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Saving $500 – a DIY macro flash diffuser

Mayfly photo - macro photography by Terry Sohl

Mayfly, taken with my do-it-yourself macro flash unit. This was taken well after sunset, with the modified flash unit providing all lighting.

I’m now about 3 weeks into the macro world.  One thing that became obvious pretty quickly is that with such a short focusing distance (often about 1 foot from the subject), controlling light can be a lot tougher with macro.  Flash is an obvious way to control the light for a shot, but the “standard” flash units for DSLR’s generally aren’t good for macro, at least not with the flash right on the hot shoe of the camera.  For example, I have Canon’s “Speedlight” 430 EXII, a very nice flash unit.  But when it’s on the camera itself, there’s no way to direct the flash to such a short focusing distance.

You can buy a cord and take the flash off the camera itself, but to me it’s a little unwieldy to try to manage an off-camera flash and the camera itself.  Canon does make a specific flash for macro.  It’s a ring-flash, a round flash that goes right on the end of your lens.  It’s a nice solution!  It’s also $500!! Given that I’m still new to macro, I didn’t want to spend that much on a dedicated macro flash, so started looking around on the web and saw people have made all kinds of do-it-yourself flash setups for macro.

Better Beamer Photo

The basic Better Beamer setup, a simple pair of frame pieces and a Fresnel lens that attach to your flash with Velcro. I used the frame pieces of one as the basis for my modified macro flash.

It’s the opposite problem of when I shoot birds, and when I want to “extend” my flash a longer distance.  For birds, I have a “Better Beamer”, a simple yet very effective attachment to the flash that uses a Fresnel lens to focus light from the flash for a longer distance shot.  I actually had an extra bracket pair for my flash, so started wondering if I could use a modified Better Beamer setup for macro flash.

The idea…I just wanted something that could redirect the flash output.  The minimum focusing distance on my Canon 100mm 2.8L IS macro lens is a about a foot, so ideally I wanted something that would direct the light towards a very close object, but could also be used for a little bit longer distances (say 1 to 3 feet) that you might use for larger macro subjects like butterflies.  With a little aluminum foil, tape, and foam core board, I ended up making a surprisingly effective and easy to use macro flash setup.

Do-it-yourself macro flash

This is the basic modified Better Beamer components. The top is enclosed with foil-covered foam core. Another foil-covered foam core piece is positioned within the frame, directing the flash downward. The Better Beamer itself is also foil covered on the inside (OK, and outside because it was easier!) to better reflect the light from the flash.

I started with the Better Beamer frame pieces themselves.  They attach to the flash unit with Velcro, so it’s very easy to add or remove the Better Beamer setup.  What I needed was to direct the flash downward, towards a distance of about 1 foot from the lens.  I started by cutting a piece of foam core to fit exactly on the top of the flash unit, between the Better Beamer frame, and layered it with with aluminum foil.  This basically encloses the top of the ad-hoc macro flash unit.  With the top enclosed, I then wanted another foil-covered foam-core piece to fit within the frame, but at an angle that would direct the flash downward towards a subject about a foot away from the camera lens.  With the modified Better Beamer on the flash unit, and with the flash on the camera, I calculated a rough angle the piece would have to be at inside the frame, cut a foam core piece to fit, covered it with foil, and put it in place.  I also covered the Better Beamer frame itself with foil.  With this simple setup, the “normal” flash goes into the semi-enclosed unit, and is deflected downwards towards a close subject.

After trying it out, I was thrilled with the results!  For macro shooting in natural light, you often need a well-lit, bright subject or you won’t have enough shutter speed to get a sharp photo.  With the flash, I can make the flash the primary source of light, and given the very short burst of light from a Canon Speedlight, shutter speed itself isn’t as important and you can “stop the action” and get a crisp shot fairly easily.  With the flash set in the 90-degree position, with the flash pointing straightforward, the angle inside is perfect for bouncing flash towards a subject close to minimum focusing distance.  For a bit of a longer distance shot, the angle deflects the light downward too quickly, but with the 430EX flash, you can tilt the flash unit upward.  It’s thus very simple to use for a range of macro distances.  While the initial shots were very well lit and sharp, I made one more modification to diffuse the light from the flash.  With the simple bounce set-up, with the flash light deflected off the aluminum foil, the shots were well lit, but sometimes a bit contrasty and harsh.  I wanted a simple diffuser to soften the light, so just took a piece of thin white cloth and stretched it across the bottom of the modified flash setup.  It worked wonderfully to avoid the harshness of the un-diffused flash.

DIY Macro Flash Diffuser

The final piece of the puzzle, a bit of white cloth stretched across the bottom of the unit. The flash must pass through the cloth, diffusing the light and providing a more pleasing image.

Very simple, took me perhaps an hour to put together, and it saved me $500!  No, it’s not as elegant as Canon’s ring flash.  In fact, it’s definitely the ugliest piece of camera equipment I now have!  But it’s worked wonderfully, as I get to keep the wonderful ETTL (electronic “through-the-lens”) flash metering of my 430 EXII, and with the Better Beamer frame as the base, the modified flash components are easily removed when I’m not shooting macro.

I do suspect that if I keep up my interest in macro, that I will give in and get the ring flash unit some day.  But for now, my DIY macro flash diffuser is working quite well.

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