One question I receive in my workshops for beginners is about flashes. Particularly “What the heck is this for?”
And, “Does it actually do anything?”
Not all flashes have these two items that cover the flash head and pull straight out, but if yours does and you’ve always wondered, here is your answer.
Those two items both serve different purposes. The one that flips over the flash itself is a diffuser. Its job is to spread out the light from the flash. You might have seen larger diffusers, such as a softbox over a flash. Those diffuse even more light than this piece of plastic. But it actually is better than nothing when it comes to spreading out light. At the same time you flip out this contraption, your flash will typically back up the light source inside of the flash unit (if it has zoom capabilities) to help project a wide swath of light.
These two actions work hand in hand to spread light and not make it so tight on your subject. The last piece of plastic, the more opaque one the at sticks out straight, helps bounce light that would have bounced away from the subject, get pointed back just a liiitttle bit more towards your target. This can be helpful when even more diffusion is wanted, or if the flash is being bounced off a ceiling and some catch light is wanted in the subject’s eyes.
Let me show you the difference a diffuser, coupled with the bounce plastic and a wide zoom in the flash, can make.
This first shot of a f-stop Gear Satori pack I was reviewing is taken at 85mm and a distance of about eight feet. This shot is taken with the flash pointed directly at the pack and coming in from the left side as I have tilted the camera, as I did not want to bounce the flash against a colored wall and couch.
Notice the harsh shadow to the side of the pack caused by the flash? This is because the flash is coming from the side and is relatively close. That shadow is caused by the pack being another eight feet from the wall behind it (as your subject gets further from the background, the shadow will increase).
Now let’s try it with the diffuser in place, the bounce in place and the flash zoomed back to 14mm (all of which happens automatically when I pull out the diffuser).
The exposure settings on the camera are exactly the same in both photos. The difference should be clear, that the second shot has much lighter shadows as well as a softer light on the pack itself.
The impact of this method is less pronounced when zoomed in further and the flash is now positioned above the camera in a horizontal orientation. Can you tell which shot is which in these two examples?
The clue is in the slight change in the quality of light. Because the diffuser’s light is not as intense as the straight flash, it allows in a bit more ambient light and this can be seen in the first image as a slight more orange is showing (from the overhead tungsten lights). The reflections on the buckle are also slightly less harsh.
Using this quick and easy diffuser which you will never leave at home can have its advantages. It’s not mean to replace a true softbox, but it will help when one is not around.