September 12th, 2011
Contrast masking is a technique which boosts the dynamic range of an image by revealing more detail in shadow areas and recovering some detail in the highlights. It is a technique that was used traditionally in the darkroom but now with software such as photoshop we can replicate digitally. It works best in photographs where the dynamic range of the sensor is being pushed for example the image shown here.
To achieve this the first step is to open the image up in photoshop and duplicate the layer (ctrl+J)
The next step we need to desaturate the duplicated layer which you can do by selecting Image>Adjustments>Desaturate (Ctrl+shift+U)
and now invert this layer Image>adjustments>invert (Ctrl+I)
This creates a black and white negative of the image so everything that was dark is now light and vice versa. So now all we need to do is select the overlay option in the layers drop down menu to apply the effect to the original image.
The effect is a little ugly at the moment as the edges of the image has halos and the image itself appears a little flat. This is fixed by selecting Filter>Blur>Gaussian Blur and choosing an amount anywhere between 10 and 70 there is no fixed rule here whatever works best.
To finish up you can adjust the contrast and saturation or make and levels or curves adjustments that you like. Experimentation is the key.
Final Image Before