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View Full Version : Blue/Greenscreen -- I need SPACE!!!



SamuraiSlayer
02-23-2004, 08:21 PM
Hello and Welcome to SamuraiSlayer's "Thread-'o-Chaos"!!!

Im using LightWave... and trying to use a blue wall for bluescreen effects. Oh, and a DV camera. I know this is a HORRIBLE combination, but its ALL I GOT!!!! Well... sorta... maybe YOU can help me...

I have a basement, it has junk in it. I want to attach a person to one or more cables and hang them (that dont sound right but... dont take it the wrong way... :p) from the ceiling. The basement is probably the only choice because the ceilings on the upper levels are weak. So I guess I could use the basement... got any ideas?

My second problem is that the walls are kinda unpaintable. I could paint something (blue or green) and put it against the wall... that might work. What should it be? What paint should I use? What color? Blue? Green? What shade of blue/green? Semi-Gloss? (prolly not) The paint has to be cheap because I haven't yet won the lottery (I will I tell you, I will!!!! some day!!!)

If my tired little mind can stir up any more idiotic questions i'll be sure to post them because... if you can understand my mind, then you'll understand EVERYTHING, and you can be the president of Libya... Did you know their flag is ALL green? That's it. Just GREEN. No designs or anything.

Well... there ya go, my 3 cents worth. :p :p

Dave Davies
02-24-2004, 11:19 AM
Hi,

Which keying software are you using? DV doesn't normally key well, because the 5:1 compression makes the solid background color look banded. I hear Ultimatte has a product that takes care of this, but I haven't seen it. I use Ultimatte and analog video, and have no problems.

Yes, you can paint something, like a sheet of plywood, and attach it to a wall. Almost any colour will work, as long as it doesn't exist in the foreground. Blue has been used traditionally, but green is now common. It depends on your scene - if your talent is wearing a blue shirt, denims, and has bright blue eyes, you'll want to us a greenscreen. If you're shooting a green frog, use blue.

You can buy special chroma paints from stage suppliers. You can also use bizarre shades of whatever color you choose - the idea is that it is as different as possible from the forground, so the software can tell where the chenges are. The better the cotnrast, be the better the key.

More important though, is the lighting - good keying is ALL about lighting. The background must be as evenly lit as possible.

The foreground needs to be lit to match the keyed-in background - ie: if the sun is coming over the left shoulder, that's how you have to light the foreground. With a low basement ceiling, that might be tough to do.

That's a very simplified explanation, but hopefully, it'll put you on the right track.

munky
02-24-2004, 12:07 PM
I'd suggest some insurance, in fact quite a lot of it.

I don't want to put a dampener on your idea's but paint and lighting aside you really need to make sure that wherever you shoot and what you are doing is safe for you and in your case whoever is going to be hanging from your wires. A small studio/cellar filled with lights with people hanging around on wires isn't the best solution. You really need to find a proper studio with a decent lighting rig that you can hang stuff (lights and people) off. It might be worth seeing if there is a local film school that might be able to help. Also check out your local climbing school/club as they would be able to advise on harnesses and breaking strengths, although the last time I flew some people around I used a specialist flying wire team.
Obviously you have no cash but do be really carefull and research this thoroughly before you shoot.
Also you can hire blue screen drapes (big curtains) if you want to save the cost of paint and plywood, you'll just need a frame to hang them off.

sorry to sound like DAD

regards


paul

prospector
02-24-2004, 02:15 PM
Now that munky has given the mandatory legal mumbo-jumbo:D

On to the FUN!

I too couldn't paint a wall so I did the next best thing.
Got 2 sheets of the board that looks like pegboard (really hard fiber board with smooth surface), without the holes.

going sideways I went with half board (2X8 feet) and full board (4X8 Feet), and putting the larger on top I got a 6X8 wall and painted blue (same color as Blue M&M), no shine at all.

But found that a neon green is much better and easier to remove.

So that got my wall.

As for hanging people.
I did a square platform of 4 feet deep by 10 foot long (to fit above the greenscree).

So I got 4" X 4" posts on each corner 8 feet tall.
then around the top I have 2 2X4s running the lenght and 2 4X4s across the depth.

BUt I put a water pipr 1/4" black iron running across top for the full 10 foot lenght.
And run a pully that fits to pipe with wires hanging down to hook to people.
Now I can make them fly across screen (as soon as they quit screaming;) )

Now you say you can make them fly with greenscreen just by making the background move, which is true as far as that goes,

But I can have a static actor interacting with a moving actor.
no post composition and no retakes because someone isn't looking directly at the other.

You've seen it before,

Everyone looking at monster or something go by and thier heads are either behind or ahead of the effect they are watching.

Just some hints:)

SamuraiSlayer
02-24-2004, 02:53 PM
thx, prospector, for cheering me up because after i read munky's post i was about to stab myself with a pencil... just playin! :p

so was ur square platform inside or outside? if inside, how tall was the ceiling?

thx guyz for the help :)

prospector
02-24-2004, 04:40 PM
Inside
I got an 8 ft ceiling.
But I made it the same size as the wall so the actor could be off the greenscreen till it was time for then to come into view, which is why I built it 10 feet and greenscreen is 8 foot wide.

Now I'm NOT saying to disreguard what munky said, but that part ISN'T the FUN stuff, but it is necessary, unless you hire people who don't mind doing things like hanging around, and won't sue if they get scratched.

munky
02-25-2004, 05:19 AM
Hello chaps

on a less cautious note check out www.dvgarage.com/ for their dvmatte pro plug in.
Also for future reference go to www.reflectmedia.com and see their camera keying solution.


regards

paul

WizCraker
02-25-2004, 11:20 AM
Or you can get the materials from Filmtools.com

The direct page for Chroma key fabric is below.

http://shop.store.yahoo.com/cinemasupplies/chromkeyfab.html

John Melvin
02-25-2004, 11:33 AM
I built several "Greg O Flo Lights". With a white wall and ceiling you do not need any green paint or screen. I thought you might but if you can get your subject far enough from the wall so that the subject lighting does not wash out the lighting from the Greg O Flos then it will key perectly in VT3 and really well in DF using Ultimatte Advantedge.

I input this image into BOB using the monitor out from a JVC KY90 camera and got a great key. The key that you would get from a recorded image into VT3 with SDI should be even better.

FWIW

John

sbrandt
02-26-2004, 01:41 AM
...you can do what I did.
Pop a few bucks for ULTRA Key and work with chromakey as if your DV camera was 4:4:4

I've had mine a week and a half now, and it does everthing they claim it will.

I also read somewhere, and I don't know how accurate it is, maybe someone can verify it... that the people who run Serious Magic are ex-NewTek brainoids.

http://www.seriousmagic.com/ukoverview.cfm

John Melvin
02-26-2004, 09:32 AM
How does Ultra Key integrate with VT3.

Thanks

John

sbrandt
02-26-2004, 01:51 PM
I was responding to SamuraiSlayer's original post that said:

"Im using LightWave... and trying to use a blue wall for bluescreen effects. Oh, and a DV camera. I know this is a HORRIBLE combination, but its ALL I GOT!!!! Well... sorta... maybe YOU can help me..."

The only application I know of that will enhance the useability of DV in chromakeying and do what it claims, is UltraKey.

It also works with blue. But so far, I've used it with the FlexDrop2 green screen (works perfect) and a bolt of Kelly-Green cloth that's a couple of shades off the FlexDrop green but is as close as we could find at WalMart. (it works perfect too)

SO... I see no reason, using UltraKey, that keying against a green (or blue) painted wall will not work. And, once again, because UltraKey is so forgiving with DV camera colorspace, it's not necessary that the Green (or blue) be exactly the right shade or the lighting be of Hollywood quality.

It's a stand-alone application but I can import anything from TEd or Lightwave in as a background or forground.
It imports:
AVI24-bit Uncompressed
AVI32-bit Uncompressed with Alpha
DV AVI Type 1 and Type 2
.PNG, .JPG, .BMP, .GIF, .TGA - 32 bit .PNG, .TGA