GETTING A CLOSER LOOK
Raising or lowering the slide platform will focus the image of the specimen
DID YOU KNOW? The first recorded attempt at using light to magnify images dates to the 1st century CE
Dutch spectacle-maker Zacharias Janssen is credited as the person who put together the world’s first two-lensed microscope around 1600, which could magnify an object up to 30 times. Since then, the instrument has evolved and diversified dramatically to offer extraordinary magnifications and clarity. The world’s highest resolution microscope, which uses a method called electron ptychography, can magnify atoms 100 million times. However, the microscopes found in a high-school laboratory are usually compound light microscopes with a maximum magnification of up to 1,000x. To achieve a high magnification, optical microscopes use a series of lenses that alter the path of light to produce an enlarged image of a specimen. The lenses are biconvex, meaning both sides are curved. When light passes from the specimen towards the eye, it’s refracted by the shape of the lens. Lenses closest to the specimen, called objective lenses, invert and magnify the image, which is further magnified by a lens in the eyepiece. The combination of these lenses provides the overall magnification of the microscope. For example, if the objective lens gives a magnification of 10x and the eyepiece gives the same, the overall magnification would be 100x.