Does Amber+Magenta=Red

[neumanns]

Everything is based on RGB except the WB on the XTI wich is based on four colors...Blue, Green , Amber, and Magenta.

Now my assumption would be to color correct blue or green to the positive you add shift in this direction.

But how about to correct in the positive of red...is it equal parts amber and magenta?

Now to further complicate things...How do you correct in the negative for Blue and green?

Is negative Blue=amber or is it some combination of amber and green or magenta?

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I am not sure if I just have a brain fart on this or if it is basic primary color stuff! But for some reason making three colors with four and vice versa is making my pea sized brain hurt....Make it stop hurting!

[DAMphyne]

I'm not sure either where the amber comes into play. Color balance in PS shows
Red----Cyan
Green----Magenta
Blue-----Yellow
Add Red to reduce Cyan and vice-versa. Add Green/reduce magenta, Add Blue/reduce Yellow
Yellow is amber, but I've never seen it described that way in any photography, except maybe filters.
Amber filters in printing negative based prints deepen blues.
Sorry I'm not more help, this is new stuff to me I guess.
Hope you can get an answer.

[neumanns]

Just a project in my "self study" to become more proficient with my toy...how to better understand it and in turn improve my ability.

Thanks for your reply!

I assume the use of four colors are some attempt at using subtractive coloring or whatever they call it YMC vs RGB...I am just having trouble getting my head around the two once combined!

That is "if" my assumption is correct that it is a combination of the two color systems, perhaps this is where my error is and why I am having trouble with it.

Maybe amber is red...but then why throw magenta in the mix?

[gjl711]

Hmm… From my old are class days, Amber is a shade of orange. Its compliment is blue.

[neumanns]

Ahhh...perhaps,

If Magenta is to green, what amber is to blue!

But where is the Red?

Isn't the sensor and the color space etc all based on RGB

Or is red equal parts amber and magenta?

[neumanns]

Ok...Red and cyan are missing!

The answer to my question is no!

I can only adjust blue to the positive or negative (amber or Yellow)
green to the positive or negative (magenta)

There is no adjusting the red...only adjusting the other two colors to affect how it appears but no adjusting it!

Perhaps a better question is why amber...shouldn't it be yellow?

Perhaps another day!!!

[PacAce]

Everything is based on RGB except the WB on the XTI wich is based on four colors...Blue, Green , Amber, and Magenta.

Now my assumption would be to color correct blue or green to the positive you add shift in this direction.

But how about to correct in the positive of red...is it equal parts amber and magenta?

Now to further complicate things...How do you correct in the negative for Blue and green?

Is negative Blue=amber or is it some combination of amber and green or magenta?

.
.
.
I am not sure if I just have a brain fart on this or if it is basic primary color stuff! But for some reason making three colors with four and vice versa is making my pea sized brain hurt....Make it stop hurting!
There are three colors that, when mixed in the equal proportions, make white. They are Red, Blue and Green. When there is a color cast, so that white does not appear as white, then there is an unequal proportion of one or two of those three colors. So, to correct the color cast, only one or two of those colors need to be adjusted, not all three. And hence, the reason why the WB correction only have adjustments for Blue and Green. Amber and Magenta are just absence of Blue and Green. All that needs to be done to correct WB is to change the proportion of Blue and/or Green relative to Red. If Canon had wanted to, they could have used Blue and Red adjustments relative to Green, or Green and Red relative to Blue.

If, for example, a picture has has a bluish tint, you can compensate for that by moving the Blue/Amber slider towards the Amber side. If, on the other hand, you have an amber color cast (too much Red and Green), then you would correct for that by moving the same slider towards the Blue side.

Hope that helps. :)

[coreypolis]

http://img.photobucket.com/albums/v721/viperx27/ColorChart1.jpg

the additive and subtractive properties of the color wheel

the old adage is:
Really (Red)
Young (Yellow)
Girls (Green)
Can (Cyan)
Become (Blue)
Mothers (Magenta

and is drawn in a circle


http://img.photobucket.com/albums/v721/viperx27/color.jpg


so yellow and blue go together, magenta and green, red and cyan

[DAMphyne]

Man, How do you guys remember all this good stuff.
Is it true that memory goes second?
So the pixels on my sensor are just Red & Green?

[gjl711]

Man, How do you guys remember all this good stuff.
Is it true that memory goes second? I don't know, I cant remember. :)
So the pixels on my sensor are just Red & Green? 1 red, 1 blue, and 2 greens. Check out this link. It tells all. "click me (http://en.wikipedia.org/wiki/Bayer_filter)"

[coreypolis]

Man, How do you guys remember all this good stuff.
Is it true that memory goes second?
So the pixels on my sensor are just Red & Green?
in the film days you had to know, theres no white balance, just outdoors or tungsten film, and you had to use CC filters to acheive proper WB. you'd have to be spot on too, and know x light requires 5 points magenta etc

[DAMphyne]

gil711, Thanks for the link, I find this stuff very interesting but most of it flys over my head. Maybe through the empty lot between my ears.
coreypolis,
In 1974 I worked for a Pro Product Photographer, he could walk into a room and know what filters he would need to get the shots right. I chased after the filters, mixed chemicals and swept the floor.
What I wouldn't give to know that I should have paid attention.
Thanks for the memory nudge.

[gjl711]

..In 1974 I worked for a Pro Product Photographer, he could walk into a room and know what filters he would need to get the shots right. I chased after the filters, mixed chemicals and swept the floor.
What I wouldn't give to know that I should have paid attention.
Thanks for the memory nudge.
His name wasn't Fritz, was it? I got my start in a very similar way a few years later apprenticing for Fritz. Had to set up light, set filters, adjust backdrop, all the fun stuff. Then he would come in and in a heavy German accent tell me everything was fu**ed up, take the picture and on his way our croak next time, do this, do that, and leave. He really knew his stuff though and I learned a tremendous amount from him most now forgotten.

[DAMphyne]

:) No his name wasn't Fritz, it was Patrick. Sounds like they came from the same school though.
"If you can't do it right, what are you hanging around for?"
Wish I could remember half of what he tried to teach me.