Folding Magnifying Glasses
Low Power Hand Held Magnifier Reveals Details of Plants and Animals
Adults and chilren who are interested in the natural world, be it botany, zoology or geology, ought to carry a good quality hand lens in their pocket at all times.
How to Choose a Hand Lens
Magnification - The first decision must be what magnification. Very low power (typically X3) is useful for looking at medium sized creatures or structures. These have the advantage that they normally have good field of view and depth of focus. For general use naturalists often go for a slightly higher magnification than this (X8 or X10). These are smaller and have more sophisticated optics – they are also more expensive. Maybe avoid the decision by buying one of each?
Plastic or Glass Lenses - Plastic lenses are never as clear as those made of glass, and they scratch too easily. A good quality X10 hand lens (or Jeweller’s Loupe) will have coated glass lenses and give a very clear image.
Folding or Non-Folding – Always go for one that folds snugly into a robust unit. This will stop it getting scratched when it rattles around with keys and coins.
Try Before You Buy
Make sure the depth of field is adequate, and focus on a small object. Keeping the image centred on this, check that the rest of the field is clear and free from colour distortions. A good tip is to find a lens where nearly the whole field is in focus when you look at your own fingerprint. This is not a very expensive piece of equipment and it usually pays in the long run to get the best that you can afford (one good one is better than a pocketful of poor ones).
How to Use Your Hand Lens
The lens should be held right up to the eye, and the object of interest must be very close to the hand lens (an inch away from it). When not in use it is sensible to fold the lens away to stop it being scratched when in the pocket, and to stop it concentrating the sun’s energy and risking fire when left lying around.
Things to Look At
Anything that takes your fancy – but most people begin by looking at things lying around in the house! After fingertips have a look at the details of a coin or postage stamp, maybe look closely at a photograph or piece of newsprint. When using the lens has become second nature move on to looking at small animals, or small parts of larger ones
