Thursday, March 27, 2008

Springfield Pastel Workshop - Wednesday

Although rain had been predicted for Wednesday, the day turned glorious and full of spring sunshine. It was still a little cool, but with a jacket, some of us found it warm enough to paint outdoors. Others stayed inside, working either from photos or from life, observing buildings and trees through the grand new windows that had been installed just the week before.

As an outdoor demonstration, I showed how I paint my 30-minute, 5x7 pastel sketches. As I've mentioned elsewhere, these sketches are "risk-free." They require few materials and little time, but the payback can be big in terms of honing your skills of observation. Here's my sketch of a historic brick building across the street in the early morning sun.

Value was one of our discussion topics. While visiting students at their easels, I walked around the property with a value finder to verify (and even disprove) some theories I'd read about how value works in the landscape. I'll present my full findings in my next book, but for now let me offer one curious observation about value finders: you can't trust them.

For example, here's a paved driveway as seen through a value finder. The red circle indicates the value of the pavement.


Now, here's exactly the same scene. You'll note that the value of the pavement seems to have changed significantly.

Why? Well, neither the light on the pavement nor the pavement's intrinsic value has changed. What has changed, however, is the incidence of light on the value finder itself. The first photo shows the value finder in full sunlight; the second shows it tilted into near-shadow. I found I could get the pavement to read as any value I wanted just by tilting the tool a little more or a little less. In fact, it was almost impossible to avoid tilting the tool and getting erroneous readings.

Tilting the tool changes the angle of light hitting the cardboard, allowing more or less light to illuminate it.

Two properties are at work. As the amount of light hitting the cardboard increases, the value scale becomes brighter, thus making the pavement seem darker. Also, your pupil constricts as it adjusts to the stronger light. (The camera adjusts, too.) This allows less light from the pavement to enter your eye, and again, the pavement seems darker.

The best value finder is your naked eye. You just have to get better at comparing values.

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