Sunday, May 8, 2011

Adjusting Your Key

These two heads were painted during one session. The model didn't move, I did. I just wanted to do some quick studies rather than do a single, more involved painting.

When you take a photograph with a point-and-shoot camera, typically the camera automatically adjusts the exposure based on what it's focused on. (Yes, I'm aware that you can change settings on my camera to do otherwise)  Given a view, if you focus on something in shadow, the camera will make sure that you can see detail in that area by adjusting exposure so that it's light enough. Which results in the lit areas becoming very light, often being washed out. (Because it has to be so much lighter than the shadows).

Conversely, if you focus on something brightly lit, camera adjusts the exposure in such a way that detail is clearly visible and colors very rich in the light area, but the shadows become really dark, sometimes obscuring everything.

Although our eyes are much much more sensitive than the camera and can see a lot more subtler shifts in color and value, they essentially do the same thing. If we're painting the brightly-lit model's head from the lit side, the shadows look pretty dark. On the other hand, if we move the easel so that we are looking into the shadow side, the lights look almost washed out. The lighting didn't change. Our eyes just adjusted.

It helps to be aware that our eyes do this, so that when we're painting, we can use this phenomenon to help organize our structure. In practical terms, here's what I do. If the focal point (or center of interest, if you like) is in light, or if I'm looking at the model from the lit side, I "key down" so that the general value range of the light side falls toward mid range, where colors can be more saturated and richer. Shadow side will necessarily become darker, and I try keep the shadow side very simple. Just a couple of values to define the planes.

If, on the other hand, my center of interest is in shadow, or I'm looking at the model from the shadow side, I "key up". I paint the shadow side near the middle value range, so that I can show more color and definition. If you paint the shadows really dark, you really don't see much color there because you're saying that there's not much reflected or ambient light to illuminate that area. You can't see much of anything in the dark. So if you "key up" the shadow side, what happens to the light side? it becomes lighter still, and become simplified in the higher value range. Almost washed out, depending on how strong the light is and how high you go up in key. Back lit situations are often treated this way.

So the next time you're painting a directly lit head (or figure or teapot or whatever), don't get stuck thinking there's one correct value for that shadow side. Instead, try starting the thinking process by defining in which side –light or shadow–your focal point will reside, and key up or down accordingly, simplifying the other side.


  1. Yep, my teacher at the academy calles it "binding the values" (excuse my poor translation from dutch). Suppose the model would have a black tattoo on the lit part of his face we would paint it in a value closer to it's surroundings than it's actual value, in order to maintain unity.
    Personally, I have a natural tendency to want to use the original value though, but since the overal result is much better when values are adjusted towards more unity, I try to use this approach as often as I can. I guess for some people it's harder to do than for others. I must admit though that it becomes more natural with practice. Maybe there's hope for this sucker after all LOL

  2. It seems most of these decisions we are normally making subconsciously. At least myself. However, I see the value of being aware, and increasing our power to play with our paintings. Love your brushwork on these people.

  3. Great, clarifying lesson! So for landscapes do you tend to focus on the light area, because then the dark shadows can lend drama? I suppose for night scenes the latter is the standard.

  4. Thank you so much Terry for the wonderful tip. It sure is going to be very helpful.

  5. Thanks everyone for your comments - Nice to know this stuff resonates.

    Judy, landscapes can go either way, too. It's all a matter of what the artist is intending to communicate. Most night scenes, whether lit by moonlight or artificial light, (including light from street lights and campfires) tends to have focus/color in the light, yes.