Multifunctional binocular stereo attachment, c. 1925
After Oskar Heimstädt
This multifunctional binocular stereo attachment was invented by Oskar Heimstädt (1879-1944) in 1920 while employed by the firm Carl Reichert in Vienna (he was also the designer of the first fluorescence microscope in 1911). The apparatus allows stereoscopic viewing through a single objective. It can be used in a number of ways. It can be attached to a typical monocular microscope to serve as a binocular head. In addition, by using the various attachments, it can function as a stereo binocular microscope/magnifier on its own. In the latter situation, the instrument is usually attached to a stand. There are attachments that allow the instrument to function as a low power stereoscopic magnifying glass of very long focal distance and variable magnification. It can even function as a telescope with 3 1/2 times magnification. High powers can be achieved by the attachment of objective lenses.
It is stated that the instrument can be used for biological or metallurgical examinations. It also has some medical applications such as dermatological examinations and with appropriate lighting, it can be used to examine body cavities. The very long focal distances achieved with this instrument make it ideal for dissections.
The apparatus has an eyepiece diopter adjustment as well as a graduated adjustment for the interocular separation. it comes supplied with two sets of matching eyepieces, two tubes that allow low power long focal length variable magnification, another tube that allows somewhat high power magnification and onto which objectives can be attached. Three special objectives are supplied. Also found with the case is a loupe with an attached rod (for attachment to a stand).