Chroma Keys in FCE Help

[Lutonian]

Can anyone assist me in using the chroma key effect/ blue&green screen effect in FCE? How do you insert the video thats going to take over the green screen area? Etc...

Im sure its similar in FCP, anyone know how to do this?

 

[RobDreugan]

I can only tell you how you'd do it in FCP.

Place the video that you wish to key on a line above the object you want keyed into the background.


So, your footage shot on a green screen would be on V2 for example. The still picture of New York, or whatever is on V1 in the background that is streched out for the duration of the video clip above it.

double click the V2 clip, and then go to effects > video filters > key > chroma keyer.

Once you see the tab come up on the viewer window, with the clip that once you dbl clicked was in the viewer, you should see a tab that says chroma keyer, after motion.

Go to that tab, select the visual button; You'll then see an eye dropper on the right, click on that, then click on the canvas window wherever on yer video you want to select the color you wish to key. You should then immediately see it disappear. You can play with the settings to adjust the color that it takes out, as it could take a larger range of color than just 1.

But that should get you started.

 

[Lutonian]

thanks im starting to get the basic idea of how this works, and im experimenting with the settings...

but what actual material do you suggest be used for the green objects being blanked out? Some type of green cloth, something that absorbs light, rather than reflect it?

 

[RobDreugan]

thanks im starting to get the basic idea of how this works, and im experimenting with the settings...

but what actual material do you suggest be used for the green objects being blanked out? Some type of green cloth, something that absorbs light, rather than reflect it?

Professionals use many different colors depending on the situtation or what people are wearing that's an absolute must. There's Red, White, Blue, Green. Those are typically the best to use.

With regards to material, there's lots of different routes. I've shot outdoors before and used pieces of green posterboard; Indoors I've painted a wall green, that's most similar to greens used in studios. The professional grade paint actually has a certain mixture that helps digitially to enchance the results, although I couldn't tell you exactly what. And yes you could use a cloth for it as well.

Here's the rule. As long as you have one solid color, that when lit is even across the entire area you can key it out. If there is any falloff, i.e. the center of the green screen in your frame is most green, and then it gradually fades to black on the sides, top etc... if you have any of that you will get pixelation. B/c then you don't have 1 color to key out, you have 1 color and shades of that color, which if dark enough can start to get the blacks on your subject.

Rule of thumb when yer doing this; if it's a case where you have to light someone and the lights can't be high enough to take all the shadow off the person, like a grid in a studio could, then you have to place the person at least 5-6 feet in front of the lit green screen to make sure there are no cast shadows.

To recap: Any solid color that is lit well will work. Falloff, or shadows on the green screen will damage the results you want. And you typically want to put your subject 5 - 6 feet in front of the screen so as to eliminate cast shadows. Light your wall, light your subject.

(If you look at my site down below, and go to the "show" link; Check out psychoquell, the person's head/shoulders i filmed was out doors using the sun to light both him and the green screen, a piece of green posterboard. Worked like a charm.)

Hope that helps.

 

[MILKBONE]

RobDreugan: you went over doin a chroma key for a still picture of something. is there ne way to do a chroma key over another video clip? or do u just do the same steps and insert a video clip where the still one would be?
thanx for ne help

 

[RobDreugan]

It's the exact same thing.

 

[Lutonian]

Im not sure if your familiar with this or not but........I was watching this 5 minute mini movie where in a few shots they had replaced the sky with a sky they had color enhanced (to make it look trippy&surreal). But there obviously wasnt a huge green screen floating in the sky. Is it possible in FCE/FCP to cut out part of a shot and add in a different one.

I believe they used Adobe After Effects, but is there a basic feature in FCP/FCE to add composite video effects.

 

[RobDreugan]

Im not sure if your familiar with this or not but........I was watching this 5 minute mini movie where in a few shots they had replaced the sky with a sky they had color enhanced (to make it look trippy&surreal). But there obviously wasnt a huge green screen floating in the sky. Is it possible in FCE/FCP to cut out part of a shot and add in a different one.

I believe they used Adobe After Effects, but is there a basic feature in FCP/FCE to add composite video effects.

Couple of things could have been done.

a) if the sky were one color the whole way down, they could have just keyed the sky out.
b)You could do something which takes considerably more time and effort called masking. Basically, you sit there and kinda like the quick mask tool in photoshop you create an area that you want to "delete" so to speak, and then have something else there. What's not fun about this ist that technically speaking each frame is different, therefore if u were to mask lots of movement yer going to sit there and mask every single frame.
c)You can create what's called a garbage matte in FCP; you can adjust what it cuts out kinda like a mask. Play with that some, you'll see what i mean.

I'm sure there could be some other methods of doing it, but I still don't know after effects half as well as I'd like.