Green screen for car scene.

[Marquette Trishaun]

Hey there,

 

Could someone please explain how to position the green screen to windows in an automobile if you are trying to fake car motion.

 

For example, do you tape the cloth to the windows and back light it, or stand it vertical with about six feet of seperation from the car window of interest. Should the window be down or up.

 

For the effect of street lights as the car rolls down the street, do you just have someone pan a small light from left to right occasionally, switch a red or green gel in and out etc.

 

Obviously I can not afford to shoot with the car in real motion, and I really need this to cut right.

 

thanks in advance,

Marquette

[David Mullen ASC]

I'm not sure doing this in post realistically is necessary easier than doing it for real...

 

The greenscreen should be on a frame far away from the window; the larger and farther away, the less the green spill problems. Any shiny edges to the car should be dull-sprayed and perhaps softly backlit, if necessary, to eliminate green reflections.

 

You can leave the window up if you want, as long as what's reflected is the interior of the car, but you may need a better chroma key system to matte around something transparent like a ghost reflection on glass over green. So it may be simpler to have the window down.

 

A moving light design should be employed to realistically simulate passing overhead streetlamps, etc. I usually put someone on a ladder and have them wave a light handheld over the window shining down into the car. They move the light over the car, front to back, than then point it away while they reposition the light back to the head of the car. I have a lot of other lights moving, fading up & down, etc. It should match what is happening in the background. The background plates should be shot at the same focal-length as being used for the shot in front of the greenscreen and the focus should be on the to-be-added-in-post foreground subject.

[Mark Allen]

David hits the major points.... and yes - cahnging light on the faces is hugely helpful - however, don't OVER do the light changes - don't make it like a train is passing (common mistake).

 

Also - for windows, personally I like them if they are reflecting enough to get the actors on the inside of the car. That adds a great reality to the shot. I also like it if they are catching some of the light.

 

Almost always when doing a real key, you do a garbage but form fitting roto on anything that isn't moving in the frame and keep the rest of the key light enough so that refelections and detail remain - and soft parts of the hair. My favorite keying software is keylight by the way. If you're doing this in DV... DV is hard to key because the compression is square blocks which makes edges aliased. But... people do it.

[Marquette Trishaun]

Thanks a million for all the advice.

 

-Marquette

[Guest brooke928]

For this scenario with the car how should the interiors be lit? Obviously at night in real life not much light would be in the car, but there needs to be enough light for exposure. how to light this without it looking very flight and like there is obviously lights in the car?

[dremz]

dear member i can suggest u one film ....THE FAST AND TEH FURIOUS.....(vindisel)

 

in this DVD the making of the film is given very clearly with practical experienceing images (story board) u can go through there , i have seen a bit where the car driving by vindisel is shot beside green screen... it was amazing ,.. hava look..! guess u knw either ... :D