Adding colour and contrast to a flat image non-destructively

Fishin’ by the Bridge

I shot this on a fairly dull and overcast day, and the picture was lacking in some contrast and vibrance. I went to Photoshop and made a layer mask (Shift+CMD/Ctrl+N, overlay mode and filled it with 50% gray.

I added contrast by setting the foreground colour to white (X), selecting a brush with opacity about 15% and lightened the highlight areas in the foliage, grass, tree trunk and bridge, then reset the foreground colour to default black by CMD(Ctrl)+D, and painted the same opacity black on the layer mask in areas where I wanted the tones darker. 

Each new stroke of the brush adds 15% to the previous stroke. This method will only lighten light areas and darken dark areas, IE, if you paint white on black, it has little or no effect, which negates worrying about painting 'outside the lines'. Also it can’t add shadow where none exists, and the converse for highlights.

This fixed the contrast, but I still had flat colour, so I flattened the image, repeated the above steps but using a colour selected from the swatch corresponding to the area I wanted to saturate a bit more, like brown for the muddy banks, and tree trunks, green for the grass etc.

The good thing about using a layer in overlay mode, is that it doesn’t affect the underlying image the way just increasing saturation and contrast normally would, it adds no artefacts to the picture.

I learned this technique some time ago from a blog, but I fail to recall which one so I have to give credit to Mr Anonymous.