Scott uses a lakeside scene to key a high, medium and low value composition. He also discusses the relationship between values and planes.
The closer you can keep your values while still being able to distinguish between light and shadow, the better you are as a painter. John F. Carlson Carlson's Guide to Landscape Painting
With the exception of accents, rarely will the extremes of value be found in a painting. Rather, the values will cluster into high, medium and low key groupings where the gap between mid and dark will gradually increase as the key darkens (see value key summary below)
Establish value planes to develop a pleasing composition of line and shape. Then decide the key that will determine the overall lightness / darkness of the planes.
Middle values normally occupy the majority of shape mass in a painting.
Rarely does the darkest dark meet the light. Rather, light infiltrates the juncture of the masses and creates transitional values. The core of a dark usually stays "tucked in" a shadow shape.
As you design, keep track of the pattern your similar valued shapes are making. This will heavily influence the quality of your composition.
As the key darkens, you will find that you can elaborate on dark shapes and increase their size. This gives you the chance to create interesting patterns of dark values.
High Key: 2 / 4 / 6
Mid Key: 2 / 5 / 8
Low Key: 2 / 5 / 9
Find at least one color photo.
Create a ten line composition for the photo and choose values for the major shapes / planes.
Use a photo editing program to create three black and white versions of the color photo with high, medium and low light saturations (as Scott did in the episode).
Compare your initial composition to the black and white photos. Journal your observations paying attention to how color made value patterns easier / harder to discern.
Using the three black and white photos as a reference, develop at least one high key, one medium key and one low key composition.
Optional: Choose one of the designs and develop a color study.
Gouache or oil paints.