Color Channels: What makes them so extra special?

[Andymania]

Hey guys,

Again, re-reading Dan Margulis' material and how he uses channels for the apply image command to create better detail and how certain channels have better detail info than others. Now in regards to channel blending, what exactly does that do? He mentioned that he would blend the red into the green, etc. After expirimenting with that, I did learn that blending channels via apply image really creates wacky colors. But I am still a little uncertain as to how channel blending works and what it does. If anyone can give me a nice explanation, that would be great.

-Andy

[mshi]

You may want to read this book too:

http://www.amazon.com/Photoshop-Chan.../dp/1562057235

[ShadowLight]

I don't know what that author has written about,
but to blend channels probably you should go with Channel Mixer.

for example...
Output Channel: Red
source channels: red +80, green +20

this will get some of the green signal towards red and lower the red's intensity
(it's suggested that you keep all values added to 100)

[mshi]

I thought Calculations command has been around since the first version of Ps. No?

[RobertAsh]

Hi Andy,

Channel blending is used sometimes to get better black and white images. It allows you to make reds/greens/blues/etc. lighter/darker, which alters the way your shades of gray come out in black and white images.

Beyond that, I don't know, haven't used it and I don't think I'm that far into Margulis' book (I worked all the way through about half of it awhile back, then got busy working and haven't finished it yet).

[czd]

Andy,
Try experimenting this on a duplicate -merged- layer, in luminosity mode.
Regards.

[MacBurg]

I use channels a lot for various things -

To make a colour specific selection by duplicating the channel, applying levels to increase blacks and whites then painting with the brush.

To shapren in different ways, when you have a lot of blue in the image you will have a very contrasty red channel, sharpening this will always be a good way to go, vice versa sharpening the blue channel can be a good way to create a hyper sharpened portrait for a male model.

Adding a darkened mood to an image is easy by copying the information in a channel, pasting it into a new layer and setting this to Multiply blend mode.

Using a specific channels information to create a glow or colour cast.

The list goes on really and this isn't even using Apply Image or Calculations...

[redcrown]

Those doing channel operations might find this interesting....

http://www.youtube.com/watch?v=7HX9UJA3rEQ

[Andymania]

Cool guys thanks.