guerilla chromakey experiment

ok, i've been playing with what i'll call "guerilla greenscreen" setups. by this i mean setups where you'd need to set up a chromakey shoot with not a lot of room, no crew and not a lot of setup time.

admittedly im not a big-time chromakey pro. ive done maybe a half dozen in the traditional method and have only had 3 days of work with the reflecmedia. but i do have a pretty solid grasp of the basics.

i used 2 setups:
1. reflecmedia (led lens light + reflective screen material)
2. traditional cloth/foambacked green backdrop + 2, 4' kinoflo fluorescent (green tubes) fixtures, 3 feet left and right of the screen

both clips were shot under the same lights and the same camera settings. camera was my hvx200 dvcpro HD 720p, cine-v settings (slightly modified)

subject lighting is keylight, sidelight and one room-fill

room was a 14' x14' office. backdrop was in one corner of the room. camera was in far opposite corner, roughly 12' from screen - NOT AN OPTIMUM LOCATION (hence the "guerilla" definition)

keying was done in FCP using dvmattepro 1.5

the thing ive found most hard to key over the years is detail movements, so we had each subject move around a good bit and doing a lot of hand movement - sorta "chicken-dance meets the hula"

below are two links to the sample clips: - each clip is set up to show first the final key, second the source clip and third, the clip keyed to black so you can best see the chroma details.

clips are right off the p2 card. not corrected and keyed quickly (-3min of setup)

1. reflecmedia
[understandinc.com]

2. traditional
[understandinc.com]

here is what ive found:

1. reflecmedia. the big plus is that you dont need to light the screen. lighting is provided by the led lens ring. there are pros and cons to this;
PROS
- you dont need extra lights on set and thus you keep the temperature lower.
- setup is ultra quick and easy. two pieces, a collapseable 8' backdrop and the led ring. [in theory] - you can do it in a smaller room - though actual mileage to this thery may vary...
- not a ton of spill.
CONS
- being directly in front of the subject, the light ring casts a direct shadow around the subject (as you'll see in the clip) making it hard to pull a smooth key. this can be slightly remedied by moving the subject farther from the screen, but from what ive seen, it doesnt remove the shadow just make sit less prevalent. this also kinda defeats the one of the selling points of the reflecmedia setup as you are [supposed to] be able to put the subject closer to the screen for use in smaller rooms...??? whatever.
- chroma value is kinda limited by the intensity of the ring light.
- cant be used with traditional teleprompters
- the backdrop is UBER EXPENSIVE for its size and is kinda delicate and can fairly easily be RUINED

2. traditional method. VERY EVEN CHROMA! i love this setup! as long as you have the room and the time, its pretty much bulletproof.
PROS
- EVEN LIGHT and EASY TO pull a good key.
- moderate temperature increase (if you use fluorescents).
- very robust and hearty gear - no need to baby the kit.
- LOOKS GREAT!
CONS -
LOTS of onset gear required (BIG lights, heavy stands, ballasts, heavy cables)
- need lights for both the screen and subject.
- need lots of room. MINIMUM of 8 feet from screen to subject.

traditional method is about a grand more than a reflec setup. the reflecmedia kit (light ring, adapter, light control, popup screen and soft case) is $2800 and a 2 light kino (with hard case) is $2800 then add $300ish for an 8x8 green backdrop and $250 for a backdrop stand and another $500 for two c-stands

if i had to chose one or the other. id go traditional when at all possible.

Very nice demonstration, Wayne.

Great stuff Wayne

You ought to look into Veescope Live. Right now its a free beta. Takes guess work out of the equation.

[www.dvdxdv.com]

Michael Horton
-------------------

yeah mike, i downloaded that a couple days ago. but it had expired before i even downloaded it : (

the dvdxdv site is totally jacked up now. demo is expired, all buttons take you to the same page, their table cells are all missaligned - wonder what they are doing with it?

Is that you wayne? Are you bald?


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
[itunes.apple.com]

ha! yep. how'd you know that was me? you must read lips...

Very Good Demo.


It would be very interesting to have someone key the same clip in Shake, FCP and After Effects to compare results.

Johan Polhem
Motion Graphics
www.johanpolhem.com