A range of Precision Loupes for the Gemmologist
The LB010-Triplet are leightweight binocular magnifying eyeglasses, giving stereoscopic short distance viewing with a working distance of 270-300mm, and an adjustable eye distance of 56-74mm. The precision optics of these eyeglasses provide an excellent stereoscopic view, with a great depth of sharpness and an excellent surrounding field of view. Magnification is 2.3x.
All Krüss loupes have achromatic (distortion-free) and aplanatic (free from spherical aberration) lenses, and offer magnification ranging from 10x to 28x.
For prices and availability information on binocular magnifying eyeglasses and loupes, please contact your nearest Krüss distributor, who will be delighted to help. For full technical specifications, please download the relevant datasheet here.
You can find our Loupes in the Gemmo-Shop.
The loupe: a small, effective device
A loupe (or hand lens) is a simple, small, handheld magnification device, its lenses are contained in a cylinder or cone. The lenses allow our eyes to focus on an object at a much closer distance than normal, making it appear larger, showing detail we would not normally see.
Distortion can be a problem with single lens loupes, normally a triple lens loupe is recommended to overcome this – the three lenses are placed together so that distortion and colour problems are corrected.
Magnification is shown by an ‘X’, which denotes ‘times’. For example, a 5X loupe makes an object appear five times its actual size, and a 28X loupe shows the object twenty eight times its size.
Focal length, field of view and depth of field are explained as follows: Focal Length is the distance you hold the loupe from an item in order to get the best focus and magnification. As magnification goes up, focal length goes down. Field of View is the size of the area you can see through the lens. The diameter of the lens affects the field of view, likewise the magnification power. The higher the power, the smaller the view. Depth of Field indicates how far you can move the loupe towards or away from an item and still have it in focus. The higher the power, the shorter the depth of field.
Loupes are widely used in the jewellery industry, but other sectors such as watch making, geology, biology, ophthalmology, dentistry, surgery, photography and printing also make good use of this small, but effective, magnifying device.
Traditionally, jewellers use a loupe to magnify when examining stones and hallmarks. The standard for grading diamonds is 10x – the criteria being that blemishes and faults must be visible at this magnification to qualify for grading.
It may be advantageous to have both hands free, for example in watchmaking and dentistry, this is when the eyeglass magnifier plays its part – in simple terms they are a glasses with magnified lenses. Some dental loupes are flip-ups, two small cylinders, one in front of each lens of the glasses. Others are inset within the lens.