Clarity Grading With a Loupe (6.13)
When using a loupe, it is still important to make sure the light source is bright white light. Before bringing your 10x fully-corrected folding triplet loupe up to your eye, make sure the lenses are clean. With the loose diamond held in tweezers in your left hand (right hand if you are left-handed) and the loupe held in your right hand (if your right-handed), rest one hand upon the other to steady yourself. If you are at a desk, rest both elbows to maintain a solid platform while grading the diamond. The general rule-of-thumb is that right-handed people have a stronger right eye, but this is not 100% true, so experiment with both sides to see which gives you the best viewing and the most comfort. Always leave both eyes open to relieve unnecessary eye strain and for stereoscopic viewing. With your loupe hand resting behind your tweezer’s hand, you will be able to find the focus with the diamond itself. The focal point will occur at about one inch from the loupe.