lighting a bluescreen

m.avidov · Sep 13, 2004

can anyone give me pointers on how to light a bluescrren, so as to produce a sort of hay-low (mispelled, sorry) around the actors (so it can be cut later in after affects).
the screen might be on wheels, therefore i know that the lighting, has to move accordingly.
this is planned to be shot at night, outdoors.

any help, would be greatly appreciated.

thanks

DerekEastham · Sep 14, 2004

see the lighting about lighting for green screen post... that will all apply to blue screen as well, as they are both the same technical achievement with different chroma colors.

http://www.studentfilmmakersforums.com/bb/viewtopic.php?t=445

Kevin_Zanit · Sep 21, 2004

The last show I was on, ILM wanted the screens 1 stop over. I usually light them 1 stop under because I find it easier to deal with the spill. Either way, every company has their own preferences, so I just do what they ask.

Kevin Zanit

laurent.a · Sep 21, 2004

Interesting point, Kevin

Kevin_Zanit · Sep 30, 2004

It surprised me also Roy, but that’s what they asked for. I like the screens a stop under, because of the spill issues. To counter it, we just got further from the screen. I have sometimes used 1/4 minus green on a backlight to fight spill when I can’t get far enough away, but I try to avoid that if I can.

Kevin Zanit

laurent.a · Nov 13, 2004

Mr Wagner,

I've seen the Bogen system at the satis last week. It actually is a 3m scotchlite screen that is used. It looks very clever, I was amused to see 2 different other systems based on the same trick there but I forgot to ask a question : i'd like to know how you determine the background exposure in this case...

When I do transflex I spot measure in different areas of the projected image from a place as close as possible from the lens axis. It's not a problem, since you don't need the camera in place and can take the measure before it's put in place. Do you put the ring firrt, and meter from where the lens is going to be ? If you spot measure, what value do you give to the background ? KL ? (I mean, the reflectance of the blue screen is a point and the spectral sensitivity of the spotmeter another...)