The Canon TS-E 45mm f/2.8 Tilt-Shift Lens brings tilt, shift and rotate movements to a digital (or film) SLR format camera body. In near-standard focal length, the TS-E 45 delivers excellent optical quality.
First, what is a Tilt-Shift lens?
Canon's Tilt-Shift lenses feature three not-found-on-a-typical-lens adjustments. Tilt, Shift AND Rotate. Large format system users are familiar with these adjustments, but many 35mm format users are not. These adjustments can be used individually or simultaneously to alter the relationship of the optical axis of the lens to the sensor (or film) plane.
Tilt. Turning the small (too small) tilt adjustment knob angles the lens up to +/- 8 degrees relative to the sensor plane. The result is a plane of sharp focus that is not parallel to the sensor plane. The plane of sharp focus follows the direction of the tilt of the lens. For example, tilt the Canon TS-E 45mm f/2.8 Tilt-Shift Lens downward to keep an expansive area of relatively flat ground in focus from close out to infinity even at a wide aperture setting. Actually, the plane of sharp focus becomes more like a focus wedge as the DOF (Depth of Field) increases with distance.
Use this feature to selectively keep objects in or out of focus in the picture. A very diffuse background can be produced with this lens opened wide to f/2.8 and when tilted significantly. Diffusely blur the non-subject portion of your picture to dramatically direct the viewer's eye to the subject. The tilt adjustment scale is marked in 1 degree increments. The amount of change in plane of sharp focus at the maximum tilt settings is significant.
Shift. A shift adjustment moves the lens sideways parallel to the sensor plane. The effect of shift is perspective distortion - either correcting or enhancing as desired. The uses for this functionality are many. Shifting enables sides of tall buildings to be made parallel - instead of converging lines. Shooting highly reflective objects can utilize lens shift - the camera can be positioned outside of the reflection for the shot while the perspective remains as though it was shot straight on. Stitched panoramic photos are easy to make with the Canon TS-E 45mm f/2.8 Tilt-Shift Lens. Simply take multiple images of the same scene (without moving the camera), shifting the lens between shots. Are you unable to get the shot from the proper position because of an obstacle? Simply move to the side and shift the lens to give the perspective you wanted from the blocked position.
Rotate. Even though not designated as a feature in its name, the Canon TS-E 45mm f/2.8 Tilt-Shift Lens can also rotate. A small release unlocks the up-to-180-degree rotational movement of the TS-E lenses. Detents are provided at 30 degree increments and positive locks are provided at 90 degree increments. The small release lever takes a little getting used to, but the rotation function is very valuable.
These 3 adjustments are both functional and creativity-inspiring.