Here's a do-it-yourself contraption you can build that combines the characteristics of a snoot and a softbox. It consists of 2 nested tubes. In my prototype I made the inner tube from a length of scrap mat board about 4 inches wide bent into a cylinder and taped in place. On both open ends I taped some white tissue paper to serve as double diffusion. This diffusion drum was then rolled into a large tube of black paper about 24 inches wide. The whole thing was about 10 inches in diameter. A flash is fired in one end and diffuse light is sent out the other.
The device has a few interesting characteristics. When up close to the subject it provides nice even diffused light. The inner diffusion drum can be slid within the outer cylinder to change how much hood is exposed beyond the diffuser. This can control how fast the light falls off around the edges. The net result is a nice soft light that falls off quickly around the edges, sort of a spot diffuser.
