I go to a fair amount of science fiction conventions. One of the things I do while there is shoot photos of what's going, usually of people in costume.
Last weekend I attended my first Dragon*Con. It was amazingly crowded and a target rich environment for a photographer.
Unfortunately, though the crowds made some of my normal convention tricks, such as carrying an umbrella or softlighter on a light stand around - like I did at ConCarolinas for the shot below - completely impractical.
I tried going with the shooting rig I've been using at school events, a 550EX on a flip bracket with an E-TTL cord. While it was better than straight on camera flash, it quickly became obvious that it was going to too heavy a rig to hang off my neck for hours at a time.
I also wanted more directionality and height to the light, and some way to fill in costume details in the lower parts of the body and the eyes and, especially in the areas of the convention where there were no handy low ceilings to bounce the flash. Extra height was important, as the short working distances necessitated wide angle glass and lots of semi-crouching to get photos non-distorted photos of folks from head to toe. As I got lower, so did the flash on the bracket, and the shadows stopped going where I wanted them.
My solution turned out to be ditching the bracket in favor of two flashes using Canon's Wireless E-TTL system. This, with the addition of a Honl gobo/bounce card and a Sto-Fen OmniBounce, and the occasional use of another person as a light stand, turned out to be a light, really flexible set up for convention photography.
I used it for indoor portraits with no bounceable ceiling:
Indoors with a bounceable ceiling:
Outdoor portraits with a volunteer holding the main light:
Wide-angle outdoor portraits, with volunteer:
Here's how it works:
One 550 EX is set up on the camera, with the omnibounce on it and angled up. This is the master flash, and in Canon land, it's in exposure group A. The omnibounce is there mostly to spew the communication prefashes around enough to ensure that slave gets activated.
The other 550 EX is set to slave move, and put in exposure group B. This is the main (key) light, and I generally held in my left hand, up and out, around a 45-degree angle. If there was a low, white ceiling, I put on on the Honl Gobo as a bounce card and bounced the flash off the ceiling. With no ceiling, I set the flash head to the 24mm setting and used it directly, either in hand, or by having a volunteer hold it for me. Quick note - getting your volunteers from among the companions of the person you're photographing is a good way to ensure you self-propelled light stand doesn't make off with your flash.
The ratio is set so that the main light (slave flash, group B) is pumping out more light than the on camera flash (master, group A). I usually went with a 4:1 or 6:1 ratio - the on-camera flash putting out 2 to 2.5 stops less than the main. This turns the on-camera flash into a weak, on-axis fill light that pulls out costume details and shadowy places in the face.
I used my camera in M mode, with shutter speed/aperture/ISO settings set to kill most or all of the ambient light indoors. Outdoors, I stayed in manual, but set the exposure to work with the ambient light.
The joy of this set up is the mobility of the main light. I'm right-handed, so it generally went left. But with a helper, it could go right, over just even more left, like here, where I'm using an assistant and bouncing the main light off the ceiling:
The main light can also go more interesting, places, like the floor, where it can provide appropriately evil dramatic lighting for a group of villains: