One of my favorite shooting techniques is focus stacking. Many pictures on [email protected] site are made using this technique. I use Helicon Focus for post processing and even though this program has camera control built-in, it obviously requires a computer close to the object of shooting. In order to be able to control my camera in the field, I wanted to replace a laptop with simple lightweight controller able to move focus of camera lens and take pictures between steps. In this article, I will show how to build one from Arduino, USB Host Shield and several small parts.