Every day, new technology creates smaller and smaller materials and components. In many industries these parts require high magnification, sometimes up to 1,000X, to see submicron features. This is accomplished using a compound or upright microscope, where the user can select the objective lens. But in many applications, a stereo microscope might be a better choice.

Why would you need a stereo microscope? Many times we’re looking at objects or features that are millimeters in size and have surface topography. In these cases, a magnification of 10X–50X is more than enough to do the job, and that’s where stereo microscopes offer many benefits over a compound microscope.

Galilean optics

Let’s first look at the stereo aspect. We all know that our brains interpret three dimensions by using our two eyes and processing the differences between what each eye sees. Why would you want to give this up? Many stereo microscopes utilize Galilean optics (figure 1), i.e., two independent and parallel optical paths that are focused through a single objective to a focal point on your sample. This provides the same different angle to each eye, and thus the same stereo effect.

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