I have some experience shooting weddings and would like to shoot them professionally. I have a Nikon D70s and have a major problem with exposure. Many of my images have blown out highlights (often as a result of shooting group formals under direct sunlight). Many others (often during indoor reception) are underexposed and have a lot of shadow and midtone noise. I use a Sigma EG-500 adjustable flash and often try to bounce it to avoid harsh lighting/shadows etc. How can I make sure my exposures are within range? I use the flash to fill under direct sun, but I still end up with blown out whites which are unrecoverable even in ACR. This requires major editing in post-production to ensure high quality images, and many rejected photos. Please help.