Tips on Keying HDV footage.

[Brendan Coots]

Here’s a tip for keying HDV – Don’t.

Seriously, it’s the same bitrate as MiniDV, and not well suited for keying. If you want to get better results, try doing some searches here for keying DV, the same techniques apply.

[Aaron Zander]

as much as I would like to agree…

It’s fine, you cna key it very well ASSUMING it was lit well. You can key any footage on almost any format, as long is it’s shot/lit well.

I’ve keyed a good 100 hours of it…it’s fine

[James Purdie]

Hey..thanks for the support. I’ll try to get a better greenscreen when i get back to Canada and light it up well. Should be a lot easier than what I’ve been doing. Here in Korea space is so limited.

[Ron Lindeboom]

The best keyer that I have seen that works with HDV footage is the Boris FX keyer plug-in. Whenever I have to deal with this kind of footage, I go for Boris.

But as Aaron Zander points out, it only works with well lit green screen shots.

Lastly, don’t kid yourself that you are going to use this kind of key for a movie blown up on a big screen (or for other mission-critical work), it won’t work. But for many other uses it will be acceptable to a large part of the audience — even if it does have telltale artifacts that scream out to the eye of a discerning pro. (Which is what Brendan is alluding to.)

So, I think that both Brendan and Aaron are right. ;o)

Best regards,

Ron Lindeboom
https://www.linkedin.com/in/ronlindeboom
Publisher, Creative COW Magazine
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[Jason David]

How does dvMatte Pro hold up against Boris FX.

How should I light the green screen and subject, which should be brighter?

Thanks

[Brendan Coots]

The best (or perhaps ONLY) way to minimize keying flaws is to employ excellent lighting, like Ron said. This is true whether you are using a webcam or 70mm film, but with the prosumer formats like DV and HDV it can (and will) completely make or break your ability to key. This will probably involve using a lot more lights (and higher wattages) than some people are used to. Many people who work with DV are under the false-impression that DV allows you to work with little to no lights, or that cheap lighting instruments are okay. Not true. If you expect professional results, and especially while using an inferior format like HDV, be prepared to buy or rent a full set of professional lights. Anyone doing green screen or other pro-level videography should have:

– 2 or more 250w fresnel lights
– 2 or more 500w fresnel lights
– 1 or more 1k fresnel lights
– 1 or more four-bank kino-flo flourescent lights (or 1k soft-box fresnel equivalents).
– barn doors for ALL lights
– 2+ white cards for bouncing light
– Assorted flags, dots etc. for “sculpting” the light

As a general starting point for lighting greenscreens, I usually use two 4-bank kino-flos (or equiv.) on the greenscreen itself, one covering the left side of the screen and the other covering the right. Then I might bounce a 1k arriflex off of a white card to fill the middle of the screen. Having even illumination is very important, so it’s worth the time to really tweak your setup until the backdrop is as smoothly lit as possible.

It’s also very important not to over or under expose your backdrop. Overexposure will cause the greenscreen to lose saturation and shift toward the yellow, while underexposure will cause the screen to get grainy and shift toward the blue. Since the keyer will be comparing color values, it is crucial that the screen be as close to pure green as possible. One trick I have used in the past is to buy a pure green photographic filter. Hold a white sheet of paper up next to the greenscreen and put the green filter to your eye. A perfectly lit greenscreen will look similar to the white paper through the lens.