PBase

i was asked to be the photographer for a prom at a school. im not a pro, but i have some of the basic equipments. just the xti, kit lens, 50mm 1.8 lens, an extra battery, 3011n head and 808rc4 leg bogen/manfrotto, a 430ex flash with the pro gary fong kit.

the banquet/prom is at the field museum in chicago. it is mildly dark inside and i was hoping the fong kit will fill the room up with light.

would i need an umbrella kit or two? or will it be fine with what i have?

For a large space with flash,I find "Painting with light" an excellent remedy

I'd guess if you are walking about shooting table shots or candids, you may be somewhat OK. If it's the cattle call for couples shots, I'd suggest that you're behind the power curve in more than just light. Do you need to be sure you can deliver a good image for all the couples (etc.) to choose from? Do you have enough memory and storage to not need to risk re-using the same cards until you have verified copies? The 50/1.8 may do well for the "portraits" but may not be wide enough to do tables and casuals. I'm not sure an extra battery is enough, and extras for the flash as well - and redundant camera/flash gear.

I would strongly suggest you go there before the date of the prom and do some test shots. I'm sure that you will be able to find some combination of lighting, ISO and camera settings that will give satisfactory results. You would like to know what your equipment will do in that particular location before the pressure is on.