Drawing Shadows

If you are referring to a still life lit through a window or an outdoor scene (plein-air) lit

by sunlight, observe very well the light source, take notes and take photos because

the light of the sun changes relatively quickly. If you are imagining and inventing a

scene it is more important than ever to understand how light and shade behave.

It also important to have a sound understanding of the design elements and principles,

especially value and contrast. Thus is the advantage that drawing and painting can have over photography. The ability to creatively tweak and rearrange theses things to suit a composition.

Moving on:

Compare the sketch above of a shadow caused by a light source directly behind 

 to the left image where the light source is behind and to the side a little.

See how the shadow shape changes.

Now compare when the light source is directly above. So you must deduce from

this that it is also important to think about what time of day you are portraying

because of course this will effect the position of the light source and the resulting

shapes that occur in the shadows.

Imagine the object is a tree, the shadows will only be long if the light source is

lower in the sky.

If you want realistic shadows, follow these steps to ensure that the perspective of the shadow is believable.

This is a single point perspective

Step 1: Draw your object (If you have not studied Linear Perspective yet,

this subject will help you understand vanishing points)

Step 2: Determine the position of your light source

Step 3: Locate the shadow's vanishing point. (The shadow vanishing point

will be vertically beneath with the light source)

Step 4: Draw a line from the light source through each of the top outer corner

of your object (be sure to extend the line well pass the corners)

Step 5: Draw a line from the shadow vanishing point to each of the respective

 bottom outer corner of the object (be sure to extend the line pass the corners)

Step 6: The points where the top and bottom line intersect will be a corner of your

shadow. Connect the points together to form the shadow shape and shade it in.

Try this procedure with a few different shapes.

To the right is a 2 point perspective drawing showing the horizon, 2 vanishing points and a cube that results, the next image showing the rays of light forming the resulting shadow (showing the vanishing point from the light source which starts below at the horizon .)

NB. These simple sketches are not showing a lot of important information about the shadows . For example;

*  A shadow is usually darkest nearer to the object, gradually getting lighter the further away it stretches and the edges getting softer, less defined.

* The shadow is made up of the umbra (closest to object), the penumbra (middle section) and the antumbra (furtherest away from the object)

* The shape of a shadow can change as it takes the shape of the surface it falls upon

WHEN PAINTING

* Depending on the nature of the object causing the shadow, it's cast shadow is usually warmer closer to the object. 

* Objects nearby can reflect light and colour into a form shadow

*  Some artists add a little of the complimentary colour of the object colour to it's shadow colour

* In a landscape, horizontal objects will reflect the colour of the sky, so some upward facing shadows will often appear cooler than downward facing shadows.