What’s a rim light, and when and why should I use it in my sci-fi art?

Jennifer Malvern, US

Mark replies

Rim light is a light source placed behind your main subjects. It’s most commonly used in photography and films, where the focus is on one or more characters in front of a darker background. The back light creates a outline of light around the character or portrait, which frames them and separates them from the background.

I’ve noticed that rim light has become overused in concept art and illustration, but it’s definitely an effective useful lighting technique to use under appropriate lighting conditions. Its origins are in standard three-point lighting in portrait photography and other visual mediums. A photographer places three main light sources around the subject to obtain the most amount of visual information possible: the main light; the fill light that’s essentially an artificial bounce light of the main light to show details in the shadow areas; and the rim light to add details to the edges and frame of the scene. I would advise using rim light if you’re keen to enhance the details in your character’s silhouettes with framing, and if you’d like to separate them from the background.

Note that rim light isn’t just about the actual lighting conditions, but also about creating a certain mood. It works best if you want to create the feeling of suspense and mystery, or simply exaggerate the visual intensity of your image.

Rim light can strengthen the visual impact of your images. Use it to frame the main subject, and to bring back more details in the silhouettes.

It’s easy to achieve a mysterious effect with just pure rim lighting, but be careful: without a main or fill light you may not be able to show your character as clearly as you want.