EXPLORE SCIENTIFIC 2" H-Alpha Nebula Filter 7nm

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 when 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. FEATURES Simplifies the observation of planetary nebulae, emission nebulae and supernova remnants Blocks almost all artificial light Only lets the emission lines of ionized sulfur at 672 nm pass Transmission bandwidth: 6.5 nm Allows for more contrast in 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'' S-II nebula filter

Universally usable variable polarizing filter with a  2" filter thread.This variable polarizing filter allows for a continuous adjustment of the image brightness. This is very helpful to level strong differences in contrast of different observation objects individually. Particularly for lunar and planetary observations but also for solar observations this filter prevents an outshining of details.Solar observations ONLY together with an adequate solar filter !!! Particularly when a Herschel wedge is used and with large objective lens apertures the use of the variable polarizing filter can reduce the brightness of the observation object to a confortable level. The large adjustment range of 40% to 1% light transmission and the neutral grey filter effect create a comfortable and unadulterated image.The handling is very simple. The desired filtering level is set by turning the two sides of the housing against each other.A 2.0" filter thread on both sides (female/male) allow for the simultaneous use of additional colour filters.FEATURESvariable polarizing filterindividually adjustable image brightnessmade from high-quality optical glassblack anodized aluminium housing2.0" filter thread on both sidesSCOPE OF DELIVERYpolarizing filterprotective box