When the universe was born, it was just hot little particles between ~light~ and energy. (POT)

 

I'm not a rocket scientist or anything, but thanks to light we can perceive our reality visually, so as visual artists we can say that, somehow, everything in our work is light. We don't need to study physics (although it would help a lot) to understand in a very simple way how light works, in fact there are still many mysteries around it, but knowing some properties can make a huge difference in your work :) I hope it helps you a lot !

Direction

First of all, you need to know where your light is coming from. When lighting, it helps me a lot to put a visual reference (that is, a little dot) to correctly locate what I am going to illuminate and what I am going to leave in the shadow (a good narrative process starts from here).

 

Also keep in mind that, although we are in a 2D plane, we are representing a space in three dimensions. The light bends like a blanket on the surface, and thanks to this we can perceive volume.

Intensity

This is quite simple, the more intense a light, the higher the value of what it is illuminating, or in other words, the brighter it will be.

 

Just be careful not to 'burn' your illustrations, just like in photography, try to avoid pure white. Thus, if you want to use it later for some detail or accentuate an area, you can do it.

Position

Going back to 3D space, you can position your light where you want. The further you move away from the light source, the greater the fall, that is, it loses intensity. This is called ~falloff~ and the closer the light is to your target, the more obvious it will be.

Form

Another thing to consider is the shape of your light source, or the obstacles that are between it and your object to light. If your main source is the sun, but it has to pass through an opening before reaching the object, the light will cast the shape of that opening. Or if your light is coming from a projector, this circular shape will still be projected onto the surface (remember to pay special attention to the volume here!)

Color

Finally we have the color of the light, which will always have a relative effect on the material it illuminates, it can darken it, intensify it, change its hue, so always watch! Look for references to be more precise or do your own experiments.

shadows

So far we have only talked about light, but what about its absence? When the light does not reach certain areas, a shadow is projected, either on the object to be illuminated, on some surface blocked by the object or due to the proximity of two surfaces.

 

In the first case, the cast shadow is made up of the ~umbra~ which is the darkest area, closest to the object and the ~penumbra~ where the light begins to penetrate but not enough to eliminate the shadow.

 

In the second case, it is easier if we imagine that our object is composed of different faces, like a 3D model, the faces that look more directly towards the light will light up more, and vice versa, these shadows are what give volume to our object.

 

In the latter case, the closer two or more surfaces are, the less light will reach this area, until it is zero. This applies the same between the object to be illuminated and the surface on which it is located. This is called ~occlusion~

Hard Light - Diffused Light

Now, we are going to go a little deeper into how we perceive light. It is common to hear this division, and it is directly related to the way the shadows are cast.

 

A 'hard' light produces very sharp shadows because all or a large percentage of that light comes from a single, highly concentrated point. On the contrary, a 'diffuse' light has a lower concentration throughout a larger area, which causes the light to come from more points and the shadows that begin to be created in some areas end up being canceled by other points of light. . In short, the transition from light to shadow is much smoother than in hard light, making them look more blurry or out of focus and leaving less room for areas of absolute darkness.

Material

Since we have the characteristics of our light, and we have considered the volume of our object to illuminate, we must also take into account the material that we are lighting.

 

The quality of an object being like a mirror is called ~specular~ (Merriam Webster). The smoother a surface, the better it reflects light and the more irregular it is in more directions the reflected light spreads, until it gives it a matte effect. (Nadia Dibaj has an excellent tutorial here on CST on this topic!)

 

An object can also be classified based on how much light it allows to pass through it. An ~opaque~ object doesn't let light through, a ~translucent~ object lets a fraction through, and a ~transparent~ object transmits almost all of the light, letting you see clearly through it.

By last! We must not forget the color of the material, as we said before, the color of the light will affect the color that we perceive of the material, both in value and in its hue, whether it is colder or warmer. If it is a color without hue such as white, gray or black we will only see the change in its value and it will take on the hue of the light.

Placement Examples

Now that we know a bit more about how light behaves, we can do a simple placement as an example and look at one last light modifier.

 

Suppose we have a very intense light source coming from above (like the sun). We know the shadows are going to be pretty harsh, but at this point we haven't really taken ~medium~ into consideration. I will not go into this topic much since we have enough information for now. We just have to know that our atmosphere changes the way light reaches us, as it scatters it in all directions, so we will have a bit of diffused light apart from direct sunlight. Even so, there are certain contact areas to which almost no light will reach. We add to this the reflected light coming from the highlights in our scene and voila! We will have a simple but effective placement with occlusion, sunlight and its respective reflection and dispersion.

 

As a note, check that more or less on the horizon line of each volume in our object there is a darker line, where neither direct nor reflected sunlight reaches as well as in other areas. This is called a ~terminator~

Here we have a second location that is very classic in photography, only at a slightly lower intensity. We have a main light on the left, a smaller secondary light on the right to remove a section of the shadow from the first light, and a light commonly known as a ~rim light~ from behind to lift the character from the background and better define their silhouette.

 

Now if we change the highlights value a bit we can suggest a more specular material, we just darken more of the volume (since it's reflecting the dark environment) and make the glow more defined, as if the surface is reflecting the source of the light. light more than being illuminated.

And that's it! Just remember that light is very relative, so my greatest recommendation is: observe! We have a wonderful world with infinite possibilities and if you pay a little attention to it, it will teach you more than you can imagine. Observe, experiment, practice and soon you will be able to use light not only as a descriptive element but you will also be able to exploit its enormous narrative potential. I hope that this little tutorial has aroused your curiosity a little bit and that you have learned a lot (:

 

And well, it really never hurts to study a little optics: b