How do you alter the ratio of data during creation of an RGB image?

[Martin-Devon]

I'm trying to follow a Rob Gendler tutorial on Photoshop processing and key to this is the ability to vary the actual ratio's of the individual RGB data that goes into generating the composite RGB. I thought this would be simple, but I've messed around & cannot seem to get it to happen.

I've tried the basic steps of creating an RGB, opening first the Red data, converting from grayscale to RGB, opening up channels and then pasting in the Green & Blue - so I get the coloured RGB but cannot vary the ratio. I've tried alternatively to opening just the Red data, converting from grayscale to RGB and then layering in at 50% (or anything between 10-90%) opacity the Green & the Blue on top - but although I get an RGB composite it remain gray, so I'm obviously doing something wrong, but it does allow me to alter the ratio....

Any tips you can suggest would be appreciated - thanks

[steppenwolf]

If you want to reduce one of the colour channels from your RGB image, go to 'Channels', click the channel that you want, to make it active, then type Ctrl 'A' to select the contents followed by Ctrl 'C' to copy it to the clipboard. Select File - New and choose a white background followed by Ctrl 'V' to copy the original channel into this new file as a layer. Adjust the opacity of the top layer of the new image then flatten the image. Finally, Ctrl 'A', Ctrl 'C' then select the original image again and Ctrl 'V' to insert the reduced intensity image into the required channel.

[ollypenrice]

If you want to reduce one of the colour channels from your RGB image, go to 'Channels', click the channel that you want, to make it active, then type Ctrl 'A' to select the contents followed by Ctrl 'C' to copy it to the clipboard. Select File - New and choose a white background followed by Ctrl 'V' to copy the original channel into this new file as a layer. Adjust the opacity of the top layer of the new image then flatten the image. Finally, Ctrl 'A', Ctrl 'C' then select the original image again and Ctrl 'V' to insert the reduced intensity image into the required channel.

Well I never knew that! Good question, good answer.

Olly