Saulius made a DIY PCB inspection microscope and wrote a post on his blog about it:
Despite how good microscope you have, stand is still very important part of final assembly. And while there are many commercial ones made of cast iron, they might cost more than a microscope head itself. I decided to make stand from wildly available material laying around – it’s MDF (Medium Density Fiberboard). Advantages – stable over time if not exposed to water, dirt cheap, easy to process.
DIY PCB inspection microscope – [Link]