I recently had been using the smart-object stacking mode in CC 6 to create star trail exposures ADOBE TV – tutorial (Warning««this guy is goofy)– you can apply the same technique bracketing your focus as well in macro or micro photography to extend the depth-of-field. Similar to HDR photography the stacking modes in photoshop offer a versatile and easy to use automation of blending modes Helicon Focus is a program specifically designed for this task and it also creates a 3D rendering of your image as well which is pretty unique. With a little work you can create a true 3D model of any object and then bring it into a program such as Maya to fine tune the enviornment.
3D rendering using Helicon Focus from Christopher Lisle on Vimeo.