Assuming lens axis front tilt, here are the trade offs in choosing between a small degree of tilt (say less than 3) and a larger tilt: A small tilt causes a wider or fatter wedge but one that is far off axis from the cone of light seen by the lens. Conversely, a large tilt (say 10 degrees) makes the wedge more aligned with the lens view, but with a narrower wedge. Thus, a modest tilt is often, or even usually, the best starting point.