Settings for green screen

[BigBill]

Guys,

I've shot green screen footage several times and I haven't figured out the best settings on my DVX-100. (I have the original model)

Any quick advice you can give me? I'm mostly concerned with whether it's 24pa or 24p and why.

Thanks guys

[Alex H.]

24p and 24pa are pretty much the same. The only difference is how the pull-down is added in anticipation of editing in 29.97 or 23.98. I'd say go with 24pa so that you don't have any frames that cause you problems. But DV is DV, progressive or not. The biggest factors are in good and even lighting.

[Steve2012]

The biggest factors are in good and even lighting.

Yup, that and a super tight junk matte in after effects Keylight will get you very realistic keys!

[BigBill]

I'd say go with 24pa so that you don't have any frames that cause you problems.

I believe the editor plans to edit at 30fps, so wouldn't 24p be better?

Also, what do you mean by "frames that cause you problems"?

Thanks for the advice!

[Jaimebailon]

if the editor is going to edit in 30 then there is no question shoot 24p(which is not true progressive) or why not shoot 30p

[NC17z]

I have a better suggestion for ya.... Make sure your green screen is lit consistently and make sure your subject is half the distance from the green screen and the camera. Meaning 16 feet away is your camera and 8 feet away from your camera is your subject.
The exposure of your subject should be twice/double of what your green screen should be.
Use the marker setting to test the expouser... point it at the green screen, it should be at 40 to 50 %... and your subject should be exposed/lit up with light at about 80-90 %...
These settings work great for green screen... and definitely use a rim/hair light on the subject...

[BigBill]

Use the marker setting to test the expouser... point it at the green screen, it should be at 40 to 50 %... and your subject should be exposed/lit up with light at about 80-90 %....

Sorry for my ignorance, but what is the marker setting?

I always thought that the green screen should be lit better than the subject, who should also be well lit, and with our lack of lights, I planned to do it that way, but I'll definitely try this out.

Thanks!

[NC17z]

When you open up your LCD and inside is a Zebra Button... Push the Zebra Button until it says MARKER ON... wait a second or two and then in the left hand corner of your LCD you will see a Two Digit Percentage. This is where your exposure level is. Light up your green screen (evenly as possible)... how can you tell if it is evenly lit. Use the marker percentage pan and scan all over the green screen. There will be a small box in the center of the LCD that you aim. Try it out on the other side of the room, aim it in a dark corner and then aim it at a light, you'll see what I'm talking about. You'll know if your too hot or not. Try to keep the green screen as even as possible. This makes for better keying in post. Then introduce the subject and light him accordingly to the content your creating however, try and make the subject brighter (lit more) (by 30 to 40% more) then the green screen. This gives you the right kind of contrast between the two. I've been using this method for some time now and it has never let me down. My keying ends perfect.

[BigBill]

Thanks guys! The advice was invaluable. I'm going to try out all your tips for the shoot.

[NoNoob]

Lighting and separation are the key to a good green screen production.

The green screen material should be flat and non-reflective.
*Wal-Mart has this excellent fabric that is great- and cheap. I think they make moo-moos out of it.

It should be taut and smooth so the light falling on it is absolutely even.
From one side to the other and up and down- no more than one ƒ-stop deviation in level.

There's no 'rule of thumb' for distances- because the math just doesn't work in some instances.
I've done adequate green screen shots in small offices, without moving anything to accommodate 'doubling'. OH- it'd be great if you could, but don't depend solely on having double the distance from subject to screen.
Lighting is the utmost important consideration.

Most important factor- ESPECIALLY working in 4:1:1 color space?
Sufficient rim light around the subjects to define the edge between them (in the key light) and the background material.
I use straw gels on small lamps at an off angle just to pull this off.
It works great in the matting process.

Laying down a good choker matte beforehand is beneficial.
But "Keylight" is just awesome!
Jaw dropping excellence, and highly recommended.
[there are other plug-in and stand alone software packages that provide superb results, but can be quite costly. It this is a once in a while thing, rely on Keylight to do the job.]

Hair- especially boufy big hair with lots of curls and spikes- is the BANE of separation.
It'll kill a good matte job.
4:1:1 is not deep or robust enough to handle the process easily, and you give up quality for style with some outfits and hair.
Darker clothes (and gosh forbid, no WHITE shirts!) work well, and good makeup on the talent is very important.

Action should be limited to small, controlled movement.
I did a como with six actors in costume who had to be set on a moving BG of a tropical isle.
We did a test (in the studio*) and refined 'action' so that there was no lag in the key (revealing the key effect). *It's a good idea to have the ability to test your footage as you shoot- saves time and effort in the long run.

If your action is a cross or walk through- you'll have all kinds of headaches with the light levels unless on a perpendicular plane.
Say- crossing from screen right to left- on a straight line, all things should be equal; BUT, doing the same cross but at a 45°, the level can change dramatically (possibly ruining the shot).

Good planning and testing makes the grade.
After all, we're really faking out the system by doing this.
In some places green screen is probably agin the law....


good luck - and let's see some footage once you get it down!