Ok, so here's the deal. I've been tasked at my staff retreat this year to photograph the group of about 35 people indoor in an extremely poorly lit environment. I have one speedlight; an Altura AP-C1001 ETTL that I rarely use because I don't take many portraits (of humans) and I tend to stick to macro or landscape. I don't really want to invest in a lighting set-up for something I'll do once a year, but really want to get good results to impress. I shoot with a Canon 50D and will be using my Canon 10-22mm wide angle. I plan to shoot elevated with a wireless shutter release cable. Given my horribly lit scenario here and my one speedlight; without buying a bunch of lighting equipment I wont use more than once a year...what options do I have to photograph this many people? I'm willing to spend $80 tops here for whatever I need. What do you suggest?? Thanks in advance!!