Perspective in Photography

Preface

Perspective is the illusion of depth on a two-dimensional flat surface so that the image appears more natural and realistic. It is an integral component of Architecture, Painting and Photography.

In the past, and in different cultures, different approaches to perspective have been applied. However, its foundation, as we understand it today, took place in Renaissance Italy. This was no coincidence. The concept of perspective expressed the humanistic character of the Renaissance. From that moment on, the new point of view and the new center were the eyes of the human observer.

This blog aspires to present the following topics:

What is perspective?
What are the types of perspective.
How we achieve each kind of perspective photographically.
Perspective and frame composition.
How to do perspective correction:
- Digitally
- With Tilt-Shift lenses

About perspective

Perspective is a concept that is often used incorrectly, so it is best to give a proper definition:

Perspective is the technique of projecting a three-dimensional image onto a two-dimensional surface (paper or screen) and creating a sense of depth to it.

This sense of depth is created by lines converging at points of intersection called Vanishing Points.

Thus, the closest objects to the viewer appear larger than the most distant ones.

Perspective and sense of depth on a flat surface

Human vision is based on the projection of objects upon the retina, which is a two dimensional surface. Therefore empirical perspective, the way people perceive space and the objects within it, has much in common with the above definition. In fact, human vision is more complex than theoretical perspective, so the latter functions only as an approximation.

Camera lenses are divided into several categories. One such distinction is between lenses corrected for the verticality of the lines (Rectilinear), where the straight lines of the photographic object are projected as straight upon the camera sensor, and fisheye lenses (Curvilinear) where the straight lines of the photographic object are projected as curves. The vast majority of photographic lenses are Rectilinear.

Rectilinear lenses, depending on the way they are used, can depict perspective with one, two or three vanishing points.

One vanishing point
Two vanishing points
Three vanishing points

Perspective with 1 Vanishing Point

The three-dimensional space consists of the dimensions of width, height and depth.

In 1 Vanishing Point perspective the height lines remain vertical, the width lines are perpendicular to the height lines, and the depth lines converge at 1 Vanishing Point:

In photography, when capturing buildings, 1 vanishing point perspective is achieved by holding the sensor absolutely parallel to the facade wall:

Camera and 1 vanishing point perspective

Examples:

Perspective with 2 Vanishing Points

In 2 Vanishing Point Perspective the height lines remain vertical, the width lines are no longer perpendicular to the height lines and converge at Vanishing Point 2, and the depth lines converge at Vanishing Point 1.

In photography, when capturing buildings, 2 vanishing points perspective is achieved by holding the sensor absolutely parallel to the vertical edge formed by two perpendicular walls:

Camera and 2 vanishing points perspective

Examples:

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Perspective with 3 Vanishing Points

In 3 Vanishing Point Perspective the height lines stop being vertical, converging at Vanishing Point 3, the width lines are no longer perpendicular to the height lines and converge at Vanishing Point 2, and the depth lines converge at Vanishing Point 1.

In photography, when capturing buildings, 3 vanishing points perspective is achieved by rotating the camera up (usually) or down around the horizon axis:

Camera and 3 vanishing points perspective

The following perspective is also considered to be a 3 points one:

It is achieved as follows:

Examples:

Perspective and Frame Composition

Perspective in photography can be perfectly combined with composition rules.

Composition is the conscious process of deciding which visual elements to include and how to place them in a photograph in order to create a harmonious frame and a pleasing image.

The application of such rules can make our photos stand as more interesting.

Perspective and Leading Lines

A very useful rule is the leading lines, which lead the viewer's eye from one part of the composition to another. Usually, they start from the bottom of the frame and guide the eye upward, from the foreground of the image to the background. The direction lines can be anything: rivers, tree trunks, lines in the sand, hedges, etc. They can be harmoniously combined with the appropriate choice of perspective.

In the photo above , 1 Vanishing Point Perspective was implemented. The road acts as leading line directing the viewers gaze towards Mount Olympus (main subject).

In the photo above , 1 Vanishing Point Perspective was implemented. The tiles act as leading lines to the statue (mainly subject).

Perspective and Rule of Thirds

A very common rule is the rule of thirds. An imaginary grid of two vertical and two horizontal lines is applied to the frame.

It is recommended that objects of interest to be placed upon the grid lines or upon their intersections. The idea is to place the subject outside the center of the frame. This eccentric placement creates a more dynamic and interesting image.

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In the photo above, 1 Vanishing Point Perspective was implemented. The road with the sidewalk act as direction lines. The horizon was placed near the bottom horizontal line of the grid. The light pole was placed on the right vertical line, while the women on the left. The Vanishing Point was placed at grid point 2.

Perspective and Frame within a Frame

Another rule is the frame within a frame. The first frame is the literal border of the photograph. The second frame is created within the image, exploiting visual elements in the scene to border the main subject, further drawing the focus to it.

In the right photo, 1 Vanishing Point Perspective was implemented. In the left photo, 2 Vanishing Points Perspective was implemented.

Perspective & lens focal length

The convergence of the lines to the Vanishing Points becomes more intense as the focal length of the lens decreases, i.e. as the lens becomes wider.

The photo on the left below was taken with a telephoto lens, while the photo on the right was taken with a wide angle.

Perspective Correction

Many times, in order to fit a subject (usually a tall building) into the frame, we have to rotate the camera upwards, resulting in a three Vanishing Point perspective. Thus the vertical lines cease to remain parallel to each other and converge at the 3rd Vanishing Point. It should emphasized that the 3-point perspective is not something negative. It's a matter of personal preference.

In the event that, for aesthetic reasons, we decide that a 3 Vanishing Point Perspective is not desirable, we can return to a 1 or 2 Vanishing Point Perspective in the following ways:

• Digital editing with keystone correction in CaptureOne, Lightroom etc.

• Using a tilt-shift lens

Perspective Correction Digitally

The keystone function is present and works similarly in a plethora of digital image processing software. It provides the possibility of vertical, horizontal or total correction.

From the photos above it is concluded that digital correction crops a large part of the photo. The bigger the correction, the bigger the crop. The only way to mitigate this drawback is to rotate the camera upwards as little as possible and to leave enough space around the subject. This can be achieved by taking several steps back, while taking the photo.

This technique does not, in situ, ensure the final result, which becomes visible only after digital processing, and many times it can end in failure. For a successful outcome, it requires excellent knowledge of the optical field of the lenses used and, of course, a lot of practice.

Perspective Correction using a Ttilt-Shift lens

The use of a tilt-shift lens allows a real time perspective correction, via the shift function. The way this lens functions is exemplified in the following photos: