green screen help

[shadow of chaos]

i tested my greenscreen with just 2 worklights for now to see how it would come out.

i used the program wax to get rid of the green, or some of it.. but the problem is that if i go to far then i start to become invisible. I cant get rid of all the green, i see it bordered around me as a square but because the lights were low down on seats, most of it if not all of it cant be seen down the bottom.

i though this would have been easier, can somebody make it a little easier for me?

[Erik Bien]

soc,

There are a few basics to keep in mind:

1) Light your screen as evenly as possible. Hotspots make it harder to pull a key. Try using your in-camera zebras, not to set exposure, but to make sure the screen is all lit the same.

2) Light the talent separately from the screen. Any spill from your light onto the greenscreen will create shadows that will be difficult to key.

3) Distance is your friend, and wrinkles are your enemy. Stretch the screen as tight as possible, and try to have your performance area at least six feet in front of your screen -- green light reflecting back on the talent makes it tough to pull a key. If you just don't have enough room to get all the green spill off the talent, hit them with a little bit of backlight or rimlight with a magenta gel, to counter-act the green.

Hope that helps.

[shadow of chaos]

soc,

There are a few basics to keep in mind:

1) Light your screen as evenly as possible. Hotspots make it harder to pull a key. Try using your in-camera zebras, not to set exposure, but to make sure the screen is all lit the same.

2) Light the talent separately from the screen. Any spill from your light onto the greenscreen will create shadows that will be difficult to key.

3) Distance is your friend, and wrinkles are your enemy. Stretch the screen as tight as possible, and try to have your performance area at least six feet in front of your screen -- green light reflecting back on the talent makes it tough to pull a key. If you just don't have enough room to get all the green spill off the talent, hit them with a little bit of backlight or rimlight with a magenta gel, to counter-act the green.

Hope that helps.

i have 2 500W work lights, is that enough?

heat is not really an issue because i can put it up near the conservatory door and keep it open.

By the way, i also got 2 barn door kits for the work lights. Is that a mistake? or are barndoors purely for the talent?

[Erik Bien]

What will help the worklights more than barn doors is some diffusion: most of the halogen work lights create a very bright hot spot near the middle, falling off towards the edges. Shooting them through a big sheet of diffusion might help. The poor man's solution is a textured clear plastic shower curtain or an old white bedsheet stretched across some type of frame, but be sure you put a LOT of distance between those hot lights and any flammable/meltable diffusing material! Safer to buy the real thing: Lee 216, 250 or 251 or Rosco tough frost, half frost and opal (listed from most opaque to most transmissive).

[shadow of chaos]

What will help the worklights more than barn doors is some diffusion: most of the halogen work lights create a very bright hot spot near the middle, falling off towards the edges. Shooting them through a big sheet of diffusion might help. The poor man's solution is a textured clear plastic shower curtain or an old white bedsheet stretched across some type of frame, but be sure you put a LOT of distance between those hot lights and any flammable/meltable diffusing material! Safer to buy the real thing: Lee 216, 250 or 251 or Rosco tough frost, half frost and opal (listed from most opaque to most transmissive).

is there a not so poor mans way, which is alot easier to setup? :hv20-smilie51:

Shame there wasnt like some site that did certain stuff like a small kit on a budget but worked as well as the more expensive stuff.

[Erik Bien]

Shadow,

What a lot of folks use to illuminate smallish greenscreens is plain old flourescent shop lights, the kind you buy for twenty bucks at Home Depot to hang in your garage. "Cool White" bulbs look like doo-doo when used to illuminate people, but the 'green spike' in their spectrum that's so unflattering for skin won't pose a problem when all you're trying to light is a piece of green fabric.

Flos are a naturally soft, diffuse source, and they won't burn down your studio like halo work lights can! Hang a couple from the ceiling and angle them back towards the screen, use a couple on the floor propped up angled back towards the screen. The goal is not to light the hell out of the screen, just to get it lit as EVENLY as possible. Most cheapie 4-foot flos don't seem to "like" being installed vertically (sooner or later, most start to flicker when used upright), you might try the spiral-type bulbs in some "clip-light" reflectors if you need fill from the sides.

Those halo worklights can then be used to illuminate your talent, and the barndoors should be enough to keep any spill off the screen.

[stoop]

Shadow:

DJTV to the rescue. Simple green screen, explained:

http://www.digitaljuice.com/djtv/segment_detail.asp?sid=78&searchid=23724

Also, for the technology of chromakeying:

http://www.digitaljuice.com/djtv/segment_detail.asp?sid=95&searchid=23724

- Stoop

[Murrelet]

Thanks for those links stoop...vverrry interesting.....makes what Erik posted quite clear.

[shadow of chaos]

the green screen i have i believe is 12 x 9

i was hoping to move around quite a bit with that, should be big enough for what i want right?

[Erik Bien]

Hah; well that depends ... if you want to key out a 747, you might need more ... :hv20-smilie84:

Anytime I bring up post-production I plead for others to correct me, but generally speaking you just need enough green-screen to capture all the "edges" of whatever you're keying: in other words, if you want to key an actor into a shot with King Kong, the camera is likely to be quite a long way away from the actor, but as long as the camera sees him surrounded by green, you should be able to "extend" the green with garbage mattes before you composite him with Kong.

[zephyrnoid]

On the money advise and may I add two more?

4) With distance being your friend, try to apply green gels over your background lights. It not only evens the color more effectively but more closely matches the Key (out) spectrum.When using 3200/3400K hotlights you're introducing a lot of red (a near compliment of Green) filter that out first then add some green to match the background.
5) The use of "green" is no longer a rule when software is used to "key" to a color for removal. Use the color that is least dominant in the subject's edge. It might be blue or Purple or what have you. Just always add the filters over the (backdrop) lights to bring them into sync.
Green is the original 'cause so many stripped in backgrounds were outdoor scenes and it allegedly does not occur as much in the foreground subject.What with the green movement happening, every one will soon be wearing a lot of it !:hv20-smilie81:




soc,

There are a few basics to keep in mind:

1) Light your screen as evenly as possible. Hotspots make it harder to pull a key. Try using your in-camera zebras, not to set exposure, but to make sure the screen is all lit the same.

2) Light the talent separately from the screen. Any spill from your light onto the greenscreen will create shadows that will be difficult to key.

3) Distance is your friend, and wrinkles are your enemy. Stretch the screen as tight as possible, and try to have your performance area at least six feet in front of your screen -- green light reflecting back on the talent makes it tough to pull a key. If you just don't have enough room to get all the green spill off the talent, hit them with a little bit of backlight or rimlight with a magenta gel, to counter-act the green.

Hope that helps.