How tilt-shift lenses work.
Tilt-shift lenses have two sets of knobs: one that controls the tilt function and one that controls the shift function.
The Tilt knob changes the plane of focus by tilting the lens in relation to the sensor. This means your focal plane, which determines the area in focus, isn’t parallel to the camera’s sensor but rather is angled in a certain direction.
Once you’ve tilted your focal plane, you can use selective focus to either broaden or narrow your depth of field. You can create a very shallow depth of field with lots of lens blur or you can bring everything into tack-sharp focus. You can also make two points at different distances from your camera in focus.
The ability to manipulate focus with the Tilt function is due to something called the Scheimpflug principle. One way to see this in action is with miniature faking photos, where you can make real-life scenes look like a miniature scale model by blurring most of the image and shooting with a very shallow depth of field.
The tilt effect alters the focal plane of the image, but the shift effect alters an image’s perspective. With the Shift knob, you can move the lens up and down or side to side on the body of the camera. As the lens moves, the image plane moves too, so that the sensor records different areas of the total image. You can think of it capturing a panorama without the need to physically move the camera. To use the Shift knob, point the camera lens where you want the image to begin and twist the knob to shift the lens in whichever direction gets you your desired composition.
“With any lens, a circle of light hits your rectangular image sensor,” explains photographer Nick Ulivieri. “But with a tilt-shift lens, the image circle is a lot bigger than a normal lens. So when you shift, you’re moving the image circle around your sensor. Think of it this way; what you see through the viewfinder is only a fraction of what the lens sees; it's as if you were cropped into a photo in Lightroom. Shifting the lens, then, is like dragging the crop box across the image to find the ideal composition.”
This panoramic-type function enables you to capture completely straight lines no matter where you’re positioned in relation to an object. One of the most common examples of this is in architectural photography, where tall buildings will appear to fall backwards the higher they go. With the Shift function, you can get perfectly parallel lines all the way up.
How to correct perspective with photo editing software.
One way to use your tilt-shift lens is to make a panorama by taking one picture, shifting the knob upward, taking another photo and stitching them together in editing apps like Adobe Photoshop. “Stitching images is a huge part of my workflow,” says architecture photographer Andrew Pielage. “I overlap about 30% of every image to ensure that I get a proper stitch.”
You can also correct perspective in the Transform panel in Adobe Photoshop Lightroom. These tools work by stretching or compressing areas of your image, which will crop your image to some extent. This works for many images, but if your image has a lot of distortion, the crop could lower your image quality or alter your composition. Post-processing tools are good solutions for many scenarios, but for professional photographers or enthusiasts who need perfect results on location, a tilt-shift lens is the best way to get the shot in-camera.
Five ways to use tilt-shift lenses.