EXPLORE SCIENTIFIC 2" S-II Nebula Filter 12nm

One of the most important obstacles for the exploration of the night sky is the brightening of the night sky by artificial lights, such as streetlights. The night sky is not really dark in the vicinity of towns or cities, which reduces the visibility of objects beyond the solar systems enormously. Depending on the type of the celestial object it is possible to increase the contrast dramatically by blocking the annoying artificial light. The EXPLORE SCIENTIFIC O-III filter uses a characteristic property of the so called emission nebulae. Those objects glow in special colours, the so called emission lines. Those emission lines are linked to chemical elements - in this case oxygen. The EXPLORE SCIENTIFIC O-III nebula filter blocks all other colours (and thereby nearly all of the artificial light) and only the two emission lines of the oxygen can pass the filter. The result is astonishing: suddenly nebulae are visible at locations that were completely empty without filters. In suburban skies for example the veil nebula NGC 6992 is almost not visible with a 200mm telescope. By using this filter you can see the nebula and its structures without problems. A must for every visual observer. The EXPLORE SCIENTIFIC nebula filters come with a individual test certificate - your guarantee to receive a premium filter.FEATURESenables the observation of so called emission nebulaeblocks almost the entire artificial lightonly the two emission lines of ionised oxygen passes the filterWHAT'S INCLUDED1x 2" O-III nebula filter

One of the most important obstacles for the exploration of the night sky is the brightening of the night sky by artificial lighting, such as street lights. The night sky is not really dark in the vicinity of towns or cities, which reduces the visibility of objects beyond the solar system enormously. Depending on the type of celestial object, it is possible to increase the contrast dramatically by blocking the interfering artificial light. The EXPLORE SCIENTIFIC O-III filteruses a characteristic property of the so-called emission nebulae. Those objects glow in special colours, the so-called emission lines. Those emission lines are linked to chemical elements - in this case, oxygen. The EXPLORE SCIENTIFIC O-III nebula filterblocks all other colours (and thereby nearly all the artificial light) and only the two emission lines of the oxygen can pass the filter. The result is astonishing: suddenly, nebulae are visible in locations that were completely empty without using filters. In suburban skies, for example, the veil nebula NGC 6992 is almost invisible with a 200 mm telescope. By using this filter, you can see the nebula and its structures without any difficulties. A must for every visual observer and for astrophotography. The EXPLORE SCIENTIFIC nebula filterscome with an individual test certificate - your guarantee for receiving a premium filter. This filter's narrow passband of only 6.5 nm bandwidth highlights the faint emission nebulae or makes them visible even under difficult urban conditions. FEATURES enables the observation of so-called emmission nebulae blocks almost the entire artificial light only the two emmission lines of the oxygen passes the filter band pass width: 6.5 nm narrow band version for difficult urban conditions allows more contrast for faint deep sky objects ideal for use near cities, in heavy brightened skies individual test certificate included to guarantee you receive a premium filter SCOPE OF DELIVERY 1x 2'' O-III nebula filter