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Using a Magnifying Glass

Tom Becker

Even the most eagle-eyed professional numismatists will sometimes "cheat" and use a magnifying glass to supplement their normal vision. The really intelligent pros put vanity aside and realize it is worth the time and effort to get the best possible look at any potential purchase.

Is it really necessary to view a coin so carefully now that the grading services have done all the work for us? Even if you have never disagreed with a grading service opinion, it might be wise to take a peek through the plastic to determine why a coin you're interested in deserves a certain grade. Many collectors have preferences concerning flaws. Hairline scratches may not bother you, but such defects may drive me crazy. That a coin was given the MS-63 grade because it has a scratch well hidden on the reverse or the same size mark on the cheek can be quite important and have a profound influence on desirability and value. The grading services have done most of the work for us, but I see no good reason to be a sight-unseen or blind buyer.

All "Glasses" are Not Equal!

You can obtain a dime store quality magnifying glass for only a few dollars or spend hundreds for the same size, similar looking equipment. The quality of the lens can range from plastic filled with distortions to glass ground for use in the finest cameras, telescopes or microscopes. The difference has to do with the clarity of what is being viewed. The value of magnification is greatly diminished if the object being viewed is distorted or blurred.

Using an inexpensive magnifying glass defeats much of the purpose and can also cause considerable strain on the eyes. In the coin hobby most numismatists will be satisfied with magnifying equipment equal to what jewelers or those examining small parts in industry might use. How frequently you use this equipment is also a consideration. A person working under magnification on a daily basis can justify the cost of better quality lenses.

How to Use a Magnifying Glass:

There are many different types of magnifiers. I will only mention those of the hand-held, portable variety, which fits easily in one's pocket or purse. When using these devices the magnifier is held a short distance (perhaps an inch or less) from the eye and the object being viewed is brought to it to obtain the proper focus. If you watch someone trying to view coins with a glass for the first time they will often make the mistake of placing the object on a table and then moving the magnifier forward and back. This procedure will never work well. When the object can't be picked up, such as a coin inside a display case, then the magnifying equipment is still held near the eye and the viewer's body is moved downward to obtain proper focus.

That vision varies with the individual means not everyone will hold a coin the same distance from the magnifier's lens to obtain the best focus. A person who wears eyeglasses may remove them or leave them on when using a magnifying glass. In every case some experimenting and practice is necessary. After viewing a few hundred coins how you hold a particular magnifier and coin will become second nature.

I would strongly suggest against spending a significant amount for a good magnifying glass (it seems these days the "good" range starts at about 20) without trying it first. This can often be done at a coin show where dealers and collectors will probably be happy to let you take a quick peek with the equipment they use. Those who sell this equipment should also let you to "try on" different products. These vendors may also provide valuable information to help you make the best choice.

Don't expect anyone to let you borrow his or her personal magnifying glass. Collectors and dealers often develop strong preferences, if not a dependence on a particular type of magnifier. Their eyes have become used to working with the image the magnifier provides and their brain has learned to properly process this information. A good quality magnifying glass is a tool that can last a lifetime. I know of one serious buyer who left a coin show after losing his magnifying glass. He simply couldn't trust himself to buy expensive coins without it! Using this equipment is a complicated and often subtle process. It is much like the favorite trusted hammer used by a skilled carpenter or the type of shoes worn by a professional athlete.

Exploring the Many Options:

There isn't a best magnifying glass for everyone. There are some close fits that seem to meet the needs of most coin collectors.

General Viewing: Most of the dealers and collectors I know prefer a magnifier with 5x power with a lens approximately 1 inch it 1.5 inches in diameter. The 5x indicates that when properly focused the surface of the object will be magnified about five times normal size. I say about becausethe quality of the lens and the person using the equipment can alter this performance. As mentioned previously, the clarity of the image can vary depending on the quality of the lens. The size of the lens enables the viewer to see a fairly large portion of the coin. The coin is simply movedto view other portions of the surface.

In some cases, depending on the quality of eyesight, some might prefer a 7x magnifier with a somewhat smaller diameter lens. Magnifiers with less power, including those large units often used as an aid when reading, generally don't provide sufficient detail for closely viewing flaws on coins. Such equipment might be best limited to verifying dates and mintmarks or for scanning large quantities of coins to detect rather obvious flaws.

Specific Viewing: To positively detect counterfeit coins or those with altered or added mintmarks stronger magnification is often used. The professional numismatist and active collector may arm themselves with two or three magnifying glasses each best suited to perform a specific task. It is a mistake to assume that greater magnification is automatically better.

Some Practical Hints:

The best magnifying glass in the world won't work in the dark. Having a proper light source is critically important. The major buyers at coin shows always try to create a standardized environment in which to view coins. The intensity and type of light can be extremely important. The consistency of the light and how shadows are cast must be considered. There are many variables, but I think it is generally accepted the pure sunlight is not a good source to use when viewing coins. Florescent light can also play tricks with our eyes when viewing coins, with our without magnification. Incandescent light provided at close range from a 75 or 100-watt bulb seems to be the choice for most of the pros. In saying this, I'm keeping in mind we can all learn to adapt to various circumstances and learn to effectively live with them.

There are several brands of hand-held magnifiers that come with a built-in light source. When a button is pressed a beam of light is projected toward the object you are viewing. I've used these devices before and find they work reasonably well at coin shows where the light can vary tremendouslyfrom one portion of the room to another and even from one bourse table to the next. Such equipment is less necessary at home or in the office where proper and consistent light can be provided in the area where you view coins.

A decade or so ago, some dealers experimented with the use of halogen lighting. I tried this as well and found it to be too intense. Under this light everything looked bad! I did find that halogen light was excellent for detecting hairlines on coins. If you are primarily interested in proof coins viewing them under halogen light may be productive. Certainly others may have a completely different experience, but I found working under halogen light for even an hour or two was quite a strain on my eyes.

This may seem like a strange statement, but it is possible to examine a coin too closely. Under 10x magnification a coin that looked appealing to the naked eye might seem horrible. Tiny flaws become major ones. If you are only prepared to accept coins that appear "clean" under 10x magnification then you will find few pieces that please you.

It is also important to use a magnifying glass to view the entire coin and to take advantage of this important tool by tipping the coin and rotating it to see the surfaces from different angles. When a coin is viewed straight on hairlines are often less noticeable. Turning the coin slightly is often necessary when checking for this common flaw.

A magnifying glass should serve as an accessory and tool, not a crutch. If you watch the professional coin buyers you should notice that many of them first examine a coin using unaided vision. They may then "put a glass" to certain coins to confirm or refute their initial opinion. Once the closerexamination is completed they will often give the coin another look without the aid of magnification.

Based on the length of this article, I hope you share the opinion that selecting the right magnifying glass and using it properly offers an important advantage to every numismatist. Small differences matter in our hobby and we need to see them.


Tom Becker is a regular contributor to the Canadian Coin Reference Site, you can direct your questions directly to Tom easily by or visit Tom's website @


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