Green screens Blue screens

ill-matic · #1 (**permalink**) 01-03-2004, 03:17 AM

Hi all i am a new member but very keen member.
I would like to change the background in a video and wanted to know the diffrence between green and blue screens.
I just came back from disneyland and in the one of the disney studios they recomended blue screens ??.
Also what could i use a realy cheap way with good effect I mean i have tryed a bed sheet and it did not work that well because of shadows.
Thanks all sorry to sound like a newbe

mrlipring · #2 (**permalink**) 01-04-2004, 02:29 PM

it's a bugger to do, apparently. it's something i've been looking into. Up until now, myself and the guys i work with haven't done any special effects at all. just pyro stuff, "real" sfx, as opposed to digital stuff, camera trickery etc. so we're planning on doing some bluescreening just to get a hang of it. i know in Glasgow we can rent a screen and the proper lighting from the G-mac. Apparently the lighting is what really clinches it. you need the screen to be VERY evenly lit.

Marc Peters · #3 (**permalink**) 01-04-2004, 02:42 PM

So when can we see some of your work

mrlipring · #4 (**permalink**) 01-04-2004, 03:18 PM

when it's done!

the first real thing i worked on is being edited now. i think all the video's done, it's just the stuff we didn't get sound for that's taking AAAGES. that, and the head honcho went and got himself a job over christmas, so it was put on hold.

i did a little sound, a little acting (god, i'm sure i was terrible) and a whole load of explosions and gunshots and stuff, so i'm looking forward to seeing the final product.

as for the bluescreening, the plan is to knock together a short of me fighting other mes, and getting bigger with every me i kill, until i'm towering over Glasgow city centre, godzilla style. It's not meant to be particularly original or good, it's just so we can learn some sfx, because we really haven't done anything like that before.

http://www.workshedfilms.com/

Is the website.

stevep · #5 (**permalink**) 01-13-2004, 09:06 PM

So whats the difference between blue & green screen?

watched minority report 'making of' the other day, sometimes they used blue screen and other times green screen.

Marc Peters · #6 (**permalink**) 01-13-2004, 09:29 PM

Well, that's a question that goes beyond my knowledge, however, this link difference between blue & green screen discusses the matter in great detail. Don't have time to read it all - and I'm sure it'll ask more questions than give answers

andy75 · #7 (**permalink**) 01-28-2004, 04:32 PM

blue or green, technically makes no difference. The key is lighting, the screen must be evenly lit (try 2 soft lights), then you need to separate the subject by means of back light. Bring the subject forward of the screen so when you light them they do not cast a shadow on the screen (you will need a bigger screen than you think); then you need to back light them. Two 3/4 back lights work the best,ie: behind the subject at about 45 degrees.

Snake · #8 (**permalink**) 02-02-2004, 11:32 AM

Well we have every thing, hug blue screen with proffesional lights and cams..we took the shoots but we still need a pro. editing program to change the damn blue screen, is there any one who can help to find a pro. program for changing and editting the blue screen so that we can replace it with a motion picture or a movie???

Thanks any way

SNAKE

Marc Peters · #9 (**permalink**) 02-02-2004, 12:19 PM

Premiere Pro does the trick. You place the "blue screened" shot in one of the superimpose layers, then drop in the "blue screen" video effect under the "keying" category into the clip. Then the blue areas of the shot become transparent and you can see "underneath" into the master track.

Easy as that

Belzibut · #10 (**permalink**) 02-29-2004, 07:20 PM

Hi Marc, I pretty much did what you wrote in the last post and it kinda works. I did my clip with a green background and when I add the green screen key effect it removes the green and change it to blue. I'm thinking that this blue is the transparency. Actually one thing I didn't do or not sure how to do and it's what your wrote: "shot in one of the superimpose layers".

But my question is: how do you change the transparency into a still picture. I have tried a few different thing but it doesn't seem to work. Perhaps you know the answer to my question.

Thank,

David