hi, i just got a rebel xt, and now i want to get an ac adapter so that i can connect my camera to my macbook and leave it for two days taking pictures out of my window. What kind of adapter do i need, i just ordered the CA-PS 700, but the seller told me i may need the dc coupler dr400 or dr700, but then my friend told me i should need either or, does anyone here have the same camera? if so which one do i need? or do i even need one? i ve searched for a coupel of hours and could not get a straight answer..thx in advance guys