Bill,
To help get more softness from frost on a frame, try this:
Build a 4 sided box out of foam core, say 3′ by 3′. I would use black on white foamcore, black on the out side and white on the inside – this will cut down on reflection issues. Fit it with a 1″x2″ frame on the inside about 6″ from one end. Staple a peice of 216 (250, opal, gridcloth, users choice) to the 1″ frame. Lastly, mount a baby plate to the outside of one of the sides. Use this to attach to a c-stand (you might need to use 2 if it’s too heavy). Aim it at your subject and shine a light through it!
There you have it, a cheap soft box. The white foam core will help diffuse the light while the box will help to direct the light. It may not be the most portable, but what do you want for a few bucks?
Good luck!
Rick Amundson
Producer/Director/DP
Screenscape Studios
Bravo Romeo Entertainment
http://www.screenscapestudios.com
http://www.bravoromeo.com
http://www.indeliblemovie.com