It's not a complex technique and I got this result through a process of experimentation and trail and error and have since made a series of images using this, titled Bluescape.

Firstly I must dispel any notion that this particular image is a HDR as despite the fact that I am quite fond of using HDR for landscapes, I don't always depend on it for an effect and neither use it in this particular technique.

The effect I employed here isn't in itself that complicated while I do find the results quite pleasing.

Sometimes you can spend hours trying different combinations to achieve the desired result. Also for it to work you should have - a well exposed image with small dynamic range ie low contrast levels to begin with.

If you wish to try this yourself, more or less follow these steps:

1 - Darken the image by factor of 20

2 - Run it through the Solarize filter

3 - Remove all the colors, turning into B&W. (Sometimes I use desaturated here but other times as in this case it was a straight turn to B&W filter)

4 - Lighten the image by a factor of 20-40 (this depends on the initial exposure, density and dynamic range of the shot)

5 - Add Cyan and Blue

6 - Adjust as appropriate with desaturate, brightness and contrast controls.

7 - Check for noise and if needed run through a noise filter.