Q: Will the VerteX™ work when there are no nearby walls or ceiling off which to bounce light (outside, in sunlight, for example)?
A: Yes, we emphasize bouncing light off nearby objects, as this is the only way to produce the largest, softest light source from a small external camera-mounted flash. The mirror(s) help to redirect light at its maximum intensity for the most efficient bounce. When there aren't any nearby objects to bounce, then the white diffusion panel(s) may be used to soften the light somewhat. Without ceiling, walls or nearby objects to bounce the light, however, it's simply impossible to avoid harsh shadows with a camera-mounted flash. Even increasing the size of the white diffuser panel to three or four times its size will not eliminate the harshness of the light. Outdoor daytime conditions often call for the full power of direct flash in order to offset the effects of the sun. No diffuser should be used in this situation. So while the VerteX™ may not help here, it also does not interfere, as it can be easily moved completely out of the way without having to remove it from the flash head.