Quote Originally Posted by brucemuir View Post
Rise, fall & shift will definitely tax image circle but simple tilt probably doesn't but I'm not 100% sure.
Maybe someone knows ?
They will all require a larger image circle diameter. Think of it in 2D terms viewed from the side of the camera and draw a triangle from the top of the film to the centre of the lens, down to the bottom of the film then joining up back at the top of the film. The triangle represents a hypothetical image coverage of the lens.

Now tilt the lens. The triangle will also tilt. The triangle you have drawn or imagined will now not cover the whole of the film as it was only big enough to cover the exact film height.

Now do the same excercise but with a triangle with points a bit higher and lower than the top and bottom of the film and you will see that it is now possible to tilt the lens and the coverage triangle and still cover the film.