The basic design and construction is no problem. I have the lens - a fresnel page magnifier - I have the basic design - I will use my DIY softbox concept, but I'll make a long, narrow version. http://www.nikonians.org/forums/dcboard.php?az=show_topic&forum=154&topic_id=35505&mesg_id=35505&page= The main questions have to do with the target focal length. I have an 80-200, and a 1.4x TC. Do I set the lens so it fills the frame at 200mm and let it go at that? I haven't come up with a good idea for making it adjustable, although if that's the hot ticket, I could probably figure something out. FWIW, zooming the flash head does not change the size of the projected light by much when firing through the Fresnel - it just changes the shape of the "beam" from round at 24mm to sharply rectangular at 85mm. Have not been setup to see if it impacts the light intensity, but I'll check that out before the project is finished.