The Hinge Rule involves three planes positioned relative to the camera lens. As long as the orientation of the camera rear (film plane) remains

unchanged, the three planes used in the Hinge Rule must intersect along a fixed spatial line — the hinge line. The distance between the lens and the hinge line, denoted as J, depends solely on the amount of lens tilt applied and the lens focal length.

Neither the distance J nor the position of the hinge line is affected by normal focusing movements of the camera rear. Since the plane of sharp focus must pass through the hinge line per the Hinge Rule, this plane is constrained to only one motion when the

camera rear is focused: it can only pivot about the hinge line. As the camera rear is adjusted, the plane of sharp focus rotates like a seesaw

swinging on the hinge line. The angle of the plane of sharp focus is determined by both the position of the camera rear relative to the lens and

the Scheimpflug Rule.

The perpendicular distance from the lens to the plane of sharp focus is the required distance J. Given this distance and the focal length of the

lens in use, the required lens tilt angle is determined by:α = arcsin(f/J) This angle is most conveniently found from lookup tables, such as those included with view cameras; it can also be calculated fairly easily with

a scientific calculator.

For focal length f in millimeters, distance J in feet, and angle α in degrees, an approximate simplified formula is:α ≈ f / (5J) The following diagram illustrates what happens when the lens is tilted about a horizontal axis passing through the lens center. Starting from the

neutral position where the lens plane is parallel to the film plane (zero tilt), the lens is tilted forward in 2‑degree increments. The plane of sharp

focus also begins parallel to the film plane, then tilts in the same direction as the lens plane tilts. The degree of tilt of the sharp focus plane varies considerably and depends primarily on the position of the camera rear standard. The effect is

most pronounced when the camera is focused at infinity. The behavior is perfectly symmetrical for upward lens tilt: tilting the lens upward or

downward from 0° to 10° produces the same amount of rotation in the focus plane. In both cases, the plane of sharp focus rotates in the same

direction as the lens plane.

Some view cameras feature base tilt instead of (or in addition to) axis tilt. That is, the front standard of the camera can tilt around the camera

base or monorail, rather than pivoting about the center of the lens. On cameras with front base tilt, tilting the lens forward not only angles the lens downward but also extends it forward. This changes the plane

of sharp focus compared with conventional axis tilt: the plane not only rotates, but also lies closer to the lens than it would with axis tilt. When the lens is tilted upward with base tilt, the plane of sharp focus shifts away from the camera while rotating. This behavior is asymmetrical

compared with the effect of standard axis tilt, as shown in the following figure.

In the past, photography books tended to suggest that photographers use rear standard tilt to adjust the plane of sharp focus. This is because

the operation is simpler and more predictable. Furthermore, a basic understanding of the Scheimpflug Rule alone is sufficient to estimate the

required tilt angle. However, using rear tilt introduces image distortion, causing vertical lines to converge inward. It is therefore recommended to keep the rear

standard perfectly vertical unless perspective distortion is intentionally desired for creative effect. The following diagram illustrates what occurs

when the camera’s rear standard is tilted relative to the lens.

The figure below illustrates what happens when the camera base tilts backward toward the rear of the camera. In the case of front standard tilt, forward tilting of the rear focus plane pushes the focus plane away from the camera.

Rotation of the front or rear standard of a view camera about the vertical axis is commonly referred to as swing. Swing is entirely analogous to

tilt, but it is almost always of the axis type. To understand the action of swinging the lens to the right (viewed from behind the camera), refer again to the figure above and imagine looking

down at the camera from a top-down perspective. When looking down onto the lens from above, the motion of rear standard swing follows the

same principle shown in the previous diagram.