… for Random Weirdness
Tip #617: Benefits of a Tilt/ShiftLens
Tilt/shift lenses modify depth of field, perspective and focus.
Traditional lenses project a circular image onto a rectangular sensor to create an image. Normally, that circular image is fixed in its location to the sensor. However, a tilt-shift lens allows us to modify where that circular image lands in relation to the sensor.
By tilting the lens, you change the center of that imaging circle, which can straighten the lines that appear to converge in the distance. The camera body remains in the same position, but the tilt shift adjusts the lens’ perspective. That makes tilt shift lenses a big help for architectural photography. Walls that are straight may actually look crooked because of the lens’ perspective; tilt shift lenses can change that perspective, making those walls straight again.
Tilt shift lenses also allow for greater control over an image’s depth of field. Traditionally, anything the same distance from the camera as the subject will appear in focus—that’s because those objects lie on the same focal plane. On a normal lens, the focal plane is parallel to the camera. Tilt the lens, and the focal plane tilts as well, becoming a diagonal line, instead of one that’s parallel to the camera. This creates the appearance of a much deeper depth of field than shooting a traditional lens at the same aperture. With the focal plane as a diagonal, it’s possible to have two objects that are parallel to one another, with one item in focus and another not.
These lenses are also great for shooting panoramic shots. Here’s an illustrated blog, plus a tutorial video from CreativeLive that showcases tilt-shift lenses.