Recently, a question popped up on the Microscopy mailing list (http://www.microscopy.com) regarding the use of CCD cameras in a TEM that can be summarized as “why use a 4 megapixel camera instead of simply magnifying twice as much and use a 1 megapixel camera?” One of the assumptions was that the computer screen used to display the image only has so many pixels anyway (usually in the order of one megapixel), that even printers could not print out the image in sufficient resolution, and that stretching the image to render all available pixels would “change the magnification”.

It is our experience that these things can be confusing to beginning microscopists and casual users of an instrument, and this was confirmed by several people on the mailing list. So, how best to explain the concepts “magnification” and “resolution”, which beginners often consider interchangable?