This is a little demo I did for my plein air students this morning. It was an overcast day with skies that looked like they could open up any minute, so I knew we had a limited amount of time to get our paintings done. I always begin with an underpainting–whether working indoors or out–I feel it is the structure that holds everything together. Get your drawing, composition and values right early on, and the rest is easy. This is particularly true with plein air, when you are dealing with things such as changing light and changing weather conditions. You have to get the structure in fast and accurately, otherwise you will constantly be trying to “keep up” with the changing environment.
Artists who are new to plein air sometimes believe that you have to keep changing your painting as the light and atmosphere changes. That is not the case–the key is to capture the light at a given moment by blocking in the values early on, you don’t move the shadows on your painting because the light has moved–you leave them where you blocked them in and use the values as your key to tell you how dark or how light they should be based on what they looked like when you blocked in the underpainting. The actual surroundings tell you what color the elements in your painting are, but the underpainting is why tells you how dark or how light they are. Values are what give paintings depth, dimension and atmosphere–they have to be correct otherwise your painting will look flat. A painting with correct values accurately places the relationships of the darkest darks through the middle values all the way down to the brightest highlights. If you have this worked out in the beginning, you can relax and take your time with the rest of the painting. I’ve often finished pieces off site with no reference other than my initial block in. It’s relatively easy if you have a good drawing, a good composition and accurately mapped in values!
Below is the finished painting. I did this in about 45 minutes, maybe a little less. The underpainting itself took about 15 minutes. If you work quickly and block in large areas, focusing on big shapes and ignoring detail, you can grab the elements that matter early on and imply details later in the final stages of your painting. Working this way produces a more cohesive result, and a fresher, more spontaneous look–and that is what plein air painting is all about!