Kowa uses the fluorite crystal exclusively in its flagship spotting scope and large binocular models. The fluorite used as make an optical lens is an artificially grown mono-crystal with "ultra-low dispersion", a characteristic that ordinary optical glass does not have.
It is an ideal lens material that almost completely eliminates chromatic aberration (color blur). The fluorite crystal produced by the sophisticated processing technology that Kowa has accumulated over the years guarantees the ultimate viewing experience.
Dual focus mechanism (Quick and fine focusing)
The well established Kowa focus system has progressed to a new dual focus system. The quick focus, with a large and easy to turn knob, will focus from infinity to five meters in two revolutions.
The fine focus, with smooth movements and pinpoint accuracy, is extremely useful at high magnifications and for digiscoping systems.
One of the major causes of deterioration of viewing quality in optics is chromatic aberration (color blur). Chromatic aberration occurs due to the dispersion of light and the different wavelengths of light focusing on different positions, resulting in a red or purple fringing around the image. The optimum optical material to minimize chromatic aberration is fluorite crystal.
A fluorite crystal with extremely low dispersion characteristics is used for the convex lens of the KWA-773 PROMINAR models. In place of an ordinary optical glass lens, the concave lens paired with the fluorite crystal lens is made of glass with special dispersion properties to reduce the chromatic aberration to a further degree.
This combination of fluorite crystal and glass with special dispersion properties nearly eliminates chromatic aberration and redefines the standards of color brilliance.
This technology is the result of many years of optical design and has realized great reduction in chromatic aberration, while maintaining a large diameter lens and high contrast images when compared with conventional models.
The XD lens used in the KWA-773 PROMINAR models has characteristics similar to those of fluorite crystal to significantly reduce the chromatic aberration. All lenses are environmentally friendly Eco-Glass. (Eco-Glass is an environmentally friendly glass that does not contain lead or other harmful substances.)