Why So Many Different Coin Magnifiers?
Basically, the purpose of a coin magnifier is to enlarge the image of the coin so that its details may be seen more clearly. This is a function of the power of the magnifier. However, three other factors affect the performance of a magnifier and its suitability for certain jobs: field of view, depth of field and working distance (focal length). The four factors are interdependent; if the power is increased, the other three become smaller, and so forth. In selecting a magnifier, you should consider all four factors.
