POV: Light and matter

Behaviour of light and matter should be on the top of your list as a subject to know about, specially if you aim to create realistic appearances. Light and shadows, values, are often referred to be the most important thing to focus on when painting or drawing, but why?

Well, since the day you opened your eyes, you have been programming your brains to identify objects from your vision. Objects appear to us in three dimension and we can recognise their forms depending on how they are related to the light source. This creates shadows and shades which we refer to as values. And they appear in a very spesific way, we are really good when it comes to recognising them, and we can tell if somethings off. When working with drawing, we generally compare the values to each other either thru brightness or darkness, but there is much more to it if we dig deeper.

So let´s dig. If you read my POV about human sensory system, you will find out that values don´t appear to us in such a simple manner, but we experience them thru their intensities related to one another. Let´s take a look what this actually means.

In the next image, we can see a sphere, and we can clearly identify lighter reflected light in shadow side of the sphere when the background is dark. However, if we change the background to light, we are not able to see that reflected light anymore. It is still there with the excact same values but we can´t see it.

Ernst Weber stated that Human senses cannot respond to all levels of intensities simultaneously. So when the background intensity increased, that reflected light would have to increase aswell for us to be able to see it. This effect with simultaneous contrast creates optical illusions that change the appearance for us, in other words, our whole visual experience when we open our eyes is kind of illusion already. All the values we see, appear abit different compared to what they are in reality, when they are observed simultaneously. As an example take a look at another image.

This is known as Mach band, we can see darker shade appear left side of the borders between stripes of different values and lighter area on the right side of the borders.

So what does this mean from the point of drawing or painting? We can´t trust our eyes to measure correctly. If we draw a realistic image and just copy and replicate a photo, this will not become an issue, but once we try to change, leave something out or add different things from our imagination into the work, things will turn much more complicated. Since what you add, change or remove, will have an effect on everything in your drawing. If we can´t trust our eyes in the process, what can we trust ?

Well, it´s a good thing that light interacts in a spesific and predictable ways with matter. If you haven´t looked my article about it, I suggest to do so.

Since everything happens in a spesific manner in our observable universe, we can take advantage of it in visual art. Let´s take a look at two ways to simplify your creative process.

As an example, presenting a sphere in an environment with a light source, we can see a clear separation of shadow and light areas. We see shades in the lighted area, those shades appear since the material has the ability to absorb/remove light. In drawing we refer to them as halftones. But our shadow is equally dark.

If we bring additional material into the surrounding that is able to reflect light, it will illuminate the shadow side of the sphere as the sphere reflects that light as well.

What happens is that shadow is being weakened by light. We can apply this by recreating these conditions of appearance simply by creating the shadow with liquid charcoal, then start adding light on top of it with compressed gray charcoal or white chalk. On the side of the light we can add shades by applying charcoal on top of white paper, much like in a traditional way of drawing. Following the same steps that happen naturally in our environment, until you are satisfied with the appearance. We don´t need to measure and compare everything to the excact precision, as mentioned at the beginning of this blog, we know when things look right and when they make sense.

So just go with the flow and trust yourself, you might be surprised what you can accomplish with such a simple approach. And like always, remember to have fun with it.

Sincerely

Mikko