Black background, can see foreground

[gorillaonabike]

I am doing a shoot in a small space where I need the background to be dark but the subject to be lit. Mostly, this needs to be close-ups of instruments in a way that we cannot see the background.

My kit is:

Four redcaps (800w each, dimmable)
Three LEDs, all dimmable but not directional because they are LEDs

Anyone have any ideas on how they have done this or how they would do this?

 

[WhiteOpus]

Keep the subject (the thing you want to be lit up) far from the background.

Put your lights as close to your subject as the framing will allow, as bright as possible so they're extremely bright in comparison to the background. I mean BRIGHT. You're going for contrast here, so even though your eyes have the "dynamic range" to "expose" for both the bright subject and the dim background simultaneously, the camera can be fooled into only displaying one or the other by having to compromise between exposing for either the bright areas or the darker areas.

Use barndoors or blackwrap to direct the light onto your subject and not onto your background.

And finally, the most important thing is to now expose for your bright subject, which should make the rest of the scene go dark.

I've had luck with this in the past, but I'm no lighting expert. Just what worked for me on a VERY low budget.

 

[WalterB]

Light from above with a black flag or 'skirt' to keep it away from the background could work, but your space might be too small for that...
Also make sure you don't bounce so much light to the background that it becomes visible.

Just remember the fall off of light: twice the distance = 1/4 of the light left.
So what White Opus says uses this charactaristic.

 

[gorillaonabike]

Thanks ITers, really appreciate it!

 

[sfoster]

I've done this.. I got a black tarp and I draped it in the background.
Covered all the windows so there was no other light and used snoot boxes to control my spill

 

[jax_rox]

I would suggest you may need some black fabric to really 'sell' the black background.

Cameras these days can be too sensitive for their (your) own good in situations like these. I shot something recently which needed a similar effect, and after we set the lights we realised we needed to put blacks up for the background, because even though the bg was quite underexposed, it was simply 'very dark' and not 'black'