Shooting bluescreen on RED-One MX

[Jake Bastian]

A bright screen can increase spill, and increased spill can corrupt edge detail. The cause of the bad edge details is spill, not brightness.

The answer isn't to dim the screen, but to control the spill. I unfortunately assumed you all understood this cause/effect and knew how to control spill.

It's not spill that I'm worried about but something closer to blooming. Similar to how you would use a lightwrap in compositing to produce a more realistic result an overly bright screen will 'shrink' your edges.
If it works for you though that's great but you won't catch me doing it any time soon.

 

[Eki Halkka]

Pull rank? lol "My show's bigger than yours" ha. It is rather silly, made me smile when you wrote it that way.

I'll be here all week, try the veal ;-)

I'll take it further though, if you have to choose between my idea of lighting the screen brightly and even lighting - always choose even lighting.

Agreed - and the same vice versa...

Well now you see some of the reason in my madness. That white shirt should be brighter than the screen ... so you can luma key it, and subtract that from the luma key of the chroma screen.

Or use some other combination of chroma and luma keys to build up a working matte.

Ah okay... in that case, i start to understand your point about luma key - i actually do that quite often too, pull parts of the matte with the differences between fore-and background brightnesses. I got the impression that you wanted to light the background brighter than anything in the foreground.

As a side note, i actually even wrote my own keyer for After Effects that has that kind of luma-matting as a feature, to help to extract i.e. shadows or lens flares from greenscreen. It's still a work in progress but if you (or someone else) wants to have a look, PM me and i'll send you a copy to play with. It's written with PixelBender, needs CS4 or newer.

Well ... I think you missed my point. The talent has colored their hair unbeknownst to you. "Talent" can sometimes be mildly insane from my perspective

Yep, i noticed, and re-wrote some of my previous message - there were other silly things there too. It's been a long day...

I've had that exactly that surprise happen. I was hired for a music video. We did our prep, and our pretty brunette singer agreed to everything. We get a green screen studio, arrive early, prep, stage and light. Then she shows up, right at her call time, with green hair.

What could I do? We were in a studio with walls painted green .... we had no other screen materials on set. At the very least, we would have had to acquire some bluescreen or other choma screen material. We might have had to do a company move. It could easily have cost the day.

So (and this is when I invented this idea) since I had the lighting power, I turned up my lighting 2 stops and pulled a luma key on set as a test. It worked splendidly.

Now its a part of my standard practice.

Rather cool - i guess i should do some tests of my own.

You mean how do I eliminate the shadows in the key?

No, i was just joking. Forgot the smiley there...

I don't. I try to pick ranges which key just the shadows, color correct them as a separate layer and put them back on the background. When that doesn't quite work (as happens most often) I can use it as a guide for generating shadows in 3D, then I add them to the shadow key, and add that mess back in to the plate.

Yep, i do similar stuff quite often. It's actually pretty rare to get a wide plate with a talent standing on the screen, and get an usable result with a single keyer. It's almost always a juggling excercise of one sort or another ;-)