Tricky compositing infrared shots

[Darby Edelen]

[Dave LaRonde] “I guess it would all depend on the warmth of the body as to whether or not you could pull a good key.”

Here’s the other problem. I’m pretty sure he’s talking about the default night setting that a lot of consumer level mini-DV camcorders come with in which the camera isn’t sensitive to something as subtle as body heat.

These cameras work by using a light that illuminates the scene with infrared light. We can’t see the infrared light, but the camera does. This is the shooting mode made famous (infamous?) by the Paris Hilton tapes in which the subject appears bathed in an unnatural green light. And frankly I don’t think keying of any sort will work with it, especially seeing as you’re already talking about shooting in mini DV which has terrible chroma compression.

If you’re talking about using a built-in infrared light/night shooting mode on a mini DV camera then I think this is pretty much all around a bad idea. In addition to the other problems I’ve brought up, the infrared light only has an effective range of a few yards.

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA

[Steve Roberts]

Regarding the infrared, I think the best thing would be to shoot normally then fake the IR in post. It won’t be perfect, but you should get something useful. There must be a tutorial somewhere … at least Tinderbox has a nighvision preset, I hear … ($)

[Jonathon Sendall]

Thanks for info, to explain a little better. The body is suspended in water and approaches camera until illuminated by infrared light. This is then comped into a night shot of looking up into the night sky in a wood so it will look like a body descending from the inky black night towards the person holding a mini-dv camera with his infrared turned on. The suspension in water is only to give the effect of the body floating in mid-air not water since we don’t see water, right?

I could shoot this on HDV to make things easier in post but getting the infrared effect is pretty important and I would like to try and not fake it if I can. There are certain things that happen with infrared that don’t happen just by applying filters. So again there will be deep black behind the floating body and deep black in the shot looking up to the trees above. The fact that infrared will only light things in the 10 foot range from camera is a benefit, not a hindrance. It adds to the effect.

Story, not pixels.

Jonathon Sendall

[Darby Edelen]

[jpsendall] “The fact that infrared will only light things in the 10 foot range from camera is a benefit, not a hindrance. It adds to the effect.”

It sounds like you know what you’re looking for. If the area the body is going to be floating in is going to be pure black you could use a plug-in like unmult to remove the black from the floating body. This technique would cause problems if the body floats in front of any non-black elements though.

I’m still concerned about the dual technical limitations of mini DV and night shot though =)

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA