Shooting Green Screen for Matte only

gkantziper

gkantziper

Esteemed Member
Has anyone shot green screen with the HVX for matte only in the final product like the old iPod commercials? I will shoot 1080i/30P and will shoot a slightly faster than normal shutter speed because the talent will be dancing to reduce motion blur. Any thoughts on what scene file to use for the best key? I have been using "stock" Cine V for most everything else and have had good results. I realize lighting the green screen evenly is important but is lighting the talent that critical? Anybody have experience with this?
 
Lighting the talent is important. Make certain, of course, that it doesn't spill onto the screen or isn't too hot.
 
i just shot a video like this. if you want ultra-sharp clean mattes, shoot at a high shutter speed. i shot at 1/250 and it is razor sharp. if you want motion blur later on, add it in post.

i also cranked all of my detail settings to +7. this will cause some debate but the footage speaks for itself.

don't worry too much about your screen being a perfect solid shade of green throughout the frame. any good keying software will handle a nice range of green in any given shot. we put tracking dots up everywhere that were a good 2 stops lighter than the rest of the screen and no problems keying them out. the biggest challenge is keeping the green spill off of your talent. you don't want to key out part of someone's face because of spill. it can be hard to tell that it's happening. when you are staring at a big green wall, a little spill on someone is hard to detect but it will bite you in the ass later. throw duvetyne up where ever you can and throw it on the ground if possible. this helps a lot.
 
If you happen to have DV Rack or Adobe OnLocation you can use the Spectra 60 to pick pixels off the edge of talent to check for spill. See the Adobe documentation if you're not sure how to use it. The waveform monitor is also great for checking the level and for how even the lighting is on your greenscreen. It's a great product for this type of studio work.

Don't forget some backlight. Also, you can add a light magenta color to the backlight to counteract spill. Just don't over do it or it will look red in the finished product.

When you pull your key, best to do multiple keys by doing a garbage matte first and then successive keys to get the best look. You can even use different keyers for different parts. I use Boris Red, Ultra II, and the keyer right in Vegas. They each have their strengths for different projects as well.

One last thing, watch shiny objects on your talent like belt buckles, watches, etc... they tend to pick up spill and become transparent very easily.

Good luck!

Mark
www.newmediadevcorp.com
 
I've shot a lot of that, I found it really easy to do, What I did was: I lit the Greenscreen turned off the lights in the room and put them in front of the lights so they were silhouetted by the green screen, then later in post you can invert or colorize the totally black figures.
 
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