In most situations, photographers want the sharpest image possible. Thus, we have tripods, image stabilization, mirror lock-up, shutter releases, and so on. However, in some cases, it is desirable to deliberately soften an image. For instance, portrait photographers often soften their portraits to make the skin look more pleasing, and landscape photographers sometimes soften images to create a dreamy or romantic feel.
To achieve a soft focus effect, photographers use a number of methods. Some photographers use a soft focus lens. Others use a diffusion filter. Some place semitransparent materials, such as a nylon stocking, in front of the lens. I have even heard of some photographers spreading petroleum jelly on their lenses or filters. Luckily, digital photographers can leave the petroleum jelly at home as soft focus effects can easily be created in Photoshop.
To understand what a soft focus effect is, it is best to start by understanding the difference between a regular lens and a soft focus lens. In simplistic terms, the goal of a regular lens is to take a point, that is at a distance from the front of the lens, and focus the light from that point at a single spot on the film or sensor. This is shown in Figure 1. The important point in this figure is that all of the light rays are focused at the same point. This produces a sharp image.
Other methods of producing soft focus effects (such as nylon stockings, diffusion filters, and petroleum jelly) work by disrupting the light before it reaches the lens. This causes the light rays to focus at different points. As with a soft focus lens, this softens the image.
It is also possible to produce a digital soft focus effect during the editing of the image.
Figure 3 shows an image of an incredibly handsome gentleman (actually, that is my friend, Robert, and he made me say that or he wouldn't let me use the image). This image is a good start. However, the image can be improved by softening the skin.
Figure 4 shows the Layers palette for the image. The first step is to duplicate the Background layer by dragging the Background layer to the Create a new layer icon (shown in Figure 4). The new layer is renamed the Soft Focus layer. The palette after this step is shown in Figure 5.
The Soft Focus layer is blurred by launching the Gaussian Blur filter (choose Filter/Blur/Gaussian Blur). The Gaussian Blur dialogue box is shown in Figure 6. A radius should be chosen that blurs the image but does not completely destroy the detail. A radius of eighteen was chosen for this image. After the layer is blurred, the Blend Mode is changed to Darken (for more information on Blend Modes, see Blend Modes).
Obviously, the Gaussian Blur has softened the image. However, to truly understand what has been done in this step, it is necessary to consider the Darken Blend mode that was chosen for the Soft Focus layer. When the Gaussian Blur is applied, the local contrast of the Soft Focus layer is reduced. In other words, the darker colors tend to bleed into the lighter colors and the lighter colors tend to bleed into the darker colors. The blurred Soft Focus layer sits above the Background layer. When the Darken Blend mode is applied to the Soft Focus layer, any color in the Background layer that is lighter than the color in the Soft Focus layer above it is masked so that one sees the color of the Soft Focus layer instead. What this means is that the Darken Blend mode only lets the blurred effect be applied to the areas where the tones in the Background layer are lighter than those of the Soft Focus layer. The result of this is that the lighter areas of the Background layer are both blurred and darkened. However, the darker areas of the Background layer are less affected. At this point, the image appears as seen in Figure 7.
Next, the Soft Focus layer is duplicated by dragging it to the Create a new layer icon, and the Blend mode of the duplicated layer is changed to Lighten. The duplicated layer is automatically labeled as the Soft Focus copy layer. Again, to understand what has been done in this step, it is necessary to consider the Blend mode. When the Lighten Blend mode is applied to the Soft Focus copy layer, any color in the Soft Focus layer that is darker than the color in the Soft Focus copy layer above it is masked so that one sees the color of the Soft Focus copy layer instead. What this means is that the Lighten Blend mode only lets the blurred effect be applied to the areas where the tones in the Soft Focus layer are darker than those of the Soft Focus copy layer. The result of this is that the darker areas of the Soft Focus layer are both blurred and lightened. However, the lighter areas of the Soft Focus layer are less affected. The Layers palette is shown in Figure 8, and the image is shown in Figure 9.
Obviously, Figure 9 has too much blurring. However, before the blurring is reduced, the Soft Focus and Soft Focus copy layers are merged into one layer in order to reduce the file size. For this, the two layers are selected. Then, they are merged by choosing Layers\Merge Layers. The resultant layer is renamed the Final Soft Focus layer. The Opacity of the Final Soft Focus layer is adjusted to deliver the amount of softening that is desired. For this image, an amount of 35% is about right. The Layers palette at this point in the process is shown in Figure 10, and the image is shown in Figure 11.
The next step is to add a sharpening layer (we will protect the areas that were just softened from the sharpening layer). With the top layer selected, a new layer is created (click the Create a new layer icon at the bottom of the Layers palette) and the other layers effects are merged into the new layer (hold down the Alt key (Option key on a Mac); while holding down the left mouse button, select Layer/Merge Visible). This layer is renamed the Sharpen layer. This layer is then sharpened. The actual sharpening steps are beyond the scope of this article (for more information on sharpening, see Sharpening).
It is necessary to protect the softened areas from the sharpening. The easiest way to do this is to start with the mask that was created for the Final Soft Focus layer. The mask needs to be turned into a selection by clicking on the mask, right clicking the mouse, and choosing Add layer mask to selection (see Figure 15). The selection is now visible on the image (see Figure 16).
The selection is inverted by choosing Select\Inverse, and the inverted selection is applied to the Sharpen layer as a selection (with the Sharpen layer selected, choose Layer/Layer Mask\Reveal Selection. The Layers palette is shown in Figure 17, and the image is shown in Figure 18.
As a final step, the edges of the image are burnt. The steps of this procedure are beyond the scope of this article (for more information on burning the edges, see Burning the Edges).
The final Layers palette is shown in Figure 19. Figures 20 and 21 compare the original image and the final image.