Soft focus effects are common in fashion and advertising images, but are not widely used for landscape photography. The landscape photographer is usually aiming to capture the sharpest possible image with the greatest depth of field, and using a soft focus filter would normally be counterintuitive.
However, in certain circumstances a soft focus treatment of a landscape can enhance the mood of an image by creating a soft glowing atmosphere, and can be particularly effective for backlit subjects. Soft focus is not the same as out of focus, and is not about degrading the image, but rather about subtly changing the image to convey a desired interpretation to the viewer.
The key to a successful soft focus image is to maintain a sharp rendition of the subject while adding a supplementary softer image. Traditionally with film this is achieved by use of patterned glass or plastic filters, by stretching a fine mesh over the lens, or less controllably, by breathing on the lens. These methods all work by allowing most of the light entering the lens to pass straight to the film while diffracting a small amount of light to give the desired effect. Of course this means that the decision to use a soft focus effect must be taken at the time the photograph is taken; with digital manipulation we have the luxury to apply a soft focus interpretation at any time, and to have much greater control than is possible using filtration with film.
As with most digital imaging manipulations there are several ways of achieving soft focus. The simplest and most direct method in Photoshop is to use a blurring filter (typically gaussian blur) and then fade the filter using a low opacity and an appropriate blending mode. However, because this process works directly on the image it is tedious to fine tune and cannot be altered after saving the image. A much better approach is to use overlays to create soft focus without modifying the underlying image. The examples below show the results of three different methods of applying soft focus through the use of overlays.
Soft focus
The simplest effect, the soft overlay, uses a duplicate image layer with the blending mode set to overlay. Applying a gaussian blur and then adjusting the opacity of the layer allows the intensity of the effect to be varied to suit the image. Since this method uses overlay blending mode the resulting image tends to have greater contrast and saturation than the original, but this can often give attractive results.
An alternative method, soft focus, is the effect generally used for portraiture and advertising images, and does not increase image contrast and saturation. This method uses two blurred images over the original, using lighten and darken blending modes, so that intensity changes added by the layers cancel out. Again the intensity of the effect can be adjusted by changing the degree of blur and altering the opacity of the two layers overlying the base image.
The third approach, soft filter, mimics the effect of using a soft focus filter on the camera. A desaturated and blurred copy of the image is overlaid on the original colour using lighten blending mode. Increasing the blur and opacity of the monochrome layer has the same effect as using a stronger camera filter.
Photoshop actions for these three methods can be downloaded by clicking the link below. The actions pause during running to allow the amount of gaussian blur applied to overlays to be adjusted to suit the image. Applying too little or too much blur will lessen the soft focus effect - try a blur of around 10 pixel radius to start with.
See the comments on the technical intro page if you are using a Mac.
