What do channels do?

wrote:

I have been looking at an image that is mostly red. You can see it here if you are helps but it probably does not matter:

http://picasaweb.google.com/ronviers/Texture/photo#499746863 8958321682
When I go to the channels palette and look at the red channel it is almost all white. I thought the red channel was a distribution of neutral values used to represent the red hues, values and saturation of the image. This obviously is not correct so what is being represented by the individual channels?

Thanks,
Ron

I forgot to mention that I am working in RGB

Hi Ron!

What you see in channels is perfectly correct, as you are working in RGB space. RGB colors are rays of colors, and they are of additive nature, i.e. the deeper is the color the whiter is its representation in channels’ palette. While in CMYK colors are printed inks (subtractive nature) the deeper is the color the darker is its representation in the channels’ palette. So the value (255,0,0)-RGB will be represented as completely white in Red channel and completely black in the Green and Blue channels, as this indicates a BLACKOUT or there is NO RAY emitting from the green and blue channels, and that all the ray is coming from the Red channel.

Mohamed Al-Dabbagh
Senior Graphic Designer

wrote:

I have been looking at an image that is mostly red. You can see it here if you are helps but it probably does not matter:

http://picasaweb.google.com/ronviers/Texture/photo#499746863 8958321682
When I go to the channels palette and look at the red channel it is almost all white. I thought the red channel was a distribution of neutral values used to represent the red hues, values and saturation of the image. This obviously is not correct so what is being represented by the individual channels?

Thanks,
Ron

Mohamed Al-Dabbagh wrote:

Hi Ron!

What you see in channels is perfectly correct, as you are working in RGB space. RGB colors are rays of colors, and they are of additive nature, i.e. the deeper is the color the whiter is its representation in channels’ palette. While in CMYK colors are printed inks (subtractive nature) the deeper is the color the darker is its representation in the channels’ palette. So the value (255,0,0)-RGB will be represented as completely white in Red channel and completely black in the Green and Blue channels, as this indicates a BLACKOUT or there is NO RAY emitting from the green and blue channels, and that all the ray is coming from the Red channel.

Mohamed Al-Dabbagh
Senior Graphic Designer

Hi Mohamed,

That explains everything. CMYK works exactly the way I thought RGB was working. I guess I just noticed it because this was the first monochrome document I have worked with. Thanks for taking the time to clear that up for me.

Best regards,
Ron

"Mohamed Al-Dabbagh" wrote in message

Hi Ron!

What you see in channels is perfectly correct, as you are working in RGB space. RGB colors are rays of colors, and they are of additive nature, i.e. the deeper is the color the whiter is its representation in channels’ palette. While in CMYK colors are printed inks (subtractive nature) the deeper is the color the darker is its representation in the channels’ palette. So the value (255,0,0)-RGB will be represented as completely white in Red channel and completely black in the Green and Blue channels, as this indicates a BLACKOUT or there is NO RAY emitting from the green and blue channels, and that all the ray is coming from the Red channel.

Mohamed Al-Dabbagh
Senior Graphic Designer

what a smarty!!
good answer

wrote:

I have been looking at an image that is mostly red. You can see it here if you are helps but it probably does not matter:

http://picasaweb.google.com/ronviers/Texture/photo#499746863 8958321682
When I go to the channels palette and look at the red channel it is almost all white. I thought the red channel was a distribution of neutral values used to represent the red hues, values and saturation of the image. This obviously is not correct so what is being represented by the individual channels?

Thanks,
Ron

That is the best and most concise explanation of this confusing topic I have ever seen. Well done!