How to Use a Microscope to Observe Coins

Select a stereo microscope to get the best results. While a single eyepiece (monocular) microscope will work, a stereo microscope has two eyepieces, allowing you to see the coin in three dimensions and in more detail.

Select magnification levels of between 5x and 30x. Some microscopes have fixed magnification objectives, but those with a zoom magnification---although more expensive---make observing coins easier since magnification is continuous. Begin at the lowest magnification and then gradually increase it.

Adjust focus using the focus knobs. Many microscopes have two knobs: a coarse focus, which should be used first, and a fine focus, which allows you to refine your focus on the object. You will probably need to adjust the focus every time you change the magnification or when using it after someone else with different eyesight.

Begin observing your coins. You will likely see scratches from normal wear and tear. A pattern of scratches can indicate that the coin was polished. On ancient coins you may be able to see tool marks or lead pockets. You can also look for design elements that are hard to see with the naked eye, such as the statue of Abraham Lincoln inside the Lincoln Memorial on a modern U.S. penny. It is also possible to find errors on a coin, which increases its collectible value.

Photograph the magnified images of your coins. Many coin microscopes have a third eyepiece for the attachment of a film or digital camera. Photographs can be useful for recording a coin collection, for sharing with other coin enthusiasts and for advertising coins for sale.