“If you don’t have a tilt-shift lens to shoot cityscapes or architecture, to get perfectly rectilinear shots you’d need to position your lens parallel to the ground and perpendicular to your subject,” explains Ulivieri. But most of the time, you won’t be parallel to the building; you’ll be on the sidewalk looking up at it, and you’ll mostly likely need a wide-angle lens to fit the whole building in the frame.