How would you go about lighting and shooting two actors attempting to touch but separated by a (hopefully invisible) sheet of perspex? Shoot it practically? Get them to fake it? Lighting issues?
Many thanks for any suggestions..
If you try to do it practically, bring a boatload of black duvytine or the equivalent.
The only way to make transparent sheet goods look actually clear - is to use unbroken negative fill to knock out anything that the angle of incidence/reflection shows - including the camera, lighting and crew.
Bill's got a very good point. He's also assuming the sheet o glass isn't as wide as the room, which would be expensive.
So, unless your actors are not gifted mirror mimes like Harpo Marx... whaddayado?
I have one idea; ultra-thin black vertical thread, under tension. Just one, where the hands must almost- meet. Use a wire removal rig like mocha or just paint it out in AfterEffects afterwards. But the thread gives the actors a practical target for placement of the hands, and limits their movement. Practical shoot with both actors maximizes the benefits of their timing and acting chemistry. Shoot with soft light and no shadows.
I have a second idea: shoot them one at a time, against a hard green cyc. They can beat on the virtual glass/force field all they want. Composite the two sides. Harder to edit because the actors can't directly react to each other - the editor will have to help with their timing. Suggest they use a practice session's audio as their guide, and loop the actual dialog/foley later.