"Twins," 16x20, Plein air Maui
If you have ever come in from painting outdoors only to discover that your values are way too dark, way too light, or all right in the middle, try practicing these tips:
1. Use a mid-value mixing palette. If you use a white mixing area, your eyes are more likely to be strained which makes determining values difficult.
2. Key your painting when you first arrive on he scene while your eyes and mind are fresh. Make notes about the key of the painting on a thumbnail sketch of your design.
3. Determine what mass in your scene is a mid-value. Make a note in your sketch. Be sure when you mix color for that area, that the mixture VALUE matches your mid-value mixing palette perfectly. Masses in your scene which are darker than this mid-value mass should be mixed darker than your mixing palette. Lighter passages should be mixed lighter.
4. Work on panels rather than stretched canvas. The light which comes through the back of a stretched canvas will change your perception of value.
5. Keep both your mixing palette and your panel shaded, even if it means having to face away from the scene. There is a tendency to make mixtures too dark when mixing values with either surface in bright sunshine.
6. Once you have been painting for 30 minutes or so, your eyes will begin to "lie" to you. Trust your notes regarding key and mid-value and constantly compare all mixtures to your mid-value mixing palette. Ask yourself how much darker or lighter each mixture should be. Do not second guess your original observations about what is right in the mid-value.
7. When mixing your lightest light, "test" a dot of paint on a white paper towel. Lighter, outdoor mixtures will appear to be almost white. Comparing them to the white of a paper towel will give you a more accurate reading.
8. Most shadows are not as dark as they appear, particularly in the distance. Compare middle and background darks to darks in the foreground. Make notes on your sketch.
9. Use a grayscale card or View Catcher™ and compare masses. Determine how many value steps are between the light, middle, and dark masses. For example, after choosing which mass is in the mid-value, ask your self how many steps darker your darkest darks are; how many steps lighter your lightest lights are. Again, make these notes on your original thumbnail sketch.
10. If staring into the sun, turn away from your painting, close and rest your eyes for a minute or two about every 20-30 minutes.