It's as simple (and ridiculous!) as it looks - length of ducting, with a flash stuck in the end. I've added a CD in the other end as a reflector to try to even the light out a little.
And here it is 'in action' - the bottom half of the frame is the same image, but with the exposure dropped -4 stops in ACR to show the hot spots a little better. You can see how uneven the light is, with 12 o clock to about 4 o clock being lit, but a lot of falloff after that
On this shot, I added a second (hand held) slave flash - you can see that this even things up a lot (same idea as above - bottom half is dropped 4 stops in ACR). This looked pretty good, so I thought I'd see out some willing 'models'... Cue Eeyore and Elmo:
Eeyore looks OK - very 'flat' lighting, but he doesn't have any reflective eyes (aaw, poor Eeyore!) so you can't see the trademark ring catch light, and he's quite a big guy, and was a fair distance off the wall, so you can't really see the ring shadow/halo against the wall...
Elmo, however, is lucky enough to have real (plastic) eyes, and looks a lot better with the ringlight - you can see in the catchlight that the light still isn't even, but it's a lot better. Still need to try to mask off some of the ring around the flashes to try and even things out, and maybe figure a way to mount the 2nd flash (or better, get the reflection working well enough that the 2nd flash isn't needed)
That's gonna be tomorrows problem... or next weeks. Sometime.