EXPLORE SCIENTIFIC 1.25" H-Beta 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 O-III filter uses a characteristic property of the so-called emmission nebulae. Those objects glow in special colors, the so-called emmission lines. Those emmission lines are linked to chemical elements - in this case oxygen. The EXPLORE SCIENTIFIC O-III nebula filter blocks all other colors (and thereby nearly all of the artificial light) and only the two emmission 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 filters come 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. FEATURESenables the observation of so-called emmission nebulaeblocks almost the entire artificial lightonly the two emmission lines of the oxygen passes the filterband pass width: 6.5 nmnarrow band version for difficult urban conditionsallows more contrast for faint deep sky objectsideal for use near cities, in heavy brightened skiesindividual test certificate included to guarantee you receive a premium filterSCOPE OF DELIVERY1x 1.25" O-III nebula filter

NOTE: This item is a used or returned product. This means: The item may show slight signs of use; some accessories may be missing; the packaging may differ from the original packaging. Please note that refurbished items generally come with a 12-month warranty.

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 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 Lets only the emission lines of ionized sulfur at 672 nm pass Transmission bandwidth: 12 nm Allows for more contrast in faint deep sky objects Ideal for use near cities, in slightly brightened skies Individual test certificate included to guarantee you receive a premium filter SCOPE OF DELIVERY 1x 1.25'' 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 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 O-III 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 oxygen. The EXPLORE SCIENTIFIC O-III nebula filter blocks all other colors (and thereby nearly all of the artificial light) and only the two emmission lines of the oxygen 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 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 emmission nebulaeblocks almost the entire artificial lightonly the two emmission lines of the oxygen passes the filterSCOPE OF DELIVERY1x 1,25" O-III nebula filter

High power eyepieces (e.g. 3mm to 10mm) are used not only for obvious observations of planets and double stars, but can be employed for bright, compact deep sky objects. Not only will the scale of an object like a planetary nebula or globular cluster be impressive as it fills the eyepiece FOV, but the background sky will be very dark as the contrast effect increases with added magnification, provided that the atmospheric seeing conditions are favorable enough to reveal a sharp image. The 6.5mm is a popular choice for a wide variety of telescopes, producing some of the highest magnification views that most astronomers will observe at.Comfort, Quality, Value. The Explore Scientific 52° LER Series Most short focal length eyepieces are excellent flat-field multi-element oculars that can transform your visual astronomy experience. With an apparent field of view of 52 degrees, these eyepieces offer incredible value in a very nice eyepiece. Expect exceptional quality and value versus a comparably priced Plossl.  These eyepieces are the choice for observers wearing glasses - with excellent performance and durability. The rubber inlet and the foldable eyecups make handling and using in the field easy. The patented EMD-coating produces high contrast images and prevents reflexes and ghosting. The argon purging effectively prevents internal fogging, and you don´t have to deal with dirt, fungus or cleansing fluids getting between the lenses. The eyepieces are sealed - this makes sure you will be able to enjoy these eyepieces for many years to come.SPECIFICATIONS:Large eye distance, large field and great image sharpnessExcellent viewing position for people with glassesExcellent field sharpness even with fast optics52° apparent field of viewArgon-purging prevents internal fogging, the sealing facilitates cleaningPatented EMD"-coating to maximize contrastBlackened lens edges to avoid reflexesAll eyepieces of this series are parfocalStainless steel barrel with conical security cutoffDust covers and protective bag includedSCOPE OF DELIVERY:52° EyepieceDust coversProtective bag