Stereo microscope

The instrument uses two separate optical paths with two objectives and eyepieces to provide slightly different viewing angles to the left and right eyes.

[1] Stereomicroscopy overlaps macrophotography for recording and examining solid samples with complex surface topography, where a three-dimensional view is needed for analyzing the detail.

[citation needed] The first optically feasible stereomicroscope was invented in 1892 and became commercially available in 1896, produced by Zeiss AG in Jena, Germany.

At the marine observatory in Concarneau on the Bretton coast, led by the former director of the Muséum national d'histoire naturelle, Georges Pouchet, he was influenced by the new scientific ideals of the day, namely experimentation.

While dissection of dead and prepared specimens had been the main concern for zoologists, anatomists and morphologists, during Greenough's stay at Concarneau interest was revived in experimenting on live and developing organisms.

In order to yield images that would do justice to the three-dimensionality and relative size of developing invertebrate marine embryos, a new microscope was needed.

Greenough took action and, influenced by his Concarneau colleague Laurent Chabry’s attempts to construct intricate mechanisms to turn and manipulate the live embryo, conceived of his own instrument.

Building on the recent discovery of binocularity as the cause of depth perception by Charles Wheatstone, Greenough designed his instrument with the phenomenon of stereopsis in mind.

Small specimens necessarily require intense illumination, especially at high magnifications, and this is usually provided by a fibre-optic light source.

Video cameras are integrated into some stereo microscopes, allowing the magnified images to be displayed on a high resolution monitor.