Blue/Green Screen Thread

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DEDFX
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Blue/Green Screen Thread

Post by DEDFX »

Hopefully this thread will get large and turn into a sticky, maybe put some of your bluescreen/greenscreen footage up, talk about it, ask questions, etc.

I'll start off with a question, Should I buy bluescreen or greenscreen material? I've heard many mixed reviews and heard that blue is best for people (no blue in skin) and computers can pick it up easier, whereas green is easy for cameras to pick up, easier to light, but its bad because sometimes you can see that green glow on the edge of your subject being filmed.

Cany anyone help me here?
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RE: Blue/Green Screen Thread

Post by rhys »

The glow can happen with either, make sure u light the person and the screen seperately. Also use a good keyer. Blue is easy to find, but it cuts off jeans and really blue eyes, etc. People dont often wear bright green. Id go with green, but there both pretty much the same.
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RE: Blue/Green Screen Thread

Post by aaronv2 »

why do we need to tell people what they can reserach themselves?

http://en.wikipedia.org/wiki/Bluescreen

what about google?

Generally the different color materials are used to compliment whats being filmed.... green is best for human skin because there is some blue in it.

ive even seen red screen used to matte out grass.
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Post by DEDFX »

I've been researching for a few days now and have found different "research" on chroma keying. I thought since this is a movie making forum that I could talk to a person I'd know and get answers from real movie makers...?
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Post by aaronv2 »

theres a difference between real film makers and indie film makers. ala this place. and when you see indie films with bluescreen how high quality is it? Not Very.

There is so much to cover in this area it seems difficult to start explaining. You need to understand that there are so many steps to getting the footage just right. So whatever here we go.

A good screen is a thing to think about logically really. You need a bright even color that is good in most situations eg not reflective. Second it needs to spread light very well.
This is why most companies use material. A quick GOOOGLE! turns up this site.
http://cinemasupplies.stores.yahoo.net/chromkeyfab.html
This just shows you how desperate people are in regards to the price of their screen.
So if you have a permanent wall there is even paint there.

Anyway thats the high end. you can goto a fabric store and find something just as good. And back it with curtain material to get rid of the transparency in the fabric and also punch the color out more.

Besides thats only half the job. The tricky part is how do you light it evenly outdoors? What do you do to get peoples shadows not to show up?
You need to light (with more than one keep in mind) your screen seperate from your actors. So it needs to be pretty big... why? so you can take it far away. If you also use depth of field in your shot it will blur the screen removing the blotches but keeping your subject crystal clear.

Anyway once you have done all that and filmed it theres still the job of compositing it properly. You need to take into account that if your using DV footage there is alot of artifacts in the video which ultimately will affect your matte.
I use to my liking a mixture of filters to clean my matte. However others like to use filters to blur the channels to improve the quality.
http://www.joesfilters.com/joes_channel_blur

Okay anyway after considering the DV footage you have to consider how you want to key your footage. what filters to use etc. Like i said at the start of this there is so many ways to go...
Inner Outer Technique
http://www.creativemac.com/2003/01_jan/ ... terkey.htm
I mean a simple google Compositing Green Screen with your compositing software would bring up heaps of ways to do it.

Personally i like cleaning the matte instead of improoving the filters. Levels and brightness contrast can do amazing things.

This isnt even the half of it there are things to consider like garbage mattes and all the things you will pick up researching yourself and finding your own technique. GOOGLE IS YOUR FRIEND
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Post by aaronv2 »

can we make stickys for other subjects i just want some lightsaber threads and etc so i never have to spew up the same info over and over again
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Post by rhys »

can we make stickys for other subjects i just want some lightsaber threads and etc so i never have to spew up the same info over and over again
LOL! YES! PLEASE FOR THE LOVE OF THE HILLBILLIES!
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Post by DEDFX »

thanks for the info aaron

as for the lightsaber thread I'll get right in that.
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Post by madcowmovies »

Light sabers is how me and my Brosephs got started in making movies.

All the lightsabers/star wars stuff you need is right here
http://theforce.net/fanfilms/tutorials.asp

The one I used while learning was Ryan W's AE Tutorial.
http://theforce.net/fanfilms/postproduc ... orials.asp

theres a lot more as well. Also check the fan film forums, I used to frequent them, nice folks there.
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Post by DEDFX »

Heres my first test, I need light on the right side.

<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/Ep-aaei-G-w"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/Ep-aaei-G-w" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>
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Post by aaronv2 »

next lesson... color correction, you need to fix that spill and equalize your plate and bg elements. also that shadow needs to be opaque... and maybe cut down on the feathering so much you look a little blurry around the edges. we used to chat on msn rite? i forget but i think you used to do backflips and stuff too lol
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Post by DEDFX »

I'm learning Final Cut Pro which is much different from Premiere so it will be in good time since I get good with it. The Green Screen is harder to do in Final Cut but it's probably because I'm unexperienced.

If you're talking to me Aaron It could have been me but I've never done backflips or w/e.
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Post by rhys »

Heres my first test, I need light on the right side.
U can notice the green in your shadow, use keylight, it will look alot more realistic, and u wont have to be all smart like aaron.
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Post by MasterMike »

I think people need to realise that a chromakey is never a way to get round the work completely. Even in a professional sense, there's almost always some manual work to be done.
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Post by DEDFX »

Chromakey works for colors other than green or blue which is why some people use it. I used it in my test because it wasn't pure green and didn't work with the greenscreen filter.
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Post by kg9491 »

I just painted a green screen in my basement. I got the color combo from detonation films. anyway, the lighting is bad in my basement. What techniques should I use for proper lighting, and are there any special lights I need to buy?
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Post by kene555 »

Image

http://www.lowel.com/edu/lesson_green_screen.html

Always have a few lights in front at angles to properly light the actor, and to rid the greenscreen of shadows. Also, a keylight behind the actor is needed, in order to ensure that they stand out from the green. Point the keylight at the actor's back, so there is a bit of a glow from the light around them.

I had a similar question here

http://www.sticktowhatyouknow.com/U18/index.php?tid=37
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