The human eye has a much greater dynamic range than photographic film or CCD/CMOS digital sensor / digital back (dynamic range means the ability to visualize a wide range from darkest to lightest shades of the light).
Because this fact, it often happens that high dynamic scene that we see by simple human eye after shooting with camera lost most of its dynamic range, for example dramatic textured clouds are on the digital photo visible only as a large white area, in photographic terminology: "over-exposed area". Upper part of the image is very light and lower part is very dark.
This negative fact is present because digital sensor or film can not record images with a large dynamic range such as a human eye. Due to this, a photograph taken outside (outdoor) is sometimes useless when a filter is not used. And that is why almost all outdoor photographers (landscape, architecture or nature photographers) uses filters so-called gradual ND filters (Neutral density filters).
The neutral density filter is a neutral gray color which reduces (amount of of light passing through a filter) and neutrally darker the upper part of image as far as possible without affecting its color tone (neutrality). The result is often stunning - "blow" the sky will disappear, the sky and cloud structure becomes visible, three-dimensional lattice, while the very bottom (landscape) remain ideal exposed (not over exposed, not dark). Moreover, the effect is very natural, and the use of the filter is not noticeable.
PROPERTIES OF THE CR-39 MATERIAL:
CLASS A OPTICAL MATERIAL
The material used for the production of 84.5mm filters is commonly used worldwide for the production of corrective eyeglasses, which shows the extraordinary optical properties. While conventional optical glass was used in eyeglasses in the past, the trend of the 21st century is called organic glass, which offers almost identical optical properties, as well as significantly is lighter in weight, more flexible, and more resistant. Although these are some characteristics found in the production of eyeglasses, most photographic filters which are currently on the market use this material as well.
Materials which are used in various areas of the military and aviation are usually known as the toughest, highest quality and often unavailable to the general public. Organic glass is used in the manufacture our filters and are also commonly used in military aircraft to cover the cockpit. This material is highly scratch resistant when washed, resistant to very high pressure, very elastic, light weight, and has excellent optical characteristic, anti-reflective ability and more! Typically, the durability of these materials is appreciated in situations such as combat pilots operating in difficult conditions and professional photographers shooting during harsh weather
conditions and or/time stress where filter can be scratched or damaged if it was made from basic plastic material, not organic glass.
REFRACTIVE INDEX AND ABBE NUMBER
The material used in these filters (84.5mm) achieves the best features in a variety of other optical parameters such as Abbe number with a value of 58, guaranteed minimum (hardly any) negative impact on the chromatic aberration (which is often a negative phenomenon cheap lenses) and more. If we combine the optical properties with mechanical properties of flexible polymer / monomer we get almost perfect material, and that is what we
HIGHLY SCRATCH RESISTANT MATERIAL
While ordinary plexiglass or resin materials can be relatively easy to scratch, our organic glass is completely a different case. Our filter material is characterized by extremely high scratch resistance and common materials such as fingernails and sharp objects (plastic holder) make it almost impossible to scratch. This is another reason why it is used not only in correction glasses but also the military. More information about this type of scratch resistance of organic glass can be found in the FAQ section.
HIGHLY ELASTIC MATERIAL
Most ordinary glass breaks easily when it falls on the ground/floor, but organic glass is very flexible. Due to the glass being flexible, if dropped on the ground/floor or you or handle insensitively, it most likely will not break or shatter.
MADE IN EUROPEAN UNION
All of our products are completely hand-made in the European Union. Using the most advanced manufacturing processes, strict compliance adherence with European directives and legislation. Our trained team of technically skilled manufacturing specialists provide a guaranteed premium quality product. Some might question why certain products such as Swiss crafted watches are manufactured only in Switzerland and not outsourced in Asian country for better prices. Our response is that highest quality products with high value, where every smallest detail matters can be made only completely in-house, under the strict supervision of pedant specialists
working several years in hi-tech optics industry. Simply high quality of our products and reputation of our brand is much more important than reduction of production costs by outsourcing in developing countries (Vietnam, Thailand, China) by less skilled staff.
We take pride in our work, in our products and we are proud to say they are all hand-made manufactured in the European Union.