Film-Tech Forum ARCHIVE: RGB vs YCM

This is topic RGB vs YCM in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Monte L Fullmer (Member # 2797) on 08-04-2010, 04:25 PM:

Here's an interesting question (or just thought) that I felt that belongs here in this "straight to video" forum, and kinda wondering about this and any comments are helpful.

We know of the two forms of colors - additive and subtractive.

Additve is the RGB and Subtractive is the YCM

Digital, analog three color analog monitors are the Additve.

Reflected visable items and film are the subtractive.

Now, we're going into the digital phase of projection which is using the RGB form of light, yet the movies shown from these units are based from YCM or subtractive sources.

Aren't we kinda defeating the purpose of using one to show the other?

thx-Monte

Posted by Bobby Henderson (Member # 840) on 08-04-2010, 04:56 PM:

Not all of it is subtractive.

Video cameras record in RGB, but ones used in "filmmaking" have their output modified in an attempt to look more like film and get rid of the 6 o'clock news/soap opera daytime TV show look associated with video cameras.

Most new movies shot on film have their negatives scanned, with the resulting data usually captured in RGB color space. The color in that data can be modified to go beyond the limited gamut range of CMY/CMYK color space.

Posted by Monte L Fullmer (Member # 2797) on 08-05-2010, 01:39 AM:

quote: Bobby Henderson
but ones used in "filmmaking" have their output modified

Be like when Lucas shot SW:EP-III : he shot that all in digital but prob had it modified to look like it was shot on film ...

Okey,that'll work then .... lots to learn .. thx-Monte

Posted by Anders Nordentoft-Madsen (Member # 3334) on 08-06-2010, 02:34 PM:

quote: Bobby Henderson
Video cameras record in RGB, but ones used in "filmmaking" have their output modified in an attempt to look more like film and get rid of the 6 o'clock news/soap opera daytime TV show look associated with video cameras.

Is this not more of a Progressive vs. Interlaced thing?

Posted by Mark Ogden (Member # 43) on 08-06-2010, 02:50 PM:

It's a few things. It's progressive scan and changing the frame rate, but a lot of it is changing the gamma curve characteristics to more closely emulate the look of film, and careful manipulation of detail levels. Bear in mind that this applies only to those "electronic cinematography" cameras that still output a fully gamma corrected, 4:2:2 HD-SDI signal. Many other cameras, like the RED One, the Alexa and the Genesis, output only off-sensor data, and nothing in the actual camera output is modified at all. The finished image is built from the ground up either on an on-set CMS look-up device, or in post production with a color corrector.

Posted by Bobby Henderson (Member # 840) on 08-06-2010, 02:53 PM:

Unaltered video still looks like video even if it is progressive scan. I can shoot something in 480i using my old MiniDV camcorder or record footage in 1080p/24 using my Canon EOS 5D Mark II. Footage from either source will still have that video look unless the color is altered. The 1080p/24 material would be easier to manipulate into looking like film since the stream is progressive and far higher in resolution.

BTW, even material from cameras like the Panavision Genesis has to be altered in post. Its native output still looks like video. The commentary track for The Lookout made note of this. The filmmakers were unsure about the Genesis based on raw tests because the stuff looked like video. Once the footage was gussied up in post they liked the end results. Regardless, a lot of Genesis-sourced movies are plagued with the video look. I think Get Smart is one of the bigger offenders in that regard; it's low light scenes are terrible.