I have 10gb of memory in CF cards (2x 1gb, 2x 2gb & 1 4gb). Is that enough to shoot RAW for a 4 hour session? This includes pre-ceremony, ceremony and reception. Outdoor wedding and with 200 guests if that matters. I'm thinking 400-600 is a good range. I'll only be chimping to check exposure, WB and shutter speed. No erasing photos at the event. Thanks in advance.