Tone is the degree of light or dark on, or of, any object or space. You can see the tone of anything much better if you half close your eyes and squint at it. As I mentioned before, your eyes see too much. Therefore, to see the amount of tone available, cut down the lights and half close your eyes.
Even then you will, in all probability, see too much tone. Tryout another window view, adding tones this time and see what happens. Light does funny things to color, it affects it in different ways. With shadows, too, the color changes. But if you half close your eyes, when drawing particularly, these changes are not so disturbing. You can grasp the shapes better.
Light behaves in diverse ways out of doors, but is quite different indoors. Out of doors the light constantly changes and is dispersed over a wide area. Inside, the changes are not so noticeable because they come from one source, namely, the window. Therefore it is perhaps easier to understand the way that daylight acts from inside.
There are three things to remember about light falling on a solid object. One, that the part nearest to light is getting the full amount. Two, as the object turns from the light it becomes darker. Three, as the object continues turning it picks up reflected light (see illustration).
Practice drawing with an eye to these changes. It will help you to understand the solidity of objects and the space around them. And as you have already practiced gradating tone you will be able to apply that knowledge to the gradations of natural light.
Again, the half-closing of the eyes will enable you to evaluate the changes of light and dark more easily. Also your use of the black media with white chalk will help you register the changes with more conviction.
Until you have well versed yourself in the understanding of tone through using the black media, don’t move on to pen and ink or wash, just yet. It demands a different mark to make a tone with pen and ink. The gradations are harder to pin down. Crosshatching and scribble are the best means to employ for shading with pen and ink. The use of washes will be discussed in the chapter on watercolor.
You will find that if you trust your eyes, and your pencil in checking the varying angles you see, you will have no difficulty at all in achieving distance and space.
If it should bother you at all, ignore it. Perhaps your eyes are seeing better than you think they are.
Summing up, then, planes and perspectives are means of creating space in your picture, through light and line. There is also the fact that in diffused or unequal light, the edges of an object disappear into the surrounding background. It is well to note these subtle changes, because they all help to create the effect of space round an object.