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-   -   HDV and Green Screen (https://www.dvinfo.net/forum/general-hd-720-1080-acquisition/62949-hdv-green-screen.html)

Dean Steinmann March 15th, 2006 05:57 PM

HDV and Green Screen
 
I've read a few posts regarding the HDV format and its performance in the green screen arena. All were negative.

We have been doing green screen work for a few years using DV Cam equipment. I always read that DV was not suitable for green screen work and indeed it was a tad sketchy. But with the purchase of a plugin for FCP from DV Garage, and the honing of our skills through the school of hard knocks, things improved greatly.

Is the HDV format any better or worse than DV Cam for keying? Does anyone know of any plugins (I see there is a plugin at dvgarage.com for Motion) available to improve the outcome?

Is anyone keying now with HDV as source footage?

Keep in mind that we are producing for the internet where our subjects are only about 400 pixels tall, like this example we produced here:
www.cashadvance.com

My hope is that with the higher res offered by HDV, we can increase (perhaps double) the size of our subjects with good results.

Regards,
Dean

Chris Barcellos March 15th, 2006 06:29 PM

I haven't tried a green key, but in PPro 2, I,ve keyed with blue screen in both DV and HDV. After rendering to 30P format, had a very nice key affect. I'm not heavy into keying though, so your standards may be much different.

Dean Steinmann March 15th, 2006 07:17 PM

Thanks Chris,

The plugin that we work with, DV Matte Pro, works best with green. Much better than what comes standard with FCP. We have worked with blue as well, when the subject needs to wear green for some reason.

Dean

Douglas Spotted Eagle March 15th, 2006 08:19 PM

We key at least once a week using greenscreen or diff masks, and HDV performs wonderfully.
I'd wager 95% of the posts from folks that say it won't key are folks thinking 4:2:0 PAL DV is the same as 4:2:0 HDV/MPEG, and they're not at all the same. Just more folks that read math and never actually do this stuff.
In fact, in a recent shootout between formats, the Canon, JVC, Sony, and even the little Sony Z1U beat hell out of the "other" low cost HD cam out there, and beat hell on a couple of other lower compression SD formats as well.
No worries. Whether working in Ultra2, Ultimatte, or Sony Vegas, it's EASY to pull a good key from HDV, both with m2t or CineForm avi.
For virtually any 1/3 digital format, green is best due to the luma value of green. To better understand why, put a set of SMPTE colorbars to your monitor, then apply black/white filter, removing all color. Notice what colors are brightest? (other than white, of course)

Steven White March 16th, 2006 09:57 AM

I had no problems shooting some tests on my FX1. Best results were acheived with (of course) 0 dB gain and a green screen. Everything else depended on content.

CF30 modes were easier on the compressor and produced slightly less compressed results, and macroblocking was visible in heavily motion blurred areas of the key - however, played back in real time they really aren't noticable.

-Steve

Dean Steinmann March 16th, 2006 12:25 PM

Thanks for the input!

Dean

John Hewat March 18th, 2006 05:11 AM

Hi guys,

I've just started a thread about green screens here asking for recommendations. If you've had successful results I'd love to know what you were using.

Thanks,
-- John.

Douglas Spotted Eagle March 18th, 2006 10:44 AM

There is a fabric, I've forgotten its name. Anyway, you can find it at most theatrical stores or on Ebay. It is foam-backed, and has small loops in the fabric that helps prevent light from reflecting from it. We found a guy on Ebay that sewed us a 24' x 18' piece with grommets and stress points for only 170.00. The fabric has been great, no challenges at all. (except for where someone accidentally sprayed beer on the screen)
Easy to work with even when lights aren't perfect.

Gary Gowman March 19th, 2006 06:44 PM

Also check out Serious Magic Ultra 2. I have been using it now for the last week and find it to be very fast, easy and good. I have tried them all, Ultimatte, Primatte, Combustion, etc and this program is cool. Take the time to try it "all' out. It keys fast and is tweakable. It keys easily with wrinkles and different shades. It uses vector keying. They are showing a small portable green/blue screen called Instant Backdrop. One side is blue and the other is green. It folds up like a light reflector. It is at the bottom of the webpage.

http://store.seriousmagic.com/seriou.../upgrades.aspx

http://www.seriousmagic.com/media/Fo...20Backdrop.wmv

and the app

http://www.seriousmagic.com/products/ultra/index.cfm

Best regards,
Gary


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