Tips for Bluescreening???

kameronj wrote on 5/10/2003, 8:02 PM

I'm moving on to bluescreening. My first couple of attempts failed miserably. (For those who have already seen my X-Man spoof....the background was suppose to bluescreen out but didn't quite make it. Maybe in the DVD release).

So I am at the point now I figured out that a bedsheet won't do the trick!! Now I have a nice posterboard (dark blue) and did a shot - and it turned out OK. It sitll got a little fuzzy around the edges.

I had to monkey with the color correction first, played with the contrast/lighting, then applied the Chroma key and it was alright. But the subject kept getting transparent.

Then I figured it's the lights. I'm not using enoug lights to light the bluescreen evenly that is why I get patches.

Then I figured I can't have the subject too close to the bluescreen - don't want to drop shadows on the green too much.

Got a good 30 second shot - and then used the 3D plug in from Stash (the man) and cropped the subject top, righ, bottom and left - then keyframe panned the subject moving from one side of the screen and back and such. "That turned out pretty good. A lot of work for a 30 test (that I still have some holes in) 0 = but not bad.

It's called "Take Me Out To The Ball Game" if you are interested to see it. It will be on my website by tomorrow (am building the page for it right now and comrpessing it smalll enough to stream gooder).

But the reason I'm writing for help is I'm getting bigger and bigger ideas to use bluescreen techiques with and I want to get done with all my testing before I have to go into production. Or at least know all the tools I have to work with when I go into production (Shoot, edit, post production, cast party, cast party gets too wild and end up at night court pleading not guilty and adding the fact that I don't even like sheep!)

That's where you good people come in. I'm looking for good ideas, tips, etc about making and using a good Bluescreen method to shoot with.

Is it still called a bluescreen if I'm using green?

But I digress.

Really, what I'm hoping you all could do is get me down a good path of knowledge sharing - offer some advise on the lighting....tellme to use blue rather than green...(Can we use Orange?)

Thanks

Comments

Chanimal wrote on 5/10/2003, 8:28 PM

I have used multiple colors for the "bluescreen." I prefer a darker green--since it must be a color that is not used by the talent. I typically tape a large flat green sheet to the front of my 62" TV and put two shop lights (the $49 each/1,000 watts each) about 20 feet away at 45 degree angles, about 6' high. I then have a very even background to shoot in front of. I did multiple interviews and a commercial in front of my make shift bluescreen and it was very hard to see any lines at all. I sometimes put a low watt yellow light above and behind the person to counter any remaining green. Videomaker magazine has several good ideas to use.

In addition, VicMilt in this forum has a lot of experience with bluescreen studios.

kameronj wrote on 5/11/2003, 9:07 AM

Kewlness.

So I guessed right - it pretty much has to do with the lights? (Hey, that rhymed!!)

mikkie wrote on 5/11/2003, 9:24 AM

If it helps, they sell the paint for bluescreen/greenscreen work - *might* have some better, constant color characteristics, or I suppose it could be a bit of hype.

I'd also imagine that the color of lighting might have an effect... Logically anyway, if you had a flood or three, but some other source crept in that didn't match the color temp of the floods, your camera might see different shades of blue or green.

FWIW, not hard to kludge together a sort of softbox setup or two to light the background and get rid of shadows - While a bit fragile for everyday use, I've used window/door screen frames (sold in kits you cut to size), sheet fabric, and those clamps you get from the office supply for stacks of papers, or even the big plastic ones for bags of chips.

surfnturk wrote on 5/11/2003, 10:00 AM

I read a SPOT (DSE) tutorial regarding tips for bluescreen. DSE has moved away from the Creative Cow and gone to DMN forums.com so I am not sure where the tut is any more.

I found a thread regarding green screens.

Search on DMN for "Tip of the Day- green screens/Keying"

http://www.dmnforums.com/htm/homeset.htm

kameronj wrote on 5/11/2003, 10:50 AM

I read a SPOT (DSE) tutorial regarding tips for bluescreen. DSE has moved away from the Creative Cow and gone to DMN forums.com so I am not sure where the tut is any more.

Kewlness!!!

You all are the best!!

vicmilt wrote on 5/11/2003, 11:43 AM

The most critical part of "blue screening" is the back ground. It must be flat and evenly lit, with lots of light on it. Too little light will introduce noise and it will be hard to key out.
Any color will work, so don't get too upset, but bright green is generally accepted as the best for DV key work.
Keep your subject as far away from the background as is practical. On a professional set we generally use 20 to 30 feet or more - but the background is 20 feet high and 60 feet wide! Don't panic. I've done huge amounts of key work with a 6 foot wide background.
If you're going to do a lot of this kind of work, look for professionally produced key backgrounds - you can get rolls of paper (which will get ruined eventually) for $20 to $40 and fabric backgrounds on sprung frames for under $200. A smooth flat surface really helps the whole issue. I've seen (and been amazed by) Chanimal's green sheet key work - it's proof that ingenuity and hard work can make great results.
Use the long end of the lens (telephoto) to make the background as large as possible while putting as much distance as possible between the subject and the background.

Background spill kills good keys. So keep a good distance away.

Light the subject to the same luminance as the background, but it does NOT have to be flat lit. I like to use a nice hard backlight on the subject for more separation.
Try to match the lighting to the background that you will be keying into.

As Chanimal stated two large lights at about 45 degrees to light the green background generally will work fine. They are a separate situation from the foreground.
For "small stuff" I have painted a 4x8 piece of masonite with bright green paint, and it worked perfectly.
You will not get the kind of keys from (4:1:1 DV plus a $3,000 camera plus Vegas that you will get from a $85.000 4:2:2 DigiBetaSP and a $125,000 4:4:4 Ultimatte. But what you get should still be pretty damn good. But don't expect perfection.

Also, vary the background that you are using in the composite itself. Often by choosing a different background, you will be able to hide the key problems.

I have done many DV keys professionally and all concerned were happy. But I would not attempt a Star Wars level project with this semi-limited technology.

If you are a professional attempting keys, you must tell your client that good keys are possible, (they definitely are), and great keys cost money - period!

kameronj wrote on 5/11/2003, 12:53 PM

Vicmilt....thanks for the indepth reply. I did a good deal of research on the subject - and it pretty much keeps coming back to lights. Since I'm just "testing" the method now in my little backroom "studio" the lighting won't be that difficult to do and I think I can start to get a really good real world feel for what larger projects are going to take.

The testing that I have done so far turned out pretty okay - with the exceptions of the lights and the shadow. In the darker areas I had a lot of bleed through - and since I wasn't that far away from the green - when it did look good for the background - the subject kept getting transparent.

So a little playing around with the lights - and color correction (if need be) seems to be my path.

Thanks again.