What visual perception does and what photography should do

Visual perception is a highly complex process that integrates many intricate individual processes to create an impression that is wonderful for us. But why do we perceive visually at all? Why do we see? Other creatures, such as mice or moles, successfully make their way through life with extremely simple visual abilities. Is our ability to see only an addition to enable us, as most would reply glibly, to recognize other people, to choose an adequate partner, to procure food, to read or to orientate ourselves? Most likely, this isn’t the case, as these abilities are merely a small part of the overall purpose of perception. The superior goal is the acquisition of information, of knowledge about our environment. Compared to hearing, feeling, smelling and tasting, seeing is the most effective way to achieve this important goal. Moreover, by perceiving color or the facial expression of our counterpart, it opens up sources that would otherwise remain closed to us.

So far, so good, but seeing is difficult because the data that reaches us is constantly in flux and not constant. The brightness of an object changes with the light intensity. If it doubles because the sun comes out from behind a shading cloud, the amount of light reflected from the thing also doubles. The situation is similar in terms of color. Even if the light intensity remains the same, sunlight’s spectral composition changes throughout the day. In the morning and evening, for example, it has a greater red component than at noon, and parallel to this, the wavelength mix reflected from the objects also changes. The shape of things is determined by the angle from which we view them. When we move, their retinal image changes. A right angle can become an acute one, and the chair in front of us becomes a distorted image. The same applies to the size of the object. When we increase the distance to the large oak tree in the garden, the retina’s image decreases by half, and vice versa.

If all these changes actually penetrated into our conscious perception, things would be multiform, ambiguous and difficult to define. Our lives would be correspondingly complicated and laborious. Perhaps even impossible to cope with. To prevent this devaluation of seeing, the visual system must limit itself. Instead of mapping and forwarding everything, the visual system should actively focus on a limited number of object properties. These are those that remain constant under all circumstances, or at least most circumstances, and are thus resilient enough to enable the brain to categorize things. In this regard, the only valuable knowledge is that of an object’s characteristic and permanent properties. It could also be called its „true nature“ and this is what the apparatus in our head is looking for.

Information about the invariant properties of objects is the only one worth collecting for the visual system.

Let’s run through these requirements for the above-mentioned problem areas. To perceive object brightness, the relative reflectance properties of the objects and object parts are more important than the absolute amount of reflected light, which remains constant regardless of incident light intensity. With the help of lateral inhibition and the center/surround organization of some retinal and cortical ganglion cells, the visual system has built a strong system that blocks out changes in brightness across large areas and instead focuses on differences within smaller areas. We also call it brightness constancy. We also recognize a very similar formation of ratios in color perception. In this channel we find cells that determine the relation between reflected and irradiated wavelength content. Because a cherry or a tomato always reflects most strongly in the long-wavelength red region of the spectrum, let’s say at 650 nm wavelength, we can attribute this property to them in this way independently of the spectral composition of the incident light. This is what we call color constancy. Shape constancy arises because we construct the appearance of things according to fixed rules. Some of these rules are as follows: Straight lines in the retinal image also appear straight in the object perceived in three dimensions. Line ends that coincide in the two-dimensional image also do so in the three-dimensional one. More intricately, we perceive T-shaped line connections as points where outline parts overlap. With this set of construction rules, we are basically able to transform changing ambiguous retinal images into stable perceptions, so that a chair always remains a chair when viewed from different positions. Remains the object size. Since the image of things on the retina is a central perspective projection, it must inevitably change with distance. By taking into account the likewise changing angle of vision, which results from the position of the eyes to each other, the visual system can counteract this becoming smaller and larger and provide us with size-constant perceptions.

So, after so much theory, what do we take with us into the night? I believe the photographically relevant nectar lies in the fact that we can derive from the various constancy phenomena of visual perception a neurological rationale for something that can be read in any better book on image composition: „Look for the image behind the image in your subject and reveal its true character.“ If we adhere to our findings and the perspective articulated so brilliantly by Semir Zeki in „Inner Vision“ (Oxford University Press 2003), then our perception’s primary task is to sift through the multitude of ambiguous data, seeking patterns that reveal the true, unchanging essence of things. Photography should do exactly the same. A landscape may be a landscape, a mountain a mountain, and a face a face. But by using our creativity and empathy to try to discover a meaning in each motif that goes beyond the first impression and to preserve it in the picture, we create the real eye-catchers because we make the work much easier for our perceptive apparatus.

If we use photography as a medium of communication and not merely for documentary purposes, and if we want the message to be communicated to reach the viewer, we do well to respect the preferences of visual perception. Therefore, regardless of the message we aim to convey through photography, whether it’s our feelings about a particular object or an aspect of it, it’s crucial to keep it as distinct as possible from the overwhelming amount of information the image inherently contains. Therefore, we should strive to reach the „true core“ as deeply as possible and convey it through the real motif in the picture. The further we penetrate (the better the extraction succeeds), the more impressive the image will be perceived by the viewer (see Adams, Weston, Cartier-Bresson). In many books on image composition, there is something about giving your images „substance“—yes, you have to. Because this substance is nothing else than the clearly communicated true character of the motif, and „clearly communicated“ means „easily accessible for visual perception“.

The head behind the camera must listen to all its perceptual channels in order to recognize the essence of the subject. – He must see with all his senses! However, our burden often impedes our ability to access this overall impression. Everyday things, small and large worries and distractions, block the gates, so that perceptions only trickle in or no longer reach our consciousness at all. 

The ability and possibility to access the true character of objects is opposed by various hurdles within ourselves and in our external world. First of all, the sheer amount of information that hits us prevents us from grasping what it is really about. We have to deal with so many visual stimuli, sounds, smells and tastes at any given moment that our perceptual apparatus has to block out most of it just so we don’t get out of balance. Once it is achieved, we avoid everything that could endanger the order and stick to the so hard-won stability. Only by fading out do we lose a lot of information that would be important to recognize the actual connections lying behind the sometimes false reality. Secondly, the categorization of all impressions resulting from the familiarity with the objects is opposed to a truly free view. Children are not yet aware of this issue, and they freely visualize the truly important things in their drawings. But already in school, this freedom is taken away from them by teaching them the obviously more important skills of reading, writing and arithmetic. Consequently, they lose direct access to immediate sensory experience. The naming of objects with learned names takes its place. And the older we get, the more automatically and quickly we catalog and categorize everything in our environment. So we recognize everything, but we don’t really see anything anymore, as Frederick Frank put it so well. Thirdly, there is the burdening of the consciousness with the small and large worries of everyday life. The demands of the professional world have increased so much in recent years that many people can no longer really escape them, even on vacation. Children, if they exist, often provide worries all their own. And if you’ve made it to the field with your camera bag, despite time constraints, lack of practice with old equipment or new gear may bring additional distractions.

Getting these hurdles out of the way can be very difficult in some cases. Relaxation techniques for body and mind can help, and targeted avoidance strategies for coping with everyday life are also useful in some cases. Of course, there should be an intuitive understanding of the recording technique and the equipment. Most importantly, however, is to be aware of the hurdles and, while working to overcome them, purposefully reserve those moments for photography when you feel truly free and able to drop all preconceptions about what is out there in the world.

A period of time when one can often experience this freedom is the first few days after returning home from a trip or vacation. For this short duration, one is detached and relaxed enough to see everyday things at home in a whole new and completely different way. One notices otherwise overlooked details and recognizes their importance. Certain light situations penetrate the consciousness, making the familiar surroundings appear exciting and new. Familiar objects suddenly reveal previously unknown or overlooked characteristics. In short, the freedom we acquire on the road allows us to see as we should always see, a freedom not present in everyday life. Unfortunately, everyday life often takes us back too quickly and obscures this ability.

Once the difficult step of opening the mind and recognizing what the subject expresses or what its true nature is, it is up to the photographer to transport this into the picture. Photography is a visual language, and the commonality of all languages is to communicate thoughts and feelings through abstract symbols. The symbols of our medium are pictorial elements, such as shapes and forms, their orientations and sizes, movement or the absence of it, the shape of space. All of them together are represented by luminosities and colors, which collectively we also call tonal values. To use them correctly, we must know their perceived meaning; one could also say „felt“ meaning.

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Main Image creation, Depth and Size

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