It was definitely a real instrument. But there were several problems that derailed development. One problem is that Nemes didn’t understand the physics behind the operation of the microscope. He also had a lot of trouble actually getting the microscope to work — it had a tendency to fail during demonstrations. They also never had a reliable way to calibrate how much specimens were being magnified (the microscope didn’t use traditional “optics” to generate magnification). And if you look at a lot of the pictures taken using the Nemescope, what you are really seeing is empty magnification. The device could achieve greater magnification than the electron microscope (because there really isn’t a limit to how much you can magnify an image, even with existing microscopes), but you can’t make out an details of what was being magnified. If you take a look at pictures of enzymes taken with the Nemescope, they look like blurry halos of light. If you can’t actually make out the structure of something, then achieving that level of magnification is useless. The other problem with Nemes is that he was a severe alcoholic and sold people a stake in the microscope even though he was actually only an employee of the company that owned the rights to his invention. Several companies were given the opportunity to evaluate the microscope but they always walked away because of the technical problems with the microscope and the fact that Nemes was not reliable after about 1958.