Blue skys every day

[bstreeck]

This is is the text for the following workshop:
http://www.trekearth.com/workshops/577923/photo89647.htm

I wrote this for a friend who wondered how on some pictures I got the blue sky so blue, after the original never had such a sky... just thought I'd share. (These directions are written for PSP X, but with PS it is the same, the commands are just called a little different sometimes. Anyone wanna translate to PS?)

- Create three new layers containing one color channel of the original per layer (one red, one green, one blue). (Whether you take a copy of the picture and create RGB separations and copy each channel into a layer or whether you duplicate your main layer three times and adjust the color channels to contain only one channel in monochrome output, doesn't matter.)

- Move the layers into groups as such:
> Sky Enhancer (Group)
+ Green
+ Blue
+ Red
+ Picture

- Turn the green and blue channels into masks. (Possibly you need to create a mask for the Red channel, move the whole blue layer into the mask layer and move just the mask layer back to where the blue layer was. repeat for the green channel. This is your result:
> Sky Enhancer (Group)
+ Green-Mask
+ Blue-Mask
+ Red
+ Picture

- Change the blend mode of the Sky Enhancer Group to Luminance.

- Basically you are done. Since this does not enhance the sky 100% selectively, you can add another mask as such.
> Sky Enhancer (Group) [Luminance Blending]
+ Limiter-Mask
+ Green-Mask
+ Blue-Mask
+ Red
+ Picture

- Select the Picture Layer and use the Magic Wand tool to select the sky. Brightness matching and a tolerance of 15 or so and a couple of clicks work great. Use this (inverted) selection to block out everything but the sky in the Limiter-Mask.

As mentioned, this does not actually enhance the sky selectively, but rather adjusts the Luminance of the low red components areas of the picture. You can adjust this method to the more blue-selective by modifing the channels extracted from the picture: extracting yellow or orange (instead of red) is more blue selective but also as a lesser effect. rather work with the limiter mask (a bit a feathering and anti-aliasing work great here to reduce hard lines in certain cases).

[bstreeck]

Ok, so the limited formatting allowed in these posts has destroyed the hierarchy of the Layers:

Possibly this would have made it more clear, as the spaces that were there have fallen together:
> Sky Enhancer (Group) [Luminance Blending]
> + Limiter-Mask
> + Green-Mask
> + Blue-Mask
> + Red
+ Picture

See the workshop picture for a clear graphical layout of the layers.