How to identify coins- the non-invasive way

Your computer can help you identify otherwise unreadable coins. I hit upon this method after having wiped out any chance of evaluating three coins that must have been at least 200-years-old. At first glance, even when they were partly covered with soil, I could see vague stamped outlines on their obverse sides.

The coins looked interesting, but obviously are of no great financial or numismatic value. So I immediately set to work removing all tarnish with a metal cleaning paste. The result was a shiny, blank, planchet. Somehow, the tarnish had made the slightly raised markings visible.

But now they were gone, and no effort to tint the coins artificially with ink or graphite did much good. I had to give up on them. (If you decide to clean a badly worn coin with a chemical polish, do so minimally – only enough to allow you to identify it.)

Later, I took similar finds, soaked them in olive oil for a week, and then cleaned them with a toothbrush and castile soap. This did no damage. And it was possible to squint through a magnifying glass and see, or imagine, what was there – although the designs often appeared to be unlikely for the 18th century (a 747, or Babe Ruth at bat).

Later, while electronically processing some faded family pictures, I asked myself, “Why not do this with coins? How can it hurt?” And the experiment worked – about half the time (because, after a certain amount of surface deterioration you just can’t do any more without professional training and equipment). Luckily, as a coinshooter, you need no special skills or exotic apparatus to scan in and observe coins on a computer screen. But you do need a computer, a scanner or digital camera, and a rudimentary graphics program that you probably have already and may not know it.

Scanners and digital cameras usually come with suitable software on a compact disk packaged with the equipment, and most computers incorporate a graphics program or two as part of the operating system. For example, computers running in a Windows XP environment typically include Microsoft Photo Editor and Paint programs that allow you to vary the brightness and contrast of the displayed image and to change its size. Apple and other systems offer something comparable. These are suitable for experimentation, and often will prevent you from getting disgusted enough with the specimen to ship it to the wire factory.

All you have to do is scan or photograph the coin, load the image file into the computer, assign it a meaningful name, and display it on your screen. You can now put the coin away; you’re done with it.

Interactive Adjustments

Using the graphics program, slowly adjust the brightness, contrast, balance, and image size as required. The adjustments interact, and it’s advantageous to play with them until something recognizable appears. If you’re happy with the result, save the file under its original name, or assign a new one (thereby allowing you to keep both images). Otherwise, don’t save the file.

You can go through the same procedure with as many coins as you like. Nothing happens to the coins themselves, and sometimes you’ll be able to identify what they are.

Sophisticated graphics programs (e.g., Corel or Adobe) used by artists allow you to arrange virtual lamps and spotlights to create implied shadows, and to perform other interesting maneuvers such as sharpness adjustments.

But these special programs are expensive, and normally not worth the purchase price just to identify tarnished coins.

Other programs (e.g., Microsoft Picture It) that are not as elaborate still offer various controls not included in the free ones. I recommend, though, that you play with the capabilities you already have, and see what they do. You’re the only one who can judge if it’s worth the bother.

You’re also the only one who can judge whether to use a scanner or a camera. For any specific coin, one might be preferable to the other. Again – don’t rush out to buy new equipment.

Try what you now own. If you use a camera, watch out for reflections and hotspots from the flash. Snapping the picture outdoors on a clear day might be better. Also be careful about focus and distance from the coin. These things are not usually a problem with a scanner.

I store my non-numismatic coins in 2×2 folders, and find that it isn’t normally necessary to remove them to get a good image. Try it both ways.

You have nothing to lose but a little of your time. And if it works at all for you, you’re way ahead of the game.


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