blue when filming digitally.
The opposite is true for Film.

At least thats how it was explained to me.

Johan Polhem
Motion Graphics
www.johanpolhem.com

no Adolfo, that clip uses a foam backed green material lit with two kino flows. i dont know if you backed out a step of that link i sent, but if you go here:

[understandinc.com]

there is the above clip AND two source/keyed samples one from the foam+kino and one from the self-illuminated backgrounds (reflecmedia). personally id only choose to use the reflecmedia if time and space made the traditional method impossible

Thanks again, Wayne.
The color sampling works very well for keying. That's great. I'm also finding higher than expected (expected by me, I mean) noise/artifacts. That black shirt is tough to handle, apparently
Other than that, it works beautifully. The semi-transparent detail Keylight is giving me for the hair wouldn't be possible with 4:2:0.

As for the green vs blue thing, isn't it precisely because a 4:2:2 YUV color space has much higher sampling in the green channel?

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

Adolfo.

That is true.
In low-end formats (4:2:2 and below) the blue channel is more compressed than the green channel. Blue is also the color of the "noise" in these codecs, making a blue key much dirtier.
But green also requires less light to be illuminated, making it cheaper and easier.

Blue is good for uncompressed formats like film or 4:4:4 HD since the human skin contains no blue but is rather a mix of green and red.
(Although blue/green is more a matter of DOP preference at that level than anything else)

And you're right the difference between 4:2:2 and 4:1:1 or 4:2:0 is enourmous.
You simply cannot get a good key with anything below 4:2:2 where even though luma is sampled on every pixel, color is sampled on every second pixel. In 4:1:1 for example color is only sampled every fourth pixel making the edge of the key very unpredicateble usually leaving you with a black border around your foreground subject. (Which you can choke but that is cheating and ruins the image)
And furthermore, some 4:2:2 codecs is also 10-bit which means that every color has 1024 variations whereas 8 bits only offer 256 cvariations. (Digi Beta for example)
THis obviously helps to reduce dirt around the edges of your key.

Johan Polhem
Motion Graphics
www.johanpolhem.com

Hey, Johan.

Everything is true but this bit:
"And furthermore 4:2:2 is 10-bit which means that every color has 1024 variations whreas 8 bits only offer 256 cvariations."

4:2:2 doesn't imply 10 bit color. There are only a few 4:2:2 formats which are 10 bit. Digibeta is one of them. DV50 and DVCPRO HD are not, for example. In terms of production codecs, well... FCS has an 8 bit uncompressed 4:2:2 and a 10 bit uncompressed 4:2:2 codec.

Also, 4:2;2 low-end, huh?
In depends on which world one lives in, I guess.

Adolfo Rozenfeld
Buenos Aires - Argentina
www.adolforozenfeld.com

True.

I was referring to the Digi Beta codec though and I should have explained that obviously.
(I have changed it above)



"Also, 4:2;2 low-end, huh?
In depends on which world one lives in, I guess."

Yes. But for greenscreen purposes 4:2:2 is the bare minimum.
I prefer 4:4:4 HD.
The extra time spent on trying to make a 4:1:1 look decent will far outweigh the extra cost of shooting on Digi or higher.
Here in Oz a Digi with an operator is only US$700 per day.

Johan Polhem
Motion Graphics
www.johanpolhem.com

so let me get this strait.

i shoot with the dvx100b ( 4:2:0 i think ). i was about to go out and get the green screen set up. would i be just wasting my time trying to do it with my current cam?

i dont mind the extra work because i figure if i can just get a relatively decent key it would be worth it. the use i have for it doesnt need to be excellent just pretty good. because i will ether be compositing this to black backgrounds, outdoor shoots ( no stock matching really needed cause both are shot with the same dv cam ), and partical backs.

i cant really muster up a hvx right now.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

"i shoot with the dvx100b ( 4:2:0 i think ). i was about to go out and get the green screen set up. would i be just wasting my time trying to do it with my current cam? "

Its all relative to what it will be used for and what your budget is.
You will be able to pull a key it just wont be great.
For some jobs this is good enough.
The lighting will be equally important as the format if not more, so make sure you get that right.

I generally dont bother cause the time spent on trying to fix the 4:1:1 key is worth more money than hiring a Digi Beta and an operator.

Having said that I do key on Mini DV if I am testing an idea for example and I am not broadcasting the results.

Johan Polhem
Motion Graphics
www.johanpolhem.com