Since it is now Spring (just barely here in Vermont) I thought it would be good to write about the proper use of a diffuser. For those of you who have suffered through one of my tiresome workshops you have probably seen me demonstrate diffuser use but for those of you who haven’t here goes.
A diffuser is nothing more than a semitransparent piece of nylon held rigid by a flexible frame. When placed between your subject and the strong light of the sun the diffuser softens the light (it diffuses it) creating far more appealing light for photography. Indoor photographers use diffusers all the time to create beautiful portrait light but they are usually very large and would be impossible to use outside. Outdoor photographers often use two kinds of diffusers- one that is shown here that you can buy and the other that is better know as a cloud. Not that digital kind of cloud, I’m talking about a regular old cloud that is up in the sky- the kind that softens the light when it gets between your subject and the sun.
Most people use a diffuser improperly outside- they hold it too far away from their subject. They do this because it is almost always the easier and more comfortable way to hold a diffuser. The problem is that when held too far away the light created by the diffuser is no different than the light cast by the shadow of your body.
How could this be? If you remember from High School physics class, light falls off at the square of the distance it travels. This means that the diffuser loses its ability to create beautiful soft glowing light very quickly as it is moved farther from the subject. Hold a diffuser 4 feet from a flower and then cast your shadow on the subject and there will be no difference in the quality of the light. But if you slowly move the diffuser in toward the subject you will notice the light getting better and better until it is the best when it is almost on top of your subject.
When I am out photographing wildflowers in bright sunlight I always use a diffuser to soften the light (soft delicate subject- soft delicate light). I have large 32″ and 42″ diffusers that I use because I can hold them easily with my hand when I am close to my flower or I can easily prop them up when I am too far away. If someone is helping you by holding your diffuser make sure that it is as close to subject as possible- just outside your viewfinder.
The photo of the trout lilies was taken on a bright sunny day. The soft light was created by a diffuser.