It's just that the T/S features do not allow for accurate metering (when T/S is used) and you have to stop it down before the lens movements are applied. But this is why this lens is actually easier to use on a digital body because you can chimp, then adjust exposure if necessary.
"Due to the obtrusiveness of both the mobile ramps for shift and tilt, and the mount, there seems to be no room for aperture communication with the body, so it is completely manual. Once pre selected in the aperture ring, a button needs to be depressed to close the diaphragm iris down. Although this does not seem agreeable in this day and age, it is completely understandable given the characteristics of the lens itself and its mount. "
