what is color phase exactly?
 

hi guys, wondering if someone could tell me exactly what the color phase setting does. I can't seem to find much info on it....

I don't have an A1 (yet, but soon) but everywhere else in the video world you can call it "tint" - try adjusting the "tint" control on your television to see what it does - then aim your cam at someone's face (with good light) and see if adjusting the phase control does the same thing... Steve

Have you checked page 65-67 of your manual?

yeah, the manual doesn't give much information at all about the cph setting. But it being a "tint" function makes sense.

Phase is the strictly correct term for what is often termed "tint" or "hue" on consumer equipment.

It is really on of significance for NTSC video. It refers to a phase difference added to a colour reference signal used to decode the colour information. (PAL video removes the need for a colour reference signal using a technique that inverts the phase every video line - hence the term "Phase Alternating Line").

See http://en.wikipedia.org/wiki/NTSC#Color_encoding for description of how the colour information is encoded for NTSC.

if you can envision the colors on a rainbow, the analogy is to a wheel of color, where primary and complimentary colors are juxtaposed on a continuous circle or wheel. Thus any primary color, when combined with its opposite on the wheel, yields a neutral gray, luminance with no chroma. Now, if you can wrap that around your brain, think if phase difference as a rotation of the wheel. So that a phase difference of 180 degrees is the complimentary color, a phase difference of 360 degrees returns to the original color, and so on.

wow! thanks john, thanks bill! Thats exactly what I was looking for, i can't imagine a more straightforward response explaining color phase technically and conceptually. These boards a great! A big thanks to everyone who answer all my silly questions!

This is what the vectorscope is for. It displays color phase information to you as well as saturation. As was stated, a given color in the NTSC system has a phase relationship to the reference signal (chroma burst). The AMPLITUDE of the chroma burst signal determines color saturation. So, when you look at the vectorscope, the display will show a given color as a position on the circle and the saturation will determine how far away from center the display is.

-gb-