The stereo microscope is the most commonly used microscope. This applies to both the materials science and biological science fields. My past career as a materials engineer depended critically upon the three dimensional imaging of the stereo microscope for studying metal parts and fracture surfaces. Unfortunately our clients had no readily available way to view stereo pairs, so stereo pair recording was not done. Likewise, our electron microscopes were not equipped with costly eucentric stages, which make stereo pair recording easily done.