Neil van Niekirk's
Tangents blog site has amazing lessons on using flash.
Tangents - photography by Neil van Niekerk
Flash CAN be bounced off of walls and ceilings,even in very large, high-ceilinged venues, but it is tricky, and demands HIGH ISO settings most of the time, like 1600 to 6,400 ISO, and zooming the flash head to long, telephoto beam spread angles AND precise aiming of the flash beam....that is a technique originally called "
foofing", popularized by famous wedding shooter Denis Reggie. That method became popular only when Canon and Nikon had introduced capable high-ISO d-slrs back in the 2007 period. The thing is this: for foofing, the camera's ISO level absolutely MUST BE ELEVATED HIGH for this to work the way it is supposed to; Neil V gave a nice talk at
B&H Photo some months back, and he confronted this issue of ISO bias among the majority of amateurs, people who have this outdated, irrational fear of moving the ISO off of base-level settings like 100, or 200. In large venues, successful flash often demands
very high ISO levels when using speedlight levels of flash power.
When shooting bounce flash, I begin at 400,500,or 640 ISO, and move upwards from that starting point; my camera is ISO 100 base, but I never shoot bounce flash at 100 ISO; bounce flash has a loooong way to go many times, so elevating the ISO to at least 500 to start makes sense. This is a *****critical****** secret to being able to shoot effective speedlight bounce flash shots in large venues: start with the ISO set to a value that is at least two, or three full EV levels higher than the camera's base ISO value.
Second--get a Nikon SC-28 or SC-29 TTL remote cord for the flash, which allows you to shoot flash off a flash bracket, or with an assistant holding the flash, or with the flash held in your left hand and aimed high and angled down and across the face of people for group shots and grip-and-grin stuff. Moving the flash off the camera, but connected by the Nikon TTL remote cord changes the angle the light hits the subject from. Here's a close-up shot I did using SB-800 on SC-28 TTL cord, and just moving the flash around and actually SEEING the shadows as I fired with thew flash at low power. Once I found the position to hold the flash, I shot several frames of this, with the flash at about the 1:00, and LOW in relation to the plate. This shot would have been impossible with the flash in the hotshoe.
You do not "need" a remote trigger; cheap 10-,15-,and 20-foot cords can be bought at FlashZebra.com. Multiple Nikon SC-17 or SC-28 or SC-29 cords can be successfully daisy-chained together; I sometimes use an SC-28 and an SC-17 connected together and that gets me about 8 feet of off-camera distance with somebody aiming the flash for me, and stretching the pigtail cords out fairly tautly.