For folks who care about pixels :)
Reuben Finkelstein forwarded a great post from Creative Cow that's well worth reading, demystifying some of the talk about 2K, 4K, interpolation and more... :
The Truth About 2K, 4K and The Future of Pixels
by John GaltArticle Focus: John Galt, Panavision Senior Vice President of Advanced Digital Imaging, led the team that created the Genesis camera, was responsible for the F900 "Star Wars" camera, and continues to play a leading role in guiding future digital cinema technologies. In this Creative Cow Magazine Extra, join us for a wide-ranging conversation, as John cuts through what he calls the intentional obfuscation of marketing pixels, and considers the range of options that are becoming available to digital filmmakers.
John Galt: "Pixel" is an unfortunate term, because it has been hijacked.
Historically, 2K and 4K referred to the output of a line array scanner scanning film, so that for each frame scanned at 4K, you wind up with four thousand red pixels, four thousand green and four thousand blue.
For motion picture camera sensors, the word "pixel" is kind of complicated. In the old days, there was a one-to-one relationship between photosites and pixels. Any of the high-end high definition video cameras, they had 3 sensors: one 1 red, a green and a blue photosite to create 1 RGB pixel.
But what we have seen particularly with these Bayer pattern cameras is that they are basically sub-sampled chroma cameras. In other words they have half the number of color pixels as they do luminance And the luminance is what they call green typically. So what happens is you have two green photo sites for every red and blue.
So how do get RGB out of that? What do you have to do is, you have to interpolate the red and the blues to match the greens. So you are basically creating, interpolating, what wasn't there, you're imagining what it is, what its going to be. That's essentially what it is. You can do this extremely well, particularly if the green response is very broad.
Well 4K in the world of the professionals who do this, and you say "4K," it means you have 4096 red, 4096 green and 4096 blue photo sites. In other words...
Creative Cow: 4000 of each. 4K.
[Laughter]
John Galt: Right.
But if you use the arithmetic that people are using when they are taking all of the photosites on a row and saying they're 4K, they are adding the green and the blue together and saying, "Oh, there are 4K of those, so it's 4K sensor." Now actually, in order to get RGB out of a Bayer pattern you need two lines. Because you only have green plus one color (red) on one line, and green plus the other color (blue) on the other line. You then have to interpolate the colors that are missing from surrounding pixels...
By the way, great AniMotion NM event last night with Alex Lindsay on real world green screen production. I believe his talk will be online shortly.
--
NM Tech Council Event in Santa Fe:
Intel's Tom Greenbaum on Data Center Lessons Learned, Friday, March 13th @ the Santa Fe Complex
More info at NMTC: http://www.nmtechcouncil.org
Eric Renz-Whitmore, Program Coordinator
ARTS Lab
office: 505-277-2253
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http://artslab.unm.edu
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