I have a 20X loupe, specifically made for examining internal flaws in gemstones, but it is perfectly suitable for examining to the level of fine detail on coins as shown in this thread.
It has a very narrow depth of field, so the facet edges of the gemstone can be deliberately out of focus, whilst at the same time, an internal flaw in a gemstone can be examined in sharp detail.
20x, I have found, is about is as much magnification you can use with a hand held lens. If more detail is required, it is off to my microscope.
BTW, If I want to have a look at the grain structure of the metal in the surface of the coin, I can ask my next door neighbor to examine it with an electron microscope. OK, if the supply of liquid nitrogen is available for it! He acquired the device very cheaply as a disposal from his work place. He is a forensic scientist, employed by the government.
Posted 04/28/2011 7:12 pm
