Accessory Flash Diffusion


Even if you have only one flash unit at your disposal, you can create stunning imagery if you plan your attack in a logical fashion.

We know, of course, that large, broad light sources will deliver an even spread of soft light. These sources are almost always large softboxes or umbrellas and, while there is definite value in having studio equipment available, here are a couple of ways to approach beauty and glamour photography with minimal equipment.

You will need to have an accessory flash with some power behind it. To be as accurate as possible, you’ll also need a flash meter. The flash will need to be set to manual mode; when it’s in auto or TTL mode and is aimed at something other than your model, it will limit the strength of the flash for either what bounces back from the subject to the camera or the amount of light that falls upon the subject. If you introduce diffusion or reflective material and aim the strobe at it, the strobe will read the light as it affects the material, not your model. The inevitable result is underexposure. Using the flash at full power in manual mode ensures consistent and measurable power output.

I keep an older, column-style Metz flash around for those moments when I need a small but powerful source. My model is the CT-2, expensive when it was purchased (and a real workhorse) but quite inexpensive now on eBay or through dealers that specialize in used

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equipment. If you decide to buy one of these units, inspect it first. You’ll want as clear (nonyellowed) a flashtube as possible. These units can be refurbished by the manufacturer, but it will add expense—and you’ll almost certainly have to buy a new battery too.

Of course, you can use a single studio strobe, even your camera manufacturer’s accessory flash unit (if it has enough power), in exactly the same fashion, as I’ll demonstrate with my old Metz unit.

First, and to demonstrate the difference between modified and unmodified light, I’ve set the Metz on a stand and aimed it at the model. I’d painted the wall behind her with a semigloss latex enamel to get a bounce-back reflection from the light. In manual mode, I metered the flash output, measured at her chin with the meter’s dome aimed at the camera, and set the aperture accordingly.

It’s not bad light. The only potential problem is the contrast of the flash, especially the nose shadow. I’d engaged a professional makeup artist for my model, so the amount of specularity on her skin from the flash is minimal. You may not be so lucky when your subjects do their own makeup, so you’ll have to take a close look at an enlarged LCD image (knowing that the LCD is not the final arbiter of exposure and contrast) and make a decision whether or not to send the client back to the dressing room for more powder. See image 6.1.

For my second setup, the flash was placed on a stand and positioned behind the camera, about 3 feet behind and aimed at the center of a 52-inch white Photoflex diffusion disc (see diagram 6A). Depending on the flash you use, you’ll have to do a little testing to find the optimum flash-to-diffuser distance. You’ll need to have the flash far enough from the diffuser to cover the material but not so far as to spill light on the subject or the background, at least within the image frame.

There’s a tremendous difference in “feel” between the two images I created. The first shot (image 6.1), nice as it is, is not nearly as soft as the second (image 6.2). The second still shows the bounce-back reflection, but the overall look of the light is more glamorous.

I wrote about accessory flash diffusion techniques more extensively in Christopher Grey’s Advanced Lighting Techniques, and I’d encourage you to check them out. If you typically work with a minimal gear set, you’ll want to try some of them. The results are terrific. Though accessory flash is inexpensive, working with it presents a unique set of problems. If you’re serious about shooting, you and your clients will be well served by your purchase of better gear.

Over the past few years, many manufacturers have made significant progress in creating modifiers for accessory flash units.While I still believe that no accessory flash (or any series of flash units slaved together) can take the place of studio strobes, I will admit that, when properly planned and understood, small units can do a good job within their limits. If you can live with long recycle times, lower power, and the difficulties and expense of trying to make them perform like something they’re not, well, bang away. Personally, I think your best bet is to buy a set of studio strobes, even of entrylevel quality. I think you’ll be much happier in the long run, even if your entry-level strobes are slightly inconsistent from flash to flash (which they almost certainly will be).

They say it’s a poor carpenter who blames the tools. I say a good carpenter avoids poor tools.

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