XH-A1, Colorspace, Chromakeying and Apple's Color

[Terry VerHaar]

Hi Gang,

I have been a huge fan of Canon for a long time and have been pretty sure my next camera would be an XH-A1. However, Apple's new FCS6 and it's inlcusion of Color have gotten me to rethinking the issues of colorsapce in general and and more narrowly about chromakeying.

Supposedly color grading and chromakeying are much easier and produce better results in a 4:2:2 colorspace. While an HVX-200 and other "pro" format cameras (DVCpro, XDCAM, etc) produce the 4:2:2 space, the XH-A1 does not. My question to XH-A1 owners and others "in the know" is whether this is really a limitation in what you can accomplish in post? If I plan on shooting a fair amount of green screen and working in Color to grade my projects, will I be frustrated with the HDV signal from the XH-A1?

Thanks.

[Michael Richard]

seems most people are saying do all your editing in hdv then drop it in a Prores timeline for CC. ProRes is 4:2:2 10bit.

[David W. Jones]

I have done key work with footage from many different cameras, shot in many different formats, from 35mm to mini DV and everything in between, including footage from the XH-A1. And IMHO, the biggest issue I face for pulling a clean key is not the color space limitations of a particular format I may have to work with. But rather how the shot was lit during production.

[Mike Gorski]

Originally Posted by Michael Richard

seems most people are saying do all your editing in hdv then drop it in a Prores timeline for CC. ProRes is 4:2:2 10bit.

True, but if its already compressed then you can't regain the lossed information after it has been processed as an HDV signal. Terry, I 'm not sure how mobile you need but since your green screening look into the G1 if you really love Canon and the setup of the XH series. You will get the HD-SDI port which in turn you can gain that extra colorspace due to the uncompressed signal. Now the signal is super high as you may know but with the AJA IO-HD you can use Apples ProRes 422 codec and gain all the benefits. Its said you get uncompressed quality at manageable SD file sizes. So All you need is a Apple laptop or an apple computer for that matter with final cut and your set. Watch this short video by freshDV its pretty sweet. Explains more in detail from NAB 2007 on what I just mentioned.

http://www.freshdv.com/2007/04/nab-video-aja-io-hd.html

[Blake Calhoun]

You're really talking two different things here. Using Color in FCP would not be an issue at all shooting in HDV. You're simply color grading the footage. The thing would be when you render out your new graded files (you have to render them, it's not real time) you simply do this to a different codec like the new ProRes 422 or DVCProHD.

However pulling keys with HDV, it really depends on how high-end you're talking. I have pulled descent keys with standard-def DV footage for years when folks said not to. But this was for medium-budget range corporate work, so it was okay. If I'm doing higher-end commercial work or feature work you're probably better suited to use a different 4:2:2 format, or as mentioned bypass the MPEG 2 by using the HD-SDI output of the G1 or similar camera.

[Todd Smaretsky]

The xh a1 does shoot at a sampling rate of 4:2:2

[David W. Jones]

Originally Posted by Todd Smaretsky

The xh a1 does shoot at a sampling rate of 4:2:2

But gets recorded to tape at the HDV spec.