Summary: What a heartbreaker! Before ordering this TS-E 17mm f/4L, I checked all the review sites. None tested its performance when tilted. It looked good by the tests they did do. So I ordered it. The following results and observations are from testing the lens in carefully controlled conditions on two Canon 5D Mark II bodies. I have been using view cameras and/or tilt-shift lenses for over 30 years.