Mac Keyboard Question

[Ken Lee]

The tutorial at http://www.retouchpro.com/tutorials/lum-mask-sepia.html
shows a great method to make warm-toned images. It uses a little-documented feature of Photoshop called the "Luminosity Mask". From what I can tell, it will do a better job than the Photoshop "Quadtones" method that I have been using, because it is inherently non-destructive, and can be used in 16-bit mode.

Following the instructions, we read "Open a single-layer RGB image such as a color portrait. Press ctrl-alt-~ (Windows) or opt-cmd-~ (Mac)."

I am unable to perform this on the Mac. It works as described on Windows.

It seems to me that the Mac analog of ctrl-alt is command-alt.

Furthermore, the ~ character is obtained by using the shift key.

So, what the heck is the correct sequence ?

One thousand thanks !

[Ken Lee]

Sorry to trouble you. I Googled the subject, and found that Photoshop has changed since the publication of that article.

Here is the method for CS3:

1) Open the Channels palette
2) CMD-Click on the RGB channel icon.

[Gordon Moat]

Hello Ken,

Works on my G4 PowerBook. If you did command 1, then that should show you the Red channel on an RGB image. Command 2 is Green, and Command 3 is Blue Channel. Then if you hit command ~ it should reload the composite RGB image.

Command option ~ is a very old feature. If you look at a LaB version of your image, then the L Channel should look similar. The selection is mostly based upon whiter and lighter areas.

Ciao!

Gordon Moat
A G Studio

[Ken Lee]

Thanks Gordon.

It's just as you say: the Lab channel holds the tone, and the Lightness channel holds the luminosity. Sharpening only the Lightness channel is another technique I have just learned.

It's time to crack open the books again.