EXPLORE SCIENTIFIC 1.25" CLS Nebula Filter

With the introduction of the 68° Series we are pleased to make two important improvements in eyepiece manufacture, the first being 15 layer Enhanced Multi-layer Deposition (EMD™) coatings on all glass-to-air surfaces to gain maximum contrast, and waterproofing the eyepiece with the use of Argon gas purging instead of standard Nitrogen gas. Although Nitrogen is a fine choice that will last for many years, Argon is a larger molecule that maintains its protective properties over a wider range of temperatures, and is even more resistant to diffusion thereby further extending the protective waterproof environment of the eyepiece body. Through computer-optimized design, a careful selection of optical glasses, and enhanced multi-layer deposition coatings, the Explore Scientific 68° Series™ eyepieces produce long eye-relief and ensure high image-correction, a flat field, and high contrast across the entire image field. An excellent choice for those who make extended visual studies of detail with subtle variations of brightness, and for those who must wear glasses while observing. All 68° Series eyepieces are fully EMD (Enhanced Multi-Layer Deposition) coated and edge-blackened to produce superior contrast.

The three-lens design of the EXPLORE SCIENTIFIC ED-Apochromats provides everything an amateur astronomer desires - at a reasonable price. The construction with Hoya FCD001 ED glass has two air spaces and provides a level of correction so superior to the two-lens constructions, that are common in this price class, that you will see the difference immediately. This excellent optical performance teams up with a high precision mechanics - the result is a telescope on a level that is setting a new standard in it´s price class. Astrophotographers will love this telescope - a optional field flattner is available and makes the telescope perfect even for cameras with a large chip format.These very popular EXPLORE SCIENTIFIC Triplet ED APO Refractors we do offer in 3 different product lines:Essential Line: HOYA FCD-1 Glass lens, AL-Tube, 2.0'' Rack&Pinion Focusser with 1:10, 2.0'' Star Diagonal 99% Reflectivity (see Part No. 0112084(AL), 0112106(AL), 0112132(AL)), 0112155(CF + 3''FT)) Professional Line: HOYA FCD-100 Glas lens, AL/CF-Tube, 2.5'' HEXAFOC Focusser with 1:10, 2.0'' Star Diagonal 99% Reflectivity (see Part No. 0112086(AL), 0112108(AL), 0112109(CF), 0112134(AL), 0112135(CF))High-End Line: OHARA FPL-53 Glass lens, Carbon(CF) Tube, 3.0'' Feather-Touch Focusser with 1:10, 2.0'' Star Diagonal 99% Reflectivity (see Part No. 0112165(CF))FEATURESthree lens air-spaced ED-apochromatHoya FCD01-ED glasspolystrehl of above 0.9Tube-weight: 4,9kg Tube length (retracted dew-cap): 560mm Dew-cap diameter: 154mm Tube diameter: 104mmbackfocus: 165mm above 2'' adaptorSCOPE OF DELIVERYOptics with dovetail plate and finder slot2'' Star Diagonal 99% reflectivityDust caps for front-lens and focuser

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

The longest focal length in the 52° Series with the longest eye relief, the 40mm is also the only 2.0-inch O.D. eyepiece in this series. Explore Scientific now has three 40mm eyepieces in its collection, the other two are the 40mm 62° Series, and the 40mm 68° Series. At this focal length, this eyepiece is generally reserved for deep sky observers who challenge themselves to observe near the faintest observable limit of their telescopes. The huge true field of view is perfect for deep sky objects like the Andromeda Galaxy, the Rosette Nebula, as well as large star clusters, and comets.Comfort, Quality, Value. The Explore Scientific 52° LER Series mid-range 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.SPECIFICATIONSLarge 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 DELIVERY52° EyepieceDust coversProtective bag

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 UHC filter uses a characteristic property of the so called emission nebulae. Those objects glow in special colours, their emission lines. Those emission lines are linked to chemical elements - in this case hydrogen at 486nm and 656nm, plus oxygen at 496nm and 501nm. The Explore Scientific UHC nebula filter blocks all other colours (and thereby nearly all of the artificial light) and only the emission line of the hydrogen and 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 Owl-nebula M97, the Veil-nebula NGC6992 or even the bright Dumbell-nebula M27 are not clearly visible. By using this filter you can see the nebulae and their 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 emission nebulaeblocks almost the entire artificial lightonly the two emission lines of hydrogen and oxygen passes the filterWHAT'S INCLUDED1x 1.25" UHC nebula filter