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A simple diffuser for Canon’s MT-24EX macro flash

The views expressed are those of the author and are not necessarily those of Scientific American.

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My standard macro kit costs several thousand dollars (camera, $1800; lens, $1000; flash, $600; various accessories, $300). Yet, most of what I consider the more unique aspects of my style are down to a mere few cents of tape, paper clips, and plastic diffusion.


The effects of bare flash (top) and diffused flash (bottom) to photograph a harvester ant. The equipment used to take both images is otherwise identical.

A homemade diffuser inserted below the flash heads makes a sizable difference. To my eye, the second image is miles better than the basic, out-of-the-box flash photograph. Diffusion softens and spreads the light, eliminating glare and allowing us a more detailed look at the ant’s texture.

My decidedly low-tech diffuser is a double-layer of Rosculux tough white diffusion clipped via cardboard to a plastic collar made from a milk jug.

Canon 7D camera, MP-E 65mm 1-5x macro lens, MT-24EX macro twin flash, and diffuser.

A closer look at the device, partially unclipped and happily filthy from field use:

To understand why a diffuser imparts such a significant softening effect, consider the perspective from the other end of the camera. Here is how an ant sees my gear with and without the diffuser:

The diffused light is soft, expansive, giving the impression of a cloudy day.

As one final modification of the twin flash, I have raised the heads an inch above factory standard. Why? The extra distance allows the cone of light to fall across more of the diffuser’s surface. This spreading effect is apparent when the diffuser is viewed from above:

Once you learn to recognize this setup as reflected in the shiny cuticles of my little subjects, you’ll know just how much I rely on it. See?

A fire ant gazes back at my twin flash diffuser.

addendum: There are more ways than one to diffuse the twin flash. I love looking at the various contraptions created by others:


Alex Wild About the Author: Alex Wild is Curator of Entomology at the University of Texas at Austin, where he studies the evolutionary history of ants. In 2003 he founded a photography business as an aesthetic complement to his scientific work, and his natural history photographs appear in numerous museums, books and media outlets. Follow on Twitter @myrmecos.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. Sean McCann 5:03 pm 03/4/2013

    Thanks for teh inspiration. I really need to work on my diffuser system now.

    Link to this
  2. 2. arachnojoe 6:10 pm 03/4/2013

    This is helpful, thank you. But I have a question. My understanding is that using a diffuser requires that I increase the light output, and that increasing the light output actually increases the duration of the flash rather than the flash intensity. And the more we increase the duration of the flash, the longer the effective exposure and hence the more the image will blur from movement by the subject or by my jittering hands when handheld. The MT-24EX won’t go any faster than 1/250sec. Do you have any suggestions for dealing with the need to increase the brightness or for dealing with the apparently consequent image blur? I have to do most photography handheld, with subject that often only sit still for a second at a time (spiders, of course).

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  3. 3. mattcole 8:37 am 03/5/2013

    Nice post Alex and thanks for the mention of my twin-flash diffuser.

    I do like seeing all of these home-made solutions but I’m still surprised that there is still no effective commercially available diffuser for the MT-24!

    Matt Cole

    Link to this
  4. 4. Alex Wild in reply to Alex Wild 9:22 am 03/5/2013

    Matt- I’m also puzzled by the inadequacy of the commercial diffusers for the MT-24EX, and why Canon doesn’t offer one since the flash is unusable bare.

    Joe- Yes, blur is a serious issue with the MT-24EX, especially above 3x when the flash is near full. I resolve the issue by shooting at ISO 200 and 400. Since the newer cameras have more acceptable noise at those settings, I can save on batteries and the motion blur is less of an issue.

    Link to this
  5. 5. DRintoul 9:49 am 03/5/2013

    I don’t have the twin flash system, but I do have the Canon ring flash (MR-14EX). I can think of no good way to diffuse light from that device, but if someone here has done that, I’d appreciate hearing about it.

    Link to this
  6. 6. arachnojoe 12:56 pm 03/5/2013

    Thanks Alex. I don’t think I’ve ever played with ISO. I guess I better try making sense of it.

    Link to this
  7. 7. orionmystery 11:41 pm 08/21/2013

    Thank you, Alex.

    Have you tried using Vellum paper for diffusion? I can’t get it here in Malaysia but a few of my friends have tested it and the result was really good! Not water resistant though.

    Link to this

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