chroma key with HDV or HD footage

[John Fishback]

Good advice using magenta and amber as minus green/minus blue. Not to harp on a number, the reason we go with lower light on the green/blue is to reduce spill.

John

MacPro 8-core 2.8GHz 8 GB RAM OS 10.5.4 QT7.5 Kona 3 Dual Cinema 23 ATI Radeon HD 3870
ATTO ExpressSAS R380 RAID Adapter, PDE Enclosure with 8-drive 6TB RAID
24″ TV-Logic Monitor
Final Cut Studio 2 (up to date)

Pro Tools HD w SYNC IO, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec Monitors, PrimaLT ISDN

[Chris Borjis]

[Bret Williams] “I would assume HDV is even worse at keying than regular DV since it’s 4x the resolution at the same bitrate 25mb/sec.

DV is pretty horrible for keying. Shoot the regular HD vs. HDV if you can.”

DV is much worse than HDV in my own experience.

And forget keying in final cut pro with these formats, you will never
get a really great key that way without compromise.

You need to key from a compositing app like, Shake, or After Effects.

the keylight keyer in After Effects is what I use and it looks fantastic.

[Andrew Kimery]

[Dave LaRonde] “Well, not quite.

HDV resolution is 1440×1080, and HD resolution is as high as 1920×1080.

HDV’s color resolution stinks on ice, and since the object is to chroma key the footage in question, it’s a bad choice.
HD’s color resolution is at least 4-2-2, and on the pricier cameras it’s 4-4-4, which is an absolute dream to key… that’s as long as do your due diligence to ensure a good key in the first place.”
Not to derail the thread but HDV, Blu-Ray, HDCAM SR, DVCPro HD, XDCAM EX, etc., are all HD just like VHS, DV, DVD, 3/4″, DigiBeta, etc., are all SD. HDCAM’s codec is 1440×1080 w/3:1:1 color sampling but I don’t think anyone is going to say HDCAM is not HD. 😉

-A

[Andrew Kimery]

[Dave LaRonde] “Technically, you’re probably right.

Now let me ask you this: in the standard-definition world, if you needed a good-quality image, would you prefer Digibeta or DV?

I maintain that in terms of picture quality, HDV would be the absolute LAST what you call the HD world, barely even worthy of being referred to as HD.”
In terms of image quality DV and HDV are towards the bottom of their respective barrels but saying DV isn’t an SD format or HDV isn’t an HD format is just plain inaccurate.

-A

[Geir Ove thorsveen]

With the EX1 and green screening, the route to paramount image quality would be to use the HD-SDI output on the camera. For this you would need a MacPro with some kind of HD-SDI capture card (Decklink, Kona), and raided hard drives.

This would allow you to get the uncompressed HD-SDI signal straight out of the camera block of the EX1. The quality of this image is surprisingly good, even compared to cameras like Pana 2100 or Sony PDW-700. With fast enough drives, you could capture this as uncompressed HD, or maybe ProRes or DVCPro HD.

Of course there is a practicality issue in this, having to haul a 30 lbs. editing system with monitors and everything around isn’t always an option. But if your green screen studio is just down the hall from the editing rooms, you wouldn’t have to move anything, just run a cable.

I just did a green screen test with the EX1 this way, and I very nearly peed my pants. If it is practically feasible, this is the way to go.

Geir Ove Thorsveen
Head of Technology
Lillehammer University College

[Elijah Lynn]

I have used Primatte Keyer Pro 4.0 and I must say that while it is pretty decent and could get better depending on my skills and equipment.

It is slow, just really slow and it does not use more than 1 core of your computer and it does not use GPU. It is pretty far behind. I would have chosen DV Matte Pro except I got a better key through the Primatte demo first.

Neither one of them have good support for their software from the companies, meaning that I couldn’t send a sample and having them help me with the settings.

I am still looking for a good and fast keyer. DV Matte Pro is very fast as it uses GPU and is realtime in the timeline.