The lens optical axis and film plane center are alignment and the optical axis is vertical to the film plane in case of ordinary lenses. If relation between the lens optical axis and film plane is changed, special effects on images can be obtained. For example, if the optical axis is changed not vertical to the film plane or the plane of focus is swung not parallel with the film plane, the range of focusing can be controlled to deep or shallow focus without changing aperture. This operation is called "tilt", which is achieved tilting the front part of the TS-E lenses. Shifting of the optical axis from the center of the film plane makes it possible to correct or enhance perspective distortion. This operation is called "shift" . It eliminates the tapering off of the building to make a natural expression of the images in the picture, correcting perspective distortion. "Shift" is achieved by shifting the front part of the TS-E lenses. Before Canon TS35mm f/2.8 S.S.C. introduced in 1973, "tilt and shift" operation was possible only with large format cameras. Canon also introduced three TS-E lens series with auto iris by EMD. The TS-E series lenses are the only interchangeable lenses at the time for 35mm SLR cameras, which have tilt-shift operation with fully-electronic automatic diaphragm control system.
