A quick way to make any scene appear more realistic in Photoshop is to add shadows. In fact, there are three major types of shadows that I consistently use in my artwork. They are what I refer to as the Base, Ambient, and Direct Shadows. Each shadow has its purpose and each shadow (when combined with the others) helps to add realism to any scene.
I plan on making this a three-part article in which I will examine a different shadow in each post. This article will focus on the direct shadow. Now, since direct shadows are directly linked to lighting, it can become easy to get off topic very quickly. This article will focus more on the shadows and leave lighting for another time.
The direct shadow (or cast shadow), as the name implies, refers to the shadow that is cast by a direct light source. The direct shadow can do several things to improve your scene—It can help to identify a light source and its direction, it can provide contrast in a scene, and it can help to establish a ground plane.
Since the use of a direct shadow instantly implies a light source, it is good practice to make sure that the direct shadow falls on the opposite side of a light source. Since our eyes are so accustom to seeing shadows and lighting every day, when a shadow doesn’t match the direction of a light source, our brains will automatically recognize that something is wrong with the scene. In the image below, the shadow of the object on the left is correct. The shadow of the object on the right is being cast in the wrong direction.
Properties Of A Direct Shadow
If you examine the properties of a direct shadow, you may notice a few things that occur as the shadow gets farther away from the base. The first is that the shadow appears to fade. This can be caused by the size of your light source or by additional lights filling in the shadows. The second thing that can happen is that the shadow appears to become blurrier as it gets farther away from the base. This is is generally influenced by how hard or soft the lights is or by how long the shadow is.
Another property is that the shadow may appear to taper. Technically, a direct shadow will taper out the farther away from the object it gets. However, this can be dependent on the light source. If the light source is near an object (such as a lamp) then the tapering effect is visible. If the light source is far away (such as the sun) then the tapering effect can be so minimal that it is often not necessary to replicate.
With that said, there are times when a shadow may appear to taper inward. This is just an illusion caused by two light sources.
Now that you know more about direct shadows, I encourage you take a look around your environment for them. Take time to examine how they are cast onto a surface and what type of light is making that shadow (is it the sun, a tube light, a lamp, etc.). As you become more familiar with how shadows work, you’ll find them easier to replicate in Photoshop.