I'm prepping for an interview this weekend. We're shooting near a historic building, and want to use the image of the building (as seen through a hotel window) as the background. Our tentative plan is to shoot on a T2i with a 2.8 lens (we'll have zooms, so probably on the 70mm range to blow up the background). We're aiming to shoot at f8 so the building is in focus (it's about 1km distant). In order to get our exposure right, we're going to ND9 the window, and use a pair of daylight heads for the interview subject (Jokerbug 800 bounced off a card for fill, Pocket Par with Chimera close in for key). And we'll add tungsten heads daylight balanced for background and backlight as needed. Am I on the right track? Do i have enough punch for this exposure?