Hands on: Add digital effects to images

Lighting is one of the most important factors in photography. Most of the time, it’s provided by the sun, but that’s not to say you can’t control it.

Making the right decisions about the relative positions of the camera and subject, as well as the time of day at which you shoot photos, can make the difference between a stunning image full of atmosphere and mood, or a lacklustre snapshot.

The problem is that the sun is not always willing to oblige. You may find yourself in situations where the sun is in the wrong place, or you are, or it’s the wrong time of day (or night) and unwanted shadows are everywhere. Indoor photography brings its own set of lighting problems, which are usually made worse by the standard solution – a flash unit attached to the camera.

The good news is that the magic of digital post-processing extends to lighting effects. Even if the lighting was poor at the time of capture, you can do something about it afterwards.

In this Hands On, I’ll explain how to do this using the lighting effects filters in Photoshop and Paint Shop Pro, I’ll show how to create your own lighting effects using an alpha channel, and look at a lighting effects plug-in that can bend light so that it wraps around 3D objects just like the real thing.

Photoshop sheds light
The picture, top, shows Photoshop’s lighting controls dialogue box, which is opened by Filter>Render>Lighting Effects. This box provides a lot of controls but, regrettably, there’s no live preview and the preview thumbnail isn’t really big enough to see the effect properly.

The Style pulldown menu provides more than a dozen predefined lighting setups. As they stand you probably won’t find them all that useful, but they do provide a good basis from which to start.

Three types of light are available – Spotlight, Omni and Directional. Omni, which shines in all directions from above the image, and Spot, which casts an elliptical beam, are definitely the most useful. Directional tends to cast fairly even illumination over the entire image.

You can reposition lights over or outside the image by dragging and dropping. The spread, angle and throw of the beam, indicated by an elliptical border, is adjusted using handles on the individual lights. Sliders provide control over intensity and focus, and lights can also be coloured.

As well as adding lights to the scene and changing their characteristics, you can define the reflective properties of the subject. Shining a spotlight onto a rug will produce a different effect to the same light shining on a car door or a tabletop. By using the four sliders in the Properties pane of the Lighting Effects dialogue box to control gloss, material, exposure and ambience, you can achieve a more realistic effect for specific materials.

The result depends as much on the ambient lighting and texture of the image as anything else. Pushing the gloss slider to its maximum shiny position and the material slider all the way to metallic won’t help you get a realistic reflection from a tartan rug, but with the right material these sliders can be used to good effect.

Another clever trick in the Lighting Effects toolbox is the texture channel. This allows you to select one of the image channels for use as a bump, or displacement map, shifting the image pixels by an amount and in a direction dependent on the greyscale value of the corresponding pixels in the bump map.

This has the effect of adding texture to the image and making it look even more like it has been directionally lit from a low angle. The final image uses the same lighting effects setup as the one immediately to its left, with texture channel applied using the green channel and an amount of 50.