Blur, Layers and Blending Modes, a Magic Mix in Photoshop, Part 2

Continuing our exploration of Layers, Gaussian Blur and Blending Modes, Part 2 takes a more complex approach.
So what do we do if the basic approach doesn’t give you what you want.

Variation 1 – Lighten the image first

By lightening the image first, before the duplication step, we avoid the darkening of the image that happens as a consequence of using Multiply.

1 – The original image

2 – Duplicated and Multiply blending mode, the image is quite dark

3 – Going back to the starting image, I lighten it by using levels and adjusting the midpoint slider so the image is lightened without clipping

4 – Now when we duplicate and change to Multiply the image is less dark but has the desired appearance

5 – now the blur gives us the image we want

Variation 2 – Select what we blur based on tonal range

Some of the traditional blurring techniques only blur the highlights, for example. We can duplicate this by using masking on the blur layer. You can start with either the straight technique or the lightened initial image. Which will work best will depend on whether you want the blurring in the highlights (lighten first can help) or the shadows (no lightening).

1 – Our starting image

2 – Duplicate the layer. For this case I set Blending Mode Overlay

3 – Blur the top layer. Notice how not only the highlights have blurred but also the shadows.

4 – By double-clicking on the layer icon in the Layer Palette we bring up the Layer Styles Dialog. Now while we normally see this when we have a special layer style applied, like a drop shadow, it also has some great functions when there is no such style applied. The feature we are going to use here is at the bottom of the window, the Blend If Gray This Level slider. What this does is allow you control how much of this layer blends based on its tonal range. The sliders has black and white sliders. And if you Option (Alt) click on a slider you can split it into two parts, which define where it starts to fade out and has completely stopped contributing. It takes longer to describe than to try, so grab an image of yours and give it a go.

5 – The resulting image

You can equally well preserve the effect in the shadows and tone it down in the highlights by splitting the white highlight slider and setting it to give the result you want.

Below are some more examples:

Here we work on restricting just the shadow blur
Straight Effect