The last time I brought a ringflash it was pretty cheaply made, was it's own flash unit and died before the year was up. But then I saw this ring-box which requires a shoe-mount flash for it to work, and since I was already getting the Metz 64, figured hell why not. The TTL does work thru it (Cuz well... it's thru the lens), but course the flash itself will give the red LED since it's own sensors would claim a misfire since it's blocked by the ring box. It's intended for DSLR, but seems to work with my E-P3, just keeping in mind, smaller lens are going to be more cumbersome to use because you can't wrap the center of the ring box around the lens to hold support it between the camera and the flash, but with most of my adapted lens or the Sigma 60mm f/2.8 with the hood on (the hood actually acts as a stopper for the elastic bands going forward a little) it works alright. You *can* use a smaller lens like the 45/1.8, but you have to sort of support the ring box a little more by getting your finger around one of the elastics. Also since the E-P3 is shorter than a DSLR, you have to angle the flash up like a bounce a little into the little hole in the back. Some quick shots with my E-P3 (Manual Mode) + Metz 64 set on TTL + Vello Ring box These three with the Olympus 45mm f/1.8 (all three at 1/160 @ f/1.8, ISO 200, though if I did it again I'd probably go f/2.0 or 2.5 to get the nose in when I'm getting that close for effect): E-P3    ---    45mm    f/1.8    1/160s    ISO 200 And two with the Sigma 60 f/2.8, giving a little more distance: 1/180, f/2.8, ISO 200 1/180, f/2.8, ISO 200 It's fun... but it's also probably intimidating to people when you're carrying it around since we're looking at an 18 inch diameter opened up, that's also about 7 inches thick from front to back.