Please explain the use of a diffuser on a beauty dish

<p>Hi<br>

What I specifically want to understand is what does a diffuser sock does on a beauty dish. As the light source is not becoming any bigger, my logic tells me the light is not getting any softer. But am I missing something? How does a sock make the light softer when the light source is staying the same size?</p>

<p>Thanks</p>

<p>Geoff</p>

<p>Geoff: It's about directionality. True, the light source doesn't get bigger when the sock is on, but when the sock's there, the light will still "wrap" differently around a subject that is <em>suitably close to the dish</em>. The sock turns the dish into a two-foot softbox, which means that when it's up close to, say, a person's face, some light that would have (for being directional) gone right past the face (leaving shadows) will now find a path <em>to</em> the face, filling those shadows and rendering a different-looking shadow transition. The farther away the subject is from the dish, the less you'll notice the difference.<br /><br />With a technique roughly as sophisticated as fingerpainting, I have done this fabulous still-drinking-my-coffee illustration that I hope conveys the concept: </p><div></div>

<p>Think of a window light coming into your living room. The light is soft but when you hang a white sheet over the window the light becomes diffused and much softer. The window did not get any bigger but the light scattered in all directions and caused a much softer light.</p>

<p>one more example. think of a flashlight, the beam is directional and you can see the beam of light. If you put white diffusion over the light the beam turns into a soft flood of light.</p>

<p>A white reflector will have the same effective emission pattern as that "dish with sock" example.<br>

The only difference is that using a sock reduces the umbra caused by the central gobo that blocks direct light rays from source. The umbra is useful in cosmetic photography when the model's face is close enough to the light to be within the umbra and reduce exposure on the forehead and upper part of the face.<br>

When you pull the subject far enough from the light to be outside the umbra, the sock reduces the light level but doesn't do much else.</p>

<p>Thanks very much guys. I knew it had to do with the scattering of the light, but your explanations were awesome. Thanks very much.</p>

<p>When it comes to this kind of question, a picture is worth a thousand words.</p>

<p>Fot those that think there is little or no difference, have a peek : -)</p>

<p><em>One note, when using a diffuser the difference is more dramatic if the Beauty Dish is silver and you use a white Nylon Diffuser. </em></p>

<p>Opps, here's the picture:</p>

<p> </p><div></div>