using my own design) but they are still the best commercially available diffuser for the MT-24EX. The only negative things I can say about them is that the front plastic is a little too opaque, and that if you're using the MP-E 65mm above 4x it's difficult to get light on the subject due to the angle between the diffusers and the subject (using the Canon flash mount that comes with the flash). Good light quality "out of the box", and even better if you do a little experimenting.
For many years I struggled to get good light out of Canon's MT-24EX. The flash heads are small, there's really no built in diffuser, and in order to get good diffusion and short flash durations (to help freeze motion) the flash heads need to be as close to the subject as possible. So the trick has always been how to diffuse the MT-24EX in as short a distance as possible when it's practically a bare bulb flash. In the end I resorted to using a combination of diffusion plastics, and I turned my flash into something only Doctor Frankenstein could love.
Now there's a new, commercially available, diffuser for the MT-24EX made by Mr. Ian McConnachie available via eBay. They are the best diffusers I've ever used for the MT-24EX in terms of size and diffusion quality, and on a scale of one to Martha Stuart I'd give them a nine. Really well designed! The image I'm including with this post is not an "out of the box" example since I am adding additional diffusion material inside the diffuser, but it does represent a worse case scenario for the MPE-65mm since I'm shooting at life size (the diffusers are at their maximum distance from the subject, and the apperant light size principle is working against me). Even so the diffusion is really good! The specular highlight on the right edge of the dragonfly's eye is normal, and simply due to the angle between the flash head and the subject. You'll notice that there is color and texture behind that specular highlight -it's not completely blown out and that's what you want. At higher magnifications the flash heads get even closer to the subject and the diffusion gets even better.
As an extra added bonus the modeling lights on the MT-24EX are still usable, although the light output is a little reduced because it has to pass through the diffuser. It hasn't been a big deal for me since my own diffuser designs for the MT-24EX have worked in the same way so I'm use to it.
Here's an instruction video by Mr McConnachie showing how to assemble and attach the diffuser:
Disclaimer: I have received no financial compensation for this blog post, not now nor in the future. I'm providing this information solely because I know that there are people out there who are still struggling to get good light out of the MT-24EX...
Update: After I ordered a second set of Ian's diffuser (wanted a set to experiment with) he refunded my money. He didn't have to, and I didn't ask. I like his diffuser so much that I was willing to purchase two sets out of my own pocket. I did, however, pay full price for the set that I reviewed for this post.