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View Full Version : I'm shooting a car scene with keyed out windows



joshtownsend
08-20-2006, 05:55 PM
Any tips. Obviously I'm shooting Poor Mans Process (not moving the car). The wil be tight I know how to pull a key. WHat I am worried about it is being able to see the windshield glass even though I'm shooting greenscreen behind it.

Do I need to shoot a seperate element of glass? I can key the glass out completely, but then it looks funny.

Only idea I had, is to shoot the moving background plate (to be seen through the windows) through and actual window.

Any way to do it in the comp though.

Justin_Kirch
08-20-2006, 07:10 PM
so, are you saying you still want the windshield in the shot and having the background plate moving? you can still have the windshield in the shot while doing this, just light it well and watch for reflections...

if you are saying you want the car to look like it's moving and having a reflection off the windshield, shoot a separate element of the camera pointed up at the trees, put this element over the whole composition, then mask out the windshield and only have that part seem like it's reflecting the trees.

put the opacity down to 30% or so, so you can still see the talent inside the car.

joshtownsend
08-20-2006, 07:44 PM
Yeah well I think the windows have to be in the shot. The scene is to pages has the main character talking to himself. It's a Gollum/ Smeagle type seen. I want the background to change depending on which personality is talking that's why I'm doing the green screen.

We can light it so there no reflection in the glass when I shoot inside the car so I can get a greenscreen.

It's just when I did a test it didn't look right with out the glass being there.

I guess I can shoot the moving background plate through a window and it will give me the effect.

Is there I can shoot the glass again black or white and blend with opacity like your talking about except I want to see out of the car?

Anyone ever shot anything like this?

FilmMagic
08-20-2006, 07:57 PM
I'm not totally sure if this fits in with what you're doing. My thought would be to put the green screen in FRONT of the windshield. That allows you to key out without worrying about the windshield being seen. Then do as Justin was saying by shooting footage of the trees, masking out the windshield, and knocking the opacity down to about 30% or so.

Neil Rowe
08-20-2006, 09:31 PM
clean the glass to perfection, and then use a polarizer and you can dial out any glare off of the glass as long as you are careful with your lighting. with the polarizer and clean glass you shouldnt really be able to see the glass at all. however, alot of windsheilds in particular have striations running through them horizontally which show up through a polarizer at the same degree that normal glare is removed at. side wondows arent plagued by the same issue, so rethinking shooting angles may not be too bad of a thing to consider pending what importance the frontal shot plays.

Matt Grunau
08-20-2006, 10:35 PM
In addition to what has been said, most times, light values reflect more off glass, so you may want to think about using a lightening blending more instead of just turning the opacity down.

Usuall, it's only the light portions we see reflected. the dark parts have no opacity.

floatingtrem
08-21-2006, 10:48 AM
it looks like most people are misunderstanding what you asked. Shoot the moving footage through a window. That's really the only way to solve your problems. at least without it looking funky.

kai
08-21-2006, 01:04 PM
I'd do like neil mentioned and shoot with as little of the actual glass showing up on tape, then add it later in the compositing stage. Reflections, refractions, etc can all be added back.

joshtownsend
08-21-2006, 03:38 PM
it looks like most people are misunderstanding what you asked. Shoot the moving footage through a window. That's really the only way to solve your problems. at least without it looking funky.


Thanks for the help. I think your right. Shooting the moving footage through a window is the easiest way to go with adding a 3d glass effect or something.