Black Umbrellas

Susan asks: "Do you recommend black umbrellas for plein-air artists?"

No, I really don't. Here's why I don't think a black or silver umbrella is useful. The goal of any sun-modifying system should be to transform direct sunlight into soft (indirect) light. The amount of light on the artwork—and the color of that light—should be as similar as possible to the amount and color of the light on the subject. 

The problem with blocking the light entirely with black or silver material is that the level of illumination will be too low on the work, making the eye have to adjust from one to another. Worse yet, the only light shining on the work is whatever bounces up from the ground. This light is often highly colored, especially if it’s grass, bricks or dirt, making accurate color judgments almost impossible. 

All that doesn't even take into account another issue that all umbrellas face: wind! They're wind traps, and lead to blowdowns.

 

Instead I recommend you make your own white diffuser system. They give good soft diffused light, they're easy to use, and they don't lead to blowdowns. I've made several variations and I demonstrate them on YouTube and my Gumroad video about sketch easels.