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View Full Version : Introduction to Mattes and Sky Replacent


Isaac
12-03-2005, 09:11 AM
Hello forum members! I'm a post guy who's just started an independent film blog called Outisde Hollywood (http://www.outside-hollywood.com/), and this week I've been trying to cover matte paintings (http://www.outside-hollywood.com/2005/12/matte-paintings/) and sky replacement (http://www.outside-hollywood.com/2005/12/color-correction-and-sky-replacement/). On the site is the first real matte painting I've ever done, and I'd love to get some feedback from everyone here on how it turned out, I'd also love to find out if there's anything that I left out of my article, or didn't explain well, or should change or expand.

homer
12-05-2005, 09:34 AM
that's a clean web site...
It might be good idea to talk a bit about the legend's work such as these as well...
http://www.mattepainting.org/index.php? ... ctionid=16 (http://www.mattepainting.org/index.php?categoryid=12&p17_sectionid=16)


Fusion and 10 bit log format
"10 bit" color space

You should be fine working in fusion with cineon files. All of the above information is valid, however, I will clarify a few things for you...

1) Fusion will automatically convert a cineon file to lin space on loading. It will maintain all the information in float color space, so details in the brights and darks are still there.

2) Be sure not to merge this footage over an 8bit or 16bit background, as this will clip all the extra data you are trying to keep.

3) Check your display for the "normalize color ranges" and use it often to make sure you are working in the brights and darks as well. (lights, flames etc, can all have detail there even though your display only shows white. )

4) When doing color correction, use the cineon tool, and convert to log space, and then use a color corrector to adjust just the brightness, then another cineon tool to convert back to lin space. typically a value of .0125 of brightnes = 1 stop

5) Be carefull when merging layers, as the default method for merge is to add alpha channels. This can result in an alpha greater than 1, and later merges creating dark areas in the image. (due to the math involved in a merge, where a background is multiplied by the inverse of the alpha.)