View Full Version : What size green screen?


James Duffy
October 10th, 2007, 07:03 PM
I'm looking to do some green screening, but I've never approached this seriously before. The screens from eefx (http://eefx.com/eefx2/store/chroma_key_greenscreen_bk.html) look great, but I'm unsure how large a screen I'll need. Most of my shots will be medium shots or close ups, but I want an establishing shot that includes the subject's entire body. How large of a screen do I need for a shot like this, accounting for the necessary distance between the subject and the background to avoid green spill? I've heard that 10 feet is the minimum distance you need between the subject and screen -- do I need to have 10 feet of screen on the floor which he'll be standing on, and another 8 feet or so of vertical height? Or can I get away with something smaller, say a 10'x10' and have him not standing on the fabric?

Thanks.

Michael Nistler
October 11th, 2007, 03:00 AM
Hi James,

While 10 feet (spacing from subject to greenscreen) sounds nice, it's certainly not a requirement. You'll see many cut the distance down to 4 feet. Of course, there a several variables to consider (for instance Serious Magic Ultra) provides lots of post production tweaks to pull a good key.

Good luck, Michael

Nathan Quattrini
October 11th, 2007, 08:44 AM
serious magic ultra and adobe ultra are the same? Ultra now comes with the Premium Package CS3....but is it the same program? I also want to do some green screening and have a big wall at work I may be able to paint...looking for the same info

Michael Nistler
October 11th, 2007, 10:02 AM
Hi Nathan,

Yes, Adobe acquired all of Serious Magic's assets one year ago, including Ultra:

http://www.hardwaregeeks.com/comments.php?shownews=4382

Aside from their bulletin board forum, you'll find most Serious Magic links are now redirected to Adobe webpages.

Regards, Michael

James Duffy
October 11th, 2007, 02:10 PM
Hi James,

While 10 feet (spacing from subject to greenscreen) sounds nice, it's certainly not a requirement. You'll see many cut the distance down to 4 feet. Of course, there a several variables to consider (for instance Serious Magic Ultra) provides lots of post production tweaks to pull a good key.

Good luck, Michael

I do have Ultra... How would you avoid edge-bleed filming that close to the screen? A really strong hair-light? Or is Ultra good enough that you don't need to worry about pouring a lot of light onto your screen?

Michael Nistler
October 11th, 2007, 04:14 PM
Hi James,

There's several adjustments that relate to this topic. I highly recommend investing $50 and learning all about the Ultra settings on their instructional DVD - it's a great product but to the novice user, it's somewhat non-intuitive and tricky to get everything tweaked for situations as you've described.

http://www.4videoequipment.com/video/store2/Scripts/prodView.asp?idproduct=2856&E=Serious+Magic-Ultimate+Ultra+Master+Series+Training+DVD+for+Windows+XP+or+2000

Good luck, Michael

Emre Safak
October 11th, 2007, 08:07 PM
The separation you need depends to some extent on what format you are shooting on. Color-subsampled video formats such as DV require more care, and hence distance.

James Duffy
October 13th, 2007, 01:58 PM
The separation you need depends to some extent on what format you are shooting on. Color-subsampled video formats such as DV require more care, and hence distance.

Sorry -- the format is HDV, on an XH-A1.

Dean Sensui
October 17th, 2007, 12:58 PM
I have a 5x10 for headshots and a 10x20 for full-length.

This week, the 10x20 wasn't enough. It involved someone running up a porch where the person was inserted into the shot. That meant a scaled set to match the porch dimensions. Due to time constraints we had to use what was available. Otherwise we should have built a partial set and/or arranged to get enough fabric.

I'm also using EEFX green screen. It's really great stuff.

Using Primatte in After Effects to do the compositing. It's not the easiest software to use but when applied well it does a great job.

I also shoot in DVCProHD which has 4:2:2 color sampling. It makes a big difference around the edges and for fine detail. For problems inherent in DV and HDV, Primatte has an artifact removal feature that works very well. I helped clean up a spot shot on DV here against green screen for Taco Bell.

Not the best source material. But the results came out a lot smoother than I'd expected. Ironically, the graphics inserted in the background was mostly green anyway!