How We See Part 2: Gestalt Psychology

Today we delve a little bit deeper into the science of how we see and process visual information. This might get a little academic, but I promise we’ll be back to lighter stuff next week. Today we’re going to talk about Gestalt psychology and how it relates to retouching.

Gestalt psychology explains the way we innately organize our perceptions. When we talk about it, we often refer to the “unified whole”. In the simplest terms, Gestalt psychology states that “the sum of the whole is other than its parts”. (This is not precisely the same thing as the popular phrase “the sum of the whole is greater than its parts”, a mistranslation that is clarified by the originator of the phrase, famed Gestalt psychologist Kurt Koffka.)

What does this mean? Well, Gestalt psychology explains that our brains tend to see whole forms before recognizing individual parts. We even see whole forms that aren’t really there when individual parts form certain patterns. Let’s look at some simple examples.

Gestalt Reification Examples

In these examples, you’ll notice that your mind sees shapes that aren’t actually drawn in. They are only implied. This phenomenon is called reification. The triangle doesn’t exist. Nor does the sphere or the serpent or the rectangle. Our minds fill in that information for us. The actual elements of the images are cones or little Pacman shapes or abstract squiggles, but when arranged a certain way, we experience them as more complex shapes than they really are.

This is Gestalt psychology at work.

Another more practical example of Gestalt psychology might be the fact that you have a nose, a mouth, some eyes, some eyebrows, some ears, some cheeks, and a jaw. Separately those are just a random collection of parts, but put them together and you have a recognizable face, which incidentally you notice as a whole before you notice each individual part. Think about when you meet someone for the first time. Do you immediately notice the hook of their nose or the color of their eyes or do you first take in a general impression of their face? (Where this gets really interesting is when you look at Picasso or other cubist or abstract artists. At what point do things become recognizable and why?)

There are other visual principles of Gestalt psychology that are focused on illusions that trick our eyes or how our brains recognize objects regardless of orientation in space. If you’re interested in the topic, I recommend you delve further into multistability illusions or invariance.

To get a bit more technical, there are two fundamental principles of Gestalt psychology that we want to consider. There is the Principle of Psychophysical Isomorphism which simply states that there is a relationship between perceptual phenomena and brain activity. Then there is the Principle of Totality which states that our conscious experiences must be on a global scale, considering all parts of a whole simultaneously, because the nature of the mind demands that each component of a whole be considered as part of a system of dynamic relationships.

Ok, that’s a mouthful. What does this mean to us? When we consider a visual (either in life or in a still image) we are typically considering a unified collection of parts, or a “whole” (or in other words a group.) We are looking at a system of how smaller parts relate to one another, not necessarily pausing to linger on individual components. We are always influenced by the surrounding information for any given part. In other words, we focus on the larger picture, not the parts making up the picture. This does break down a little bit if we stare at something long enough, much like our second read on the above images is to notice that there are, in fact, no invisible shapes, but only little shapes implying something bigger. (We look longer and we notice the cones and the Pacmans instead of the sphere and the triangle.)

At its core, Gestalt psychology states that we organize our experiences in ways that are simplest, most orderly, and most symmetrical. Parts are many and sometimes chaotic. The whole is one simple thing because the whole tends to to be formed of orderly grouping structures. There are many ways (laws) in which we group smaller stimuli: proximity, similarity, closure, symmetry, continuity, good gestalt, common fate, and past experience. Here’s how some of those laws work. (Some are being excluded for simplicity’s sake because this article is a primer.)

Gestalt Law of Similarity

Law of Similarity – We group objects that are similar to each other. Here, objects are similar due to color and we see 6 groups rather than 36 dots.

Gestalt Law of Proximity

Law of Proximity – We perceive objects that are close to one another as groups rather than individual objects. Here we see 4 groups rather than 72 circles.

Gestalt Law of Symmetry

Law of Symmetry – It is pleasing to the mind to group objects symmetrically around a center point. We perceive these as 3 shapes rather than 6.

Gestalt Law of Closure

Law of Closure – Much like in our reification examples, the law of closure states that we see incomplete shapes as complete. Otherwise we would just see random dashes.

Gestalt Law of Continuity

Law of Continuity – We generally recognize the straight lines despite other input that might influence us to group in other ways, such as color change.

So what does all of this mean for retouching? When I retouch, I retouch with Gestalt psychology in the back of my head. Gestalt theory is something I learned in design classes, not photography classes or retouching seminars. It’s more about composition than anything else, but as retouchers, it’s our job to be creating pleasing, unified compositions. My goal is always to create one single pleasing whole. If I notice multiple competing systems (or groups) that compete with my ultimate final composition, that’s a problem. Competing systems can be certain kinds of stray hairs that form complete shapes, pores that form discernible grouping patterns rather than fading into subtle uniformity, lack of symmetry that might contribute to creating a less easily processed whole, etc. It also can work the other way for me in telling me what I don’t need to retouch. If there are gaps in lines, can I leave it alone because the shape is implied? This is particularly useful in determining how much work I need to do on a jawline. Color work also comes into play. Is something standing out that creates it’s own similarity aberration that makes it appear to be a separate whole? That needs to be toned down. Or it can go the other direction. Do I want something to stand out? I can use similarity grouping to my advantage. Always be aware of competing or harmonizing systems within your image and how all of the parts are interacting to build the whole.

The other way that I look at Gestalt psychology is a little more abstract. When we are with a person in life or when we first glance at a person or when we remember a person, we don’t see certain “flaws” the same way that when we first look at reification fallacy images, we don’t see the gaps or component shapes, but only the unified forms. Instead, we are biased to see a symmetrical, organized, pleasing whole. When we have time to stare at a still image closer, we can start to pick out the individual parts. This can mean picking out unattractive features we didn’t initially notice. I believe that we dissect visuals the longer we look at them. A retoucher can re-focus attention on the whole by cleaning up some of the parts or adding more parts to make sure that the still image whole is pleasing even upon close inspection. This refers back to my philosophy on making people look the way we may think of them in memory.

In the end, I’ll say what I always say. We aren’t looking to fix a person or change the essence of a product or place. We’re not looking for cheap tricks when we look at Gestalt psychology. We’re looking for greater understanding of how we see. In the end, we want to know how to make a person or thing look like a polished whole by knowing how the brain interprets visual data. Keeping Gestalt psychology in mind can help us do that by knowing the advanced design and psychological principles that contribute to a good, pleasing visual. Know how the eyes work. Know how the brain works. It will improve your artwork no matter what discipline you’re working with.

And again, if you’d like to learn more about how we process visual information, I really highly recommend this book. It’s part biology, part psychology, and throws in a bit of physics of light: (affiliate link)


How We See Part 1: Optical Illusions

In order to understand why and how to retouch, it’s important to understand how we process visual information. There’s no denying that our visual system is remarkable, but it’s far from perfect. It’s incredibly easy to trick. Our brains don’t always interpret what’s in front of us correctly. Our perception is influenced by a number of different things, so that what we see isn’t always what’s there. So, let’s have some fun and take a look at some optical illusions!

Zöllner illusion

Zollner Illusion

These lines are actually parallel. You can also see a dynamic demonstration of this illusion.

Pinna’s Illusory Intertwining Effect

Pinna's Illusory Intertwining Effect

These circles are actually perfectly concentric. It’s easy to throw our visual system off balance.

The Checkershadow Illusion

Checker Shadow Illusion


Squares A and B are the same shade. The proof:


Checker Shadow Illusion Proof

Correct tone and color are the lifeblood of a good photograph. Knowing how people will interpret them is very important.

Poggendorff Illusion

Poggendorff Illusion

We perceive the blue line as connected to the black one, but it’s actually the red line. I’ve moved limbs and strands of hair because of this effect.


Simultaneous Contrast Illusion

The background is a gray gradient. We perceive the smaller rectangle to also be a light to dark gradient, but actually it is one color.

 Ebbinghaus IllusionThe orange dot on the left seems smaller than the one on the right, but they are the same size.

 thaumatropeAnd of course, because I love all old things, I have to conclude this post with the traditional thaumatrope, which is a set of two images on two sides of a piece of paper that you can twirl around on strings to create the illusion of a single image. Classic example: bird in a cage.

So, why is this significant for retouching?

Retouchers need to understand, on at least a surface level, how the brain interprets visual information. People can look at a photograph of something and see all sorts of strange visual phenomena. We need to correct for that in one direction or the other. We can either remove aberrant, confusing visual effects or create illusions to compensate for shortcomings in a photo. One thing I often notice in skin is when pores or light start to create strange, distracting patterns or channels. Have you ever stared at clouds or a stucco wall and started to see pictures? Same effect. We would never notice that in real life. That’s an example of an illusion we need to correct for. Another weird one is limbs that go behind objects and then emerge again at seemingly totally different angles, much like in the Poggendorff illusion. They look like they don’t line up at all! That needs fixing so that the poor person in the photo doesn’t look like they’ve dislocated something. Tonal and color illusions can also completely run amok, especially in mixed lighting, and are a major part of retouching that we always need to be aware of . There are many examples of day to day illusions and they aren’t just limited to photos. We encounter them in life as well. We just don’t notice them as readily because life moves so quickly. There’s no freeze frame without a camera.

Ultimately, optical illusions remind us that experience isn’t always the same as the reality. We are constantly bombarded with all sorts of subtle optical illusions. When looking at a still photograph, we have more time to pick apart those illusions, much like we can pick apart the above illusions when we sit and consider them. Armed with knowledge about how we see, retouchers can bring a photo closer to our day to day experience of a person, place or thing. Sure, sometimes we want the cold, hard, facts about a scene, and sometimes it can be fun to spot all those things we can’t see in the blink of an eye–it can be a game–but art, in the end, is about the human experience, not always cold, hard documentarian facts. Properly armed with the laws of visual science, we can use our understanding of how we see to bring a photograph more in line with how people really visually experience things on a day to day basis.

You may be wondering at this point why we don’t process optical illusions as the norm when we’re looking at things in our day to day lives. We’ll be talking about a meaty subject next week that may explain some of those compensatory mechanisms in How We See Part 2: Gestalt Psychology.

And really, if you’d like to learn more about how we process visual information, I really highly recommend this book. It goes into great detail about our visual systems and psychology. I consider it a must-read for any artist and retouchers in particular: (affiliate link)