I have a Nikon D80, and I have been asked to do an outdoor engagement session for some friends. I am a newb so I need some help! What mm lense(s) would be good for this? I assume they will want some full body pictures, as well as head shots of the two of them. I have a 17-70 3.5-4.5 and a 50mm 1.8 I am thinking between these two lenses, and especially with the 50mm prime, I should have it covered. But is there anything else that would be really handy? A different prime maybe? I want a 100mm macro lense, would it come in handy for this or not? Should I get a telephoto zoom/prime? Remember, my camera is digital so it has the crop factor to consider.