We are used to seeing color only as an attribute of an object, and light is a factor that can change this. Tomatoes are red, the grass is green, and the light can only change a little the shade or light the object, right? .. No.
Color does not exist by itself – it is only the effect of the mechanism of our vision. There is no light, there is no color – you do not see the color of objects when it is dark? This does not mean that darkness prevents us from seeing light, it means that light “creates” color. If this is not obvious to you, read on, because the artist needs to know this. I recommend that you first read the first article in the series so that you do not have many questions.
What is color?
Let’s remember the physics. Do not worry, I’ll chew for you all the material as much as possible. Some objects are radioactive, which means that they emit microparticles. Light is like radiation, because each light source emits photons.
The photon flux is formed from waves of different wavelengths.
The flow of photons emitted from a light source somewhere we call a beam.
These are just a few facts. But what happens when you consider the human factor? There are a lot of electromagnetic waves around us, but we can only see waves of a certain frequency. For example, we do not see heat, because the corresponding electromagnetic waves lie outside the visible light range (however, if you heat up the metal to a certain temperature, it becomes red for us). Those electromagnetic waves that we can see, physicists call the visible light, and we – just light.
In our eyes, two types of photoreceptors are functioning – rods and cones. When a beam of light hits them, they send information to the brain.
The rods are very sensitive to light, they are responsible for the vision of movement and form, as well as for night vision. With cones all the more interesting. They divide waves in frequency, so that the brain can process them into red (long waves), green (medium) and blue (short). The color that we see is formed depending on the proportions in which these types of waves are mixed in the stream of light.
But why then in a stream of light can there be waves of different lengths, if they come from the same light source? Most rays fall on an object and are reflected further (for example, on the retina of your eye). Usually the object does not reflect the rays as perfectly as, for example, a mirror. Waves of some frequencies are completely absorbed by objects and they never reach our eyes. As a result, only part of the original waves reaches us. These “remnants” of the beam are interpreted by our brain in color. Different colors result from the fact that different objects absorb and reflect waves of different frequencies.
Perhaps you do not understand how this is all connected with the representation of the concept of color in our business. In the end, we draw only the color, we do not need to simulate physical processes to get it. Soon everything will become clear to you.
Hue, saturation, brightness
And yet, is there something more complicated? We know that there is hue, saturation and brightness, but when it comes to drawing, it is difficult to guess how to control these parameters. Hue it, hmm … color, right? Saturation – the level of brightness of the color … and the brightness, in fact, tells us a dark object or a light one. Everything seems clear enough, right? But this is understandable only when we are talking about finished work; to understand what to do with all this can be very difficult. Anyway, we only need to understand where these values come from!
Shade determination
Hue is the “type” of color. Red, purple, olive, crimson – all these shades. They arise due to the above mechanism – the reflected light waves of different lengths are mixed in different proportions and create the final color. It follows that, the shade, in simple terms, is based on the “color of the object.” An interesting fact – silver, gold and brown shades are not. Silver is a brilliant gray, gold is a brilliant yellow, and brown is dark or unsaturated orange.
No matter how many names we come up with for shades, they are all based on three colors: red, green and blue. The further you are on the light ring from the main color, the closer you are to the original shade. For example, 50% of red + 50% of green will give yellow, but as soon as we change these proportions in the direction of any of the primary colors, we will get reddish or greenish hues.
Hue can not be stronger or weaker, therefore, on the color ring, we define it not in percentage, but in degree measure.
Saturation determination
Hue does not mean color (at least formally). The circles drawn below have exactly the same shade, the same position on the color ring, even their brightness is the same. So why do we perceive their colors as different?
By general definition, how much white is contained in a color depends on saturation.
But wait, isn’t it about brightness? You want to make the color brighter and add more white … but this will make the dark areas more saturated. Confused right? Therefore, we need a more detailed explanation.
Saturation is the predominance of color. Three examples below have the same shade and brightness, the only thing that changes is the proportions. We do not add white, we only reduce the difference between the components of the color so that none of them stand out.
As you might have guessed, where there is no difference between the color components, there is no saturation, and we get white (so far without taking brightness into account).
Brightness detection
Brightness is the maximum value of the luminous flux that our eye can perceive. There is no “bluer” color than 100% blue, nothing is brighter than 100% white.
“Stripes” of colors can not matter more than the maximum.
That is, black is obtained when we do not receive information about the object at all.
Interesting fact: when it is dark, the cones almost do not receive information, so we practically can not distinguish colors in the dark. But the sticks, more sensitive to light, are activated. Since they are more sensitive to blue and green shades, in the dark red shades look much darker for us. This effect is named after Jan Purkinje.
In addition to absolute brightness, each light has its own brightness (note: a translator: there are separate terms for this in English, unfortunately, not in Russian). That is, the brightness in this value – how much color is close to white.
If we discolor 100% bright shade to shade of gray, its brightness will not remain one hundred percent. When discolored, blue turns into very dark gray, and green turns very light. It depends on the sensitivity of the cones, and that is why we perceive yellow (red + bright green) as the brightest light. The brightness of the color is important when we consider its discolored counterpart.
HSB model
This may seem confusing to you. In reality, we do not represent color as such a complex structure with such a set of parameters. Hue, saturation and brightness are combined into one convenient color model. Look at the diagram below – is its pattern obvious to you? So why don’t you use it?
If you draw in a figure, it will be more clear to you. So, HSB (English Hue, Saturation, Brightness – tone, saturation, brightness) – color model. How does she work?
If you understand what these parameters mean, it will not be difficult for you to make this model. Ring tone (or strip) and the triangle / square of brightness and saturation – model SB.
Model SB can be divided into areas. If you have visually selected the desired color, you do not need to know the saturation and brightness values.
Of course, the square model is more intuitive and understandable, but I prefer to work with a triangle. The triangle model allows you to combine saturation and brightness. I use this Len White plugin:
http://nerdchallenge.com/lenwhite/LenWhite.com/LenWhite.com/Entries/2012/9/16_PW_CS6.html
CMY and RGB models
Recall for a moment about these artists. They do not have a color ring on hand with a convenient slider. How, in this case, to change the brightness, hue, saturation of the pigment?
First of all, let’s think about what is the difference between real drawing and drawing on a computer? In both cases, color is used, right? The problem is that in digital drawing we use the best and brightest colors that are immediately apparent, whereas in traditional drawing we are limited by the light reflected from the pigment. This is how to use an intermediary between what is drawn and what we actually see. You can discuss for a long time on the topic, what kind of drawing is closer to art; but, no doubt, drawing on a computer is perceived better by the mechanism of our vision.
So, for the traditional drawing we need paint. They themselves do not emit color, instead they absorb light incident on them, and reflect light waves of various lengths, combined, in fact, with their name. For example, red paint absorbs blue and green, reflecting only red light.
The problem is that we cannot create the perfect color only by reflecting light. CMY spectrum is a kind of compromise: cyan does not reflect red, magenta does not reflect green, and yellow does not reflect blue. That is, if we want to stimulate “blue” cones, we need to mix cyan and magenta – these colors will reflect as little as possible of red and green. In addition, black is also added to the CMY gamma, since the components of this spectrum are not perfect and mixing them in equal proportions will not give black.
In the RGB model (additive channel) we add shades to the original; in CMY (subtractive channel) the opposite is true: the less shade we add, the brighter the final color will be.
Four rules for mixing colors
Rule # 1. Mixing shades
If you mix two shades, we will get a shade somewhere in between, according to proportions. Applicable in both additive and subtractive blending.
Rule # 2. Mixing Extra Hues
You may have heard of additional colors – these are shades lying across from each other on a color ring. The contrast between them (when both shades have the same brightness) is as strong as between white and black. However, if they are mixed, they sort of neutralize each other.
Mixing additional shades gives a neutral color (gray or grayish). An additive blending of 100% bright additional shades will give white, subtractive – black.
In the subtractive blending method, adding a small amount of extra tint will certainly reduce brightness.
Rule # 3. Saturation mixing
In both methods, the proportions are equalized when mixed, and as a result, the saturation decreases.
Rule # 4. Mixing brightness
With additive blending, we get a brighter color, with subtractive – the color is darker than the brightest of the two colors.
Colour temperature
The tradition to divide colors into warm and cold has long been established. We know that warm colors are active and friendly, and cold colors, on the contrary. You can write a lot of books about the psychology of colors, but the fact is that colors are divided into cold and warm spectral. What color is warmer, red or yellow, can you tell? Purple color – cold or warm? Where is this boundary of separation?
Look at the diagram. It turns out that theoretically all red shades are warm. However, there are shades of red that look cooler. It’s all about the contrast. Color can not be warm or cold, only warmer or colder. Ring shades are easier to divide into the cold and warm half. Cut out the red color from the palette, and there will not be cold and warm. It will be only red.
So how do we create a warmer or colder shade? All the tones on the wheel – neighbors. Each shade has neighbors warmer on either side, colder on the other. If we need a shade colder than the original, just move around the ring in the appropriate direction.
Basic Shading Rules
So, we come to the most important thing. Give me a few minutes and you will see for yourself that this huge introduction was necessary. If you remember only the rules and do not know where they come from, your knowledge will be limited, but if you really understand how it works, then there are no obstacles for you!
Main color
The main color, not highlighted by any light source, called the primary. Hmm, we know that this does not happen … It is better to say that the main color is a color that is not strongly influenced by either light or shadow. That is, the cherry is red, even if on one side the sun illuminates it to orange, and on the other, the dark side, it is maroon. The cherry itself is still red.
What should be the saturation and brightness parameters of the main color? Brightness is determined relative to the whole picture. To see true brightness, place your object on a sheet of white paper. Both the object and paper are illuminated with the same light source, and the object cannot be brighter than paper.
Everything is explained simply – a sheet of white paper reflects 100% of the light. If the object is brighter than paper, then it must reflect more than one hundred percent of the light, and this is impossible. It’s all about the contrast.
And what about saturation? If the brightness depends on the intensity of light, then the saturation depends on the proportions of the color. And the proportions of color remain static if the intensity changes (there is one exception, which we will talk about later). It’s like adding water with every spoonful of sugar – tea will not become sweeter.
Direct light source
Let’s recall one scheme from the previous article:
Let’s start with a very simple picture. The grass is green, the ball is red, the sky … whatever. If the background is far from the object, it does not affect it at all. Now, without a direct light source, the picture looks flat. We call colors in this case “flat”.
When a direct light source is present, it fills the entire space. Its intensity — brightness — is maximum at the points at which light falls directly, and minimum at points at which light almost does not fall (shadow areas).
So that the ball does not hang in the air, but lay on the surface, we need to draw a thin shadow between the ball and the surface. We discussed this in the last article. This shadow is the darkest area of the picture.
The problem is that the picture still looks unreal. It is colorful, but it feels like this picture is from a children’s book. Something is wrong. If you carefully read the first article in the series, then you understand that we used only diffuse reflection. Each ray of light falling on the ball is partially absorbed and reflects only the red color. That is, in the area where the light falls, we got 100% red and we cannot change it! This is normal for opaque materials, and in this case, reducing saturation to get bright red is wrong.
Then what is it? The fact is that completely matte materials in nature are very rare. That is, most matte materials also have a little mirror reflection ability. Move a little, looking at any object, and if the shade in some of its areas will change a little, then this object is able to reflect and mirror. If the type of the object does not change at all, then it is completely matte.
Mirror reflection, as we have found out earlier, is a reflection of the light source. A big role is played by the ratio of the ability of an object to reflect diffusely and specularly.
When we reduce the saturation of the bright part of the object (add white, so to speak), we do not increase its brightness – we increase the brilliance.
One way or another, our ball is still not real. Now it looks as if we found somewhere a 3D model. The fact is that we used neutral white – and in nature this can not be. Sunlight, until it reaches our eyes, passes through the layers of the atmosphere. In general, we already talked about this in the first article of the series.
Waves of small and medium lengths are scattered most easily. The more their way through the atmosphere, the more they dissipate, and may not even reach your eyes at all (in any case, not from the original source). Therefore, the “white” beam becomes mostly red and green, and even at the highest point there is a slight lack of blue – the sunlight is warm.
So why is the reflection from a source of warm light neutral white? To avoid this effect of an artificial 3D model, lower the saturation and increase the temperature, adding a warm shine at the same time (no matter whether it is strong or not). As we noted earlier, red is warm and cold, that is, the surface does not necessarily turn orange or yellow.
It is important not to be accustomed to constantly use shine to make your work more attractive. If you feel that you are approaching white, it means that your object is shiny or wet. Keep this in mind when drawing your skin.
Indirect light sources
But what happens to all this blue that dissipates? Of course, it makes the sky blue, but if we see a bright blue, it means that the color falls into our eyes, and not just our eyes. Indirect light touches everything around, and, reflected, it becomes visible to our eyes. It is not as bright as direct sunlight, and yet, it can make the surface a little brighter. Also, if the surface is not completely matte, the color of the surface loses saturation, acquiring a cold hue (since our indirect light source is cold). Remember that direct light is much stronger than indirect light, and they will never mix – the reflection of indirect light cannot cross the limit line.
Smooth and shiny surfaces have the greatest ability to reflect, but dull, like our “earth”, also affect objects.
As we noticed in the previous article, the contrast with distance decreases. But what happens with the hue, saturation and brightness of the object being removed? Everything is a little more complicated here. When the object is removed to the background, the color information it carries mixes with the light reflected from the sky, right? It means that:
• The hue gradually changes the temperature in the direction of the sky hue.
• Brightness gradually increases until it reaches the brightness of the sky.
• Saturation is mixed with noise, so it drops. But if the light source is in the background (and in the foreground is dark), then the saturation will gradually increase as you approach it.
The cleaner the atmosphere, the less often this effect takes place. For example, where there is a lot of dust, smoke, or very humid, even a closely located object will radically change its properties. The well-known feature of many artists (and, by the way, filmmakers) is the creation of deep perspectives even over short distances, for example, drawing one leg of a monster with a deeper, brighter blue. For our brain, this means that the foot is farther away – that is, we have reached depth. Anyway, remember that such a trick “thickens” the atmosphere and does not work outdoors.
Color and color brightness
Proper color filling creates the correct brightness, so to speak, unintentionally. Newbies often start their pictures with the brightness distribution, so that everything goes, so to speak, like clockwork, but, in fact, with the rules we’ve just learned, you should have no more problems with working with color. Indeed, what could be the problem?
• The initial brightness of the primary color sets, so to speak, the brightness for the entire pattern.
• Scattered light and shadows are as rich as the main color
• The more shine – the more color brightness
• Indirect light is never brighter than direct light, which means it cannot be confused with the main light source.
• The base color becomes the limit line, with highlights on one side and shadows on the other, creating the right contrast.
How to check whether it is worth adding more light or shadows? It all depends on the contrast, and then you yourself need to choose which one is better suited to the atmosphere of your drawing. In general, it would be nice if you put an object on three backgrounds: white, black and 50% gray. If your item looks good on all three – everything is going fine. Bleaching your pattern for comparison is also a good idea.
What you need to remember
• Very saturated, bright colors are extremely rare in nature, leave them for flowers, birds, and magic items.
• Place light on the light, and never light on the shadow! If you want to illuminate a dark place, do it gradually.
• If the shading looks too colorful, arrange a short break for your eyes, look at the drawing from afar. There is a great chance that after hours of work your eyes are too focused on him, and in fact the colors are all right. Here the rotation of the picture or an indirect glance at it, for example, through a mirror, can help.
• Leave 100% white for highlights, and black for so-called “gap” shadows. Their excessive use will drastically reduce their strength.
No more guessing!
As soon as you realize that color is just a signal, a type of information, it will become much easier for you to imitate the real world in your drawings. You do not need to memorize thousands of rules as soon as you understand the basics – you can calculate reality with amazing accuracy! Of course, do not accept them as a universal recipe for success – art is art, and sometimes the best effect can be achieved if you break the rules.
Expect the latest article in the series, in which I will show you new pieces, such as multiple and colored light sources, transparency, distribution and light refraction, and tell you about all this fuss about textures.
Author: Monika Zagrobelna
