Colour Saturation

This technique demonstrates how to saturate colours in Lab mode without introducing noise that the 'normal' Hue/Saturation adjustment does. I am not suggesting that you use so much saturation - I always put the Saturation adjustment into a Layer and then change the Opacity to reduce the effect.

Here is a comparison of a 200% screen shot of the two methods...

Original		This image was run through NeatImage, even though it was taken at 100 ISO
Normal Hue/Saturation adjustment at +40		Notice the extra noise, colour distortion and abrupt steps in colour. The Red-ish end has turned grey and extra Yellow has appeared.
Lab Color Mode - setting the Levels of the 'a' and 'b' channels to 55 and 200		This is much smoother with every colour being saturated equally.

Convinced? If so then run my Action or follow these steps to get the vibrant colours without increasing contrast etc.

1 Duplicate the Image : Image>Duplicate...

We never want to over-write the original and also we really want to create an adjustment layer as the end result of this method. Then working with the new image...

2 Convert to Lab Colour : Image>Mode>Lab Color

Lab Color gives much better control over colours since it separates colours from lightness (the 3 channels are Lightness, A and B). In RGB mode, the lightness is included inside the Red, Green and Blue channels.

3 Apply Levels to channels A and B : Image>Adjustment>Levels…

Select the A channel and set the black and white points to 55 and 200, then repeat this for the B channel before clicking OK.

Or you could use a Curves adjustment layer instead - permits a bit more latitude if you need to adjust things a bit, especially if it introduces a colour in balance because you didn't quite get it right earlier on in your work flow.

4 Convert back to RGB : Image>Mode>RGB Color

And then copy this image back over the original one (in a new Layer). You can then delete the duplicated image you created in step 1.

5 Adjust Opacity to suit

You can now alter the Opacity to reduce the effect to the level you want.

As I use this effect quite a lot, even with only 10% opacity.