green screen

I'm kinda new at this -- and have to do a green screen (basic -- i have host on cameras in front of green and i need to add a mloving video background -- what do i do?)

[www.lafcpug.org]

Pageprod,

new, and green sceen. If this is a paying client then I would do this and understand it before you shoot for the client.

If its for fun and experience thats differerent.


Note that your camera will play a big part in how well the green screen turns out.

If you have a single chip consumer camera, you may not get very good results.

THree chip camera's for this kind of work.



Lonn Bailey

key words here LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, LIGHTING, - did i mention lighting?

and a big room helps as well. id say NO LESS than 16 to 20 feet between you and the green screen.

Also need to think about the format. The age-old is wisdom is that DV will not pull a good key. I know this from personal experience. Due to the color space restrictions of DV, you will end up with the interviewee having jaggy or "stair-step" edges. Some keying software claims it can work with your DV footage, but
frankly, it's not a risk I'd take with a paying job.

If this is for a client, I would seriously consider using a Betacam or a camera like the HVX200. The color space is twice that of DV and therefore allows for much smoother, natural keys. But the camera's not your only issue. You must make sure you have both your subject and the screen lit extremely well.
When I do green screen work, I usually have two 750W softboxes lighting the screen, plus a 500 or 750 lighting the subject from the front, a halo light from the back. Using a good keyer like Primatte or Keylight is also extremely helpful.



www.slantyhouseproductions.com

And moving foreground and background? You might need motion control cameras and reference markers and high end compositing software.

And a good shooting format. DV is the worse for keying.

What exactly are you trying to accomplish?

Yes, dv is the most difficult, but it can work.

"a halo light from the back". Koz added a point a while ago that I'd wished someone had mentioned years before, use a orange filter on that back light and it will help separate the screen from your subject. Makes total sense when you think about it. Opposite side of the color wheel.

Check out DV matte garage. I just used their filter for some HDV footage and was blown away by how clean the composite ended up. I used it in "Motion".

Good Luck!

Kevin



"A problem can never be solved by the same consciousness that created it"
Einstein

Why orange gel over minus-green (magenta)? Is there a reason orange is better?

Nope, I just was told magenta is even better, either is better than a straight light. I just did two interviews in front of of green screen and i wish I'd known before. With dvmatte garage it turned out good, but I wanted great!

Kevin



"A problem can never be solved by the same consciousness that created it"
Einstein

From my experience I can only say:
-Dont under any circumstances shoot on DV.
Ever.
It basically looks like ****. The edges will be crap due to the limited color sampling of the compression in DV Cameras.
I have made that mistake once, when shooting a green screen for a website. Not even then was DV good enough.

Also use Shake for the keying if you can.
Its has many more options for tweaking and getting it right than FCP or After Effects.



Johan Polhem
Motion Graphics
www.johanpolhem.com

My own personal Green / Blue / Magentascreen rule of thumb:



EVEN LIGHTING (no wrinkles / shadows in the greenscreen bkgd). The backlight is VERY important to separate your subject from the bkgd. I know shooters that have been in this business for 15 years + that still can't light a flippin' greenscreen. Do it right - from the start.

- Joey



Post Edited (06-26-06 06:28)

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