What Big Mike is talking about is what I was talking about earlier: experimenting to find a really pleasing, good bounce method. I once was shooting some maternity nudes in a large bathtub filled with green bath-salt-colored water in a small bathroom with a big tub. The room was only about 8x6, but with a high ceiling of around 10 feet, and a three foot "separation wall" coming down from the ceiling and separating the tub from the remainder of a large,long bathroom. Normal forward-facing bounce made awful light. To the left was a big picture window covered by a cool, lavender-ish fabric blind, and that was out of position and sent cool,lavender light away from the subject. The tub was a Jacuzzi-type, big,deep,and oval in shape. Bouncing off the back wall was too close and over-shot the subject. I kept rotating and clicking the flash head around. Finally, I zoomed the head to Maximum tele, concentrating the beam, and firing about 3 feet below the ceiling, to my left and backwards. The light went up, caromed off the wall, and then hit the basically 8 x 6 foot x 3 foot separation wall and made a HUGE "light box" that was extremely soft due to the 48 square foot "enclosure" located only about 9 feet from the subject!!! it also created beautiful diffuse highlights on the surface of the green-tinted water. The quality of the light began as BAD, then got better, and then finally after about 20 test shots, with "just the right" combination of beam concentration, unusual room construction with the 3 foot "deep" wall "divider" that kept all the light within the "mixing chamber", I had the equivalent of a huge light bank at my disposal.
One of the biggest issues when doing straight-up bounce flash is the tendency sometimes for saw hot, raw light to blast out of the very sides of the flash head, and strike the subject directly, and cause a very unattractive "hot stripe". With really, really powerful flash units like the Metz 60-series potato mashers or the Sunpak 622 Super, there can be some MAJOR, major problems when the flash is bounced and any part of the Fresnel lens is even remotely pointed toward the subjects!!! This can happen even with less-powerful flashes like Nikon's old SB-16, with which the hot,raw, untamed light that escapes right at the edges of the Fresnel lens can be a real PITA at times. The solution is normally to make SURE that the face of the flash's Fresnel lens is not angled toward the subject, but definitely angled away. THe closer you are to the subject, and the more-powerful the flash is, the bigger this problem is.
Another tool that can really help avoid this hot,raw light from moving directly to the subject is to use a "flag", like the Honle brand "wraps", which are dark fabric with Velcro to hold the wrap in place, and to "flag off" stray light. Anyway....bounce flash...it can be done a lot of ways. I just want to emphasize that the degree of ZOOM used can,at times, be a huge make-or-break factor, and there are times when it is best to use a white diffuser cap, like a Sto-Fen or the Canon or Nikon factory-supplied ones as shown in Kundalini's photos, or lacking that, sometimes it's good to use the flash with the built-in 14mm ultra-wide-angle diffuser pulled down and into position, to spread the light as widely as possible. Other times, "foofing" (Google it), using telephoto zoom flash and bouncing off of distant or very high ceilings/walls and using elevated ISO's of 1,000-3,200 can be just what the Dr. ordered.
