Commercially we tend to use some conventional symbols, as an instance x2-x3-x6 or x5-x7-x10, to identify the magnifying power, even though they do not refer to the real enlargement of the lens; they are just meant to represent a gradual scale of comparable values. The enlargement a lens provides is due exclusively to the curving the glass has: the more curve it is, the larger the image is reflected.
The lenses usually employed in this market are the following:
X2 – X5: Lens curving radius = 800mm
It is a quite weak magnifying, but still allowing to focus relatively far from the lens, suitable for operations such as shaving or makeup.
X3 – X7: Lens curving radius = 400mm
Great enlarging, but requesting a certain proximity of the face to the mirror. Perfect for a refined make up and useful for those who suffer from long-sightedness
X6- x10: Lens curving radius = 300mm
The best magnifying power a curved lens can provide.Very useful for those who suffer from a quite strong long-sightedness, so able to have make up without glasses.
KOH-I-NOOR LENSES QUALITY
One of the most important features of a magnifying lens is the absence of distortions in the image reflected. To ensure this quality and function, all KOH-I-NOOR lenses are cut from spherical caps of big dimensions, conversely from the cheaper models cut from a single piece which cause distortions in the centre but also at the side of the lens.
All magnifying lenses of Koh-i-noor are made in EU.