EXPLORE SCIENTIFIC 2" S-II Nebula Filter 6.5nm

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 bejond the solar systems enourmously. Depending on the type of the celestial object it is possible to increase the contrast dramatically by blocking the annoying artifical light. The Explore Scientific H-beta filter uses a characteristic property of the so called emmission nebulae. Those objekcts glow in special colors, the so called emmission lines. Those emmission lines are linked to chemical elements - in this case hydrogen. The Explore Scientific H-beta nebula filter blocks all other colors (and thereby nearly all of the artificial light) and only the emmission line of the hydrogen can pass the filter. The result is astonoishing: suddenly nebulae are visible at locations that were completely empty without filters. In suburbian skies for example the horsehead nebula is almost not visible with a 300mm 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.

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

​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 streetlights. 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 S-II filter uses the property of the so-called emission nebulae. These objects glow in certain colors, the so-called emission lines. The emission lines are associated with certain chemical elements - in this case ionized sulfur. The EXPLORE SCIENTIFIC S-II nebula filter blocks all other colors (and thus almost all artificial light) and lets only the emission lines of ionized sulfur at 672 nm through. The effect is amazing: suddenly, nebulae become visible in places that appear completely empty without the filter. In slightly brightened skies, many planetary nebulae, emission nebulae and supernova remnants can be seen without any difficulties using this filter. A must for every visual observer and for astrophotography.EXPLORE SCIENTIFIC nebula filters come with an individual test report - so you can be sure to get high quality filters.FEATURESSimplifies the observation of planetary nebulae, emission nebulae and supernova remnantsBlocks almost all artificial lightOnly lets the emission lines of ionized sulfur at 672 nm pass Transmission bandwidth: 12 nmAllows for more contrast in faint deep sky objectsIdeal for use near cities, in slightly brightened skiesIndividual test certificate included to guarantee you receive a premium filterSCOPE OF DELIVERY1x 2'' S-II nebula filter

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

Besides air turbulence, the brightening of the night sky is the biggest obstacle to observing faint objects beyond the solar system. Street lamps and other artificial lighting mean that the sky in human settlements is no longer really black. This affects the contrast and thus the perception of deep-sky objects. Depending on the type of celestial object, however, part of disturbing artificial light can be filtered out, making it easier to observe fainter targets.The EXPLORE SCIENTIFIC CITY LIGHT SUPRESSION - or CLS - filter uses the fact that the artificial lighting is not evenly distributed over the entire spectrum. These colours - in the case of the EXPLORE SCIENTIFIC CLS nebula filter, above all the typical colours of mercury and high-pressure lamps, used in street lighting - are suppressed, but the emissions of deep-sky objects are allowed through. With a slightly brightened sky, some relatively bright deep-sky objects are practically invisible with a telescope, for example the large galaxy M101. Using this filter makes observation much easier. A must have for any visual amateur astronomer.  The CLS can also be used as a useful photographic filter - helping to improve the quality of your telescopic deep sky photos.The EXPLORE SCIENTIFIC nebula filters are delivered with an individual test report - so you can be sure of receiving high-quality filters.SPECIFICATIONS:eliminates disturbing light - e.g. from street lightingenables observation of faint deep sky objectsWHAT'S INCLUDED:1x nebula filter