Learning to see light and shadow

In this lesson, I will tell you how to properly use the light so that your work looks as realistic as possible, because light is what creates the atmosphere. We can imagine an object as a simpler form, and then – a matter of technology. The truth is that if there was no light, we would simply not see anything.

In the first lesson of this series, I will tell you how to properly see light, shadow, reflection. We must learn understand how it works.

As I can see?

Have you ever asked yourself this question as an artist? If not, then this is your big mistake. After all, everything that you draw is only a representation of what and how you see, as well as the laws of physics – it is only an idea of ​​how it actually happens. I will even say more – the fact that we draw this is not a real image, it is just an interpretation of a picture that is constructed from information obtained from the eyes. That is, the world that we see is only an interpretation of reality, one of many, and not necessarily the most truthful or ideal of them, is only optimal for the survival of our species.

Why am I talking about this in the drawing class? Drawing itself is the art of darkening, highlighting and coloring certain parts of paper (or screen) to create a realistic image. In other words, the artist tries to convey the image created in our imagination (which actually makes it easy for our perception, because we all perceive in textures – we are looking for familiar forms in abstract drawings).

If the picture is similar to what we imagine, we consider it realistic. It may look realistic despite the lack of familiar shapes and lines — all we need is a few strokes of paint, light and shadow, to make it realistic in our perception. Here is a good example of this effect:

To create a convincing drawing – that is, similar to what our imagination has created, we need to understand how the brain does it. In the process of reading this article, most of the material will seem quite obvious to you, but you will be surprised at how close science can be to drawing. We perceive optics as part of physics, and drawing as part of metaphysical art, but this is a gross mistake — art is nothing but a reflection of the reality seen by our eyes. So, in order to imitate reality, first of all we need to figure out what our imagination considers realistic.

So what is a vision?

Let’s go back to the basics of optics. A beam of light hits the subject and reflects on the retina of the eye. Then the signal is processed by the brain and, in fact, an image is formed. Well known fact, right? But do you understand all the consequences of this process?

So, here we remember the most important rule of drawing: light is the only thing that we can see. Not an object, not a color, not a projection, not a form. We see only the light rays reflected from the surface, refracted depending on its features and features of our eyes. The final picture in our head is a collection of rays falling on the retina of the eye. The image can vary depending on the characteristics of each beam – each of them falls from different points, at a different angle, and each of them could be refracted several times before touching our eye.

This is exactly what we do during drawing, we imitate rays that fall on different surfaces (color, texture, luster), the distance between them (the amount of diffuse color, contrast, edges, perspectives), and, of course, we don’t draw things that for our eyes do not reflect or emit anything. If you “add light” after completing a drawing, you are doing something completely wrong, because the main thing in your drawing is light.

What is a shadow?

In simple words, a shadow is an area where direct light rays do not fall. When you are in the shade, you cannot see the source of the light. Obviously right?

The length of the shadow can be easily calculated by drawing the rays.

However, drawing shadows can be quite difficult. Let’s take a look at this situation: we have an object and a source of light. Intuitively, we draw the shadow as follows:

But wait, because this shadow is created by only one point on the light source! And what if we take another point?

As you can see, only a point light creates a clear, easily visible shadow. When the light source is larger, or, in other words, the light is more diffused, the shadow acquires fuzzy, gradient edges.

The phenomenon that I have just explained is also the cause of supposedly several shadows from one light source. This kind of shadow is more natural, so photos taken with flash look so harsh and unnatural.

Well, but it was only a hypothetical example, it is worth analyzing this process in practice. This is a photo of my pencil box taken on a sunny day. See a strange double shadow? Let’s take a closer look.

Roughly speaking, the light comes from the lower left corner. The problem is that this is not a point source of light, and we do not get a good clear shadow, which is easiest to draw. And here even drawing such rays does not help at all!

Let’s try something else. According to what I said above, diffused light is created from a variety of point sources, and it will be much clearer if we draw them in a similar way:

To explain more clearly, let’s close some rays. Do you see? If it were not for these scattered rays, we would get quite a clear, normal shadow:

There is no sight without light

But, wait, if the shadow is a section untouched by the light, then how do we see objects in the shadow? How do we see everything around on a cloudy day when everything is in the shadow of clouds? This is the result of diffused light. We will talk more about the diffused light in this lesson.

Drawing lessons usually describe direct light and light reflected as completely different things. They can talk about the existence of direct light, illuminating objects, and the possibility of the appearance of reflected light, adding a little light to the shadow area. You can see diagrams like the one below:

In fact, this is not entirely true. Basically, all we see is reflected light. If we see something, by and large it is because the light is reflected from this something. Direct light we can see only if we look, in fact, straight on the light source. So, the diagram should look like this:

But to make it even more accurate, it is worth making a few definitions. The light beam incident on the surface may behave differently depending on the surface itself.

  1. When the beam is reflected by the surface completely at the same angle, it is called mirror image.
  2. If a part of the light penetrates the surface, this part can be reflected by its microstructures, creating a disturbed angle and resulting in a fuzzy image. It is called diffuse reflection.
  3. Some light may be swallowed up subject matter.
  4. If the absorbed beam can go through, this is called passing light.

So let’s just focus on diffuse and mirror types of reflection, as for drawing they are very important.

If the surface is polished, and has the correct, light-blocking microstructure, then the beam is reflected from it at the same angle as it falls. This creates a mirror effect – this happens not only with direct rays of light directly from the source, but also with rays reflected from any surface. An almost perfect surface for such a reflection is, of course, a mirror, but some other materials are also quite suitable for this, for example, metals or water.

The specular reflection creates an ideal picture from the rays reflected from the object at the correct angle, while with diffuse reflection everything is much more interesting. It illuminates the object in a softer way. In other words, it allows us to see the object without harming your eyes – try to make out the sun in the mirror (I’m joking, never do that).

Materials may have different factors that affect reflection. Most of them absorb most of the light, reflecting only a small part of it. As you know, glossy surfaces are more prone to mirror reflection than matte ones. If we take another look at the previous illustration, we can draw a more correct diagram.

Looking at this diagram, you might think that there is only one point on the surface, reflecting the rays of a mirror. This is not entirely true. Light is reflected in the mirror over the entire surface, just at one point it is reflected exactly in your eyes.

You can conduct a simple experiment. Create a light source (for example, a telephone or a lamp) and position it so that it is mirrored from any surface. It is not necessary that the reflection be perfect, it is enough that you can see it. Now take a step back, continuing to look at the reflection. Can you see how it moves? The closer you are to a light source, the sharper the angle of reflection. To see reflections directly under the light source is impossible only if you are not this source.

How does this relate to drawing? That’s what it is the second rule – the position of the observer affects the shadow. The light source may be static, the object may be static, but each observer sees it in his own way. This is obvious if we think of perspective, but we seldom think of light in this way. Answer very honestly – have you ever thought about the observer when you were working on the lighting of your drawing?

Have you ever wondered why we draw a white grid on glossy objects? Now you can answer this question for yourself, now you know how it works.

The higher the brightness, the better we see.

We are not talking about color yet – while for us the rays can be lighter or darker. 0% brightness = 0% we see. This does not mean that the object is black – we do not know what it is. 100% brightness – and we get 100% of the information about the object. Some objects reflect most of the rays and we get a lot of information about them, and some absorb some of the rays and reflect less, we get less information – such objects seem dark to us. And how do objects look without light? The answer: no way.

This interpretation will help us understand what contrast is. The contrast is determined by the difference between the points – the greater the distance between them in the scale of brightness or color, the greater the contrast.

Gray contrast

Look at the illustration below. The observer is at a distance x from object A and at a distance y from object B. As you can see, x = 3y. The greater the distance to the object, the more information about the object is lost, so the closer the object is, the more it is for us..

Next is another situation. The difference between x and y is less – x = 1.3 y. Therefore, the loss of information is about the same and the contrast is less.

So the observer will see these objects.

But wait, why are nearby objects darker and distant ones lighter? More brightness, more information, right? And we just found out that as the distance increases, information is lost.

We have to explain this loss. Why does the light of distant stars come to us almost unchanged, and the high-rise building a few miles from us, we already see worse? It’s all about the atmosphere. You also see a thin layer of air when you look at something, and this air is full of particles. As the rays reach your eyes, they pass through many particles and lose some of the information. At the same time, these very particles themselves can reflect the rays into your eyes – so we see the sky blue. In the end, you get only the remnants of the original information, and yes even mixed with reflections of particles – very poor-quality information.

Let’s return to the illustration. If we draw loss of information with a gradient, we will clearly demonstrate to ourselves why nearby objects look darker. Also, it will explain to us why the contrast between nearby objects is greater than the contrast between distant objects. Now it’s obvious to us why contrast increases with distance.

Our brain perceives depth and volume by comparing the information received from each eye. Therefore, distant objects look flat and near ones are voluminous.

The visibility of the edges in the picture depends on the distance of the object. If your drawing looks flat and you circle the edges of the objects to highlight them – this is wrong. Lines should appear by themselves as borders between contrasting colors, so they are based on contrast.

If you use the same parameters for different objects, they will look like one.

Art of shading

After reading the theoretical part, I think you have learned quite well what happens when we draw. Now let’s talk about practice.

Volume illusion

The greatest difficulty in drawing is to create a three-dimensional effect on a simple sheet of paper. However, this is not much different from drawing in 3D. This problem can be avoided for a long time, focusing only on the so-called cartoon style, but in order to progress, the artist must face the main enemy – the prospect.
So what does the perspective have to do with toning? Surely more than you think. Perspective helps to depict three-dimensional objects in 2D dimension so that at the same time they do not lose their volume. And, since the objects are three-dimensional, the light falls on them at different angles, creating highlights and shadows.
Let’s do a little experiment: try to shadow
the object below using this light source.

It turns out like this:

Looks flat, huh?

Now let’s try this:

It turns out something like this:

It is quite another matter! Our object looks three-dimensional thanks to those simple shadows that we added. And how does this happen? The first object has one visible wall, that is, for the observer it is only a flat wall, nothing more. Another object has three walls, while a two-dimensional object cannot have three of them in principle. For us, the sketch looks three-dimensional, and it’s easy to imagine the parts that the light touches or does not touch.

Next time, when preparing the sketch, do not use lines alone. We do not need lines, we need three-dimensional forms! And if you give the forms the correct definition, then not only your object will look three-dimensional, but also shading will seem surprisingly easy.

When the basic flat shading is complete, you can finish the drawing, but do not add any details before. Basic shading determines the lighting and allows you to keep everything in line.

Terminology

Let’s take a look at the correct terminology that we will use when talking about light and shade.

Full light – place right below the light source

Glare – the place where the mirror reflection falls on the retina of our eyes. This is the brightest part of the form.

Half light – dimming full light towards terminator

Limit – virtual line between light and shadow. It can be clear or soft and blurry.

Shadow area – a place located opposite the light source, and therefore not illuminated by it.

Reflected light – diffuse reflection falling on the dead zone. Never brighter than full light.

Shadow – the place where the object blocks light rays

And although it looks quite obvious, the main lesson you need to learn from this is – the stronger the light, the more pronounced the limit. Therefore, a clear limit is in some way an indicator of an artificial light source.

Three-point lighting

If you understand what a vision is, the photo no longer looks so different from drawing. Photographers know that it is the light that creates the image, and uses it to show something definite. Often in our time it is said that photos are too “photo-framed”, in fact, photographers rarely shoot something for what it is. They know how light works, and use this knowledge to create a more attractive image — this is why you are unlikely to become a professional photographer simply by purchasing an expensive camera.

You can use two different approaches, selecting the light for your design — imitate natural, depicting light as it is, or “play” with it, creating light that shows the object as most attractive.

The first approach will help you create a realistic image, while the second approach will help improve reality. It’s like a warrior in a worn armor with a mace in her hands against a beautiful girl elf in shining clothes and with a magic wand.

It is easy to say that it is more real, but what is really more fascinating and beautiful? Your decision, but always remember that you need to take it before drawing, and not in time, or change because something went wrong.

To clarify – we are talking about the light, and not about the subject of the picture. You can draw a unicorn or a dragon in natural light, and you can use a light to ennoble a weary warrior. Playing with light means positioning its sources so as to best show the relief of the muscles or the brilliance of the weapon. In nature, this is rarely the case, and we perceive all the objects of the scene as a whole.
Therefore, I advise the method of natural light for landscapes, and the improving method for characters, but by mixing the two approaches you can create even the best effect.

We can only learn about realistic shading directly from nature. Therefore, do not take as a basis the drawings of others or even photographs – they can deceive you in such a way that you will not notice. Just look around, not forgetting that everything that we see is light. Arrange the specular and diffuse reflections, trace the shadows, and create your own rules. However, do not forget that in a photo or drawing people tend to pay more attention to details than to the situation around them. Pictures and photographs are easier to “soak up,” so they convey only the author’s feelings, on which one can focus. The consequence is that the work will be compared with other images, and not with reality.

If you still decide to use a different approach, I will show you a little trick. Photographers call this three-point lighting. You can also use the two-point method for the most natural effect.

Let’s put the light source in front of the bear. Use it to add light and shade, and blend them. This light source is key.

To get the bear out of the darkness, put it on some surface. Light will fall on the surface and the bear will cast a shadow on it. Since the rays falling on the surface will diffuse, they will be reflected on the bear. Therefore, a black line appears between the surface and the bear – and it will always appear under the object only if the object is not united with the surface.

Put the bear in the corner. As the rays of light fall on the wall, many diffuse reflections appear everywhere. Thus, even the darkest areas are slightly lit and the contrast is balanced.

What if we remove the walls and fill the space with a dense atmosphere that will be visible? The light will be scattered and we will again get a lot of diffuse reflections. Soft light and diffuse reflections on the left and right of the key light source are called filling light – it will illuminate dark areas and thereby smooth them. If you stop here, you will receive the illumination that is usually obtained in nature, where the sun is the key source of light, and diffuse reflections from the atmosphere create fill light.

But we can add a third kind of light – framing light. This is a rear light, positioned so that the object itself blocks out most of it. We see only the part that illuminates the edges of the object from behind – so this light separates the object from the background.

Framing light does not have to create this stroke.

Another tip: even if you don’t draw the background, draw the object as if the background is there. Since you are drawing in digital mode, you can always substitute the background temporarily to calculate all the nuances of the lighting, and then remove it.

Conclusion

Light forms everything that we see. Rays of light fall on the retina of the eye, carrying with them information about the environment, about objects. If you want to draw realistic, forget about the lines and shapes – all this should form the lighting. Do not separate science and art – without optics, we could not see, let alone draw. Now for you it may look like a bunch of theory – but look around, this theory is everywhere! Use it!

This lesson is just the beginning of the series. Wait for the second lesson, where we will talk about everything related to color.

Enjoy!

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