EXPLORE SCIENTIFIC 1.25" O-III Nebula Filter

Explore Scientific 82° Series™ extreme wide field eyepieces are optimized to produce high contrast, high resolution, and superior flat field characteristics. The visual effect of these eyepieces with their long eye-relief and their 82° apparent field is truly a full-immersion experience. Your eye is relaxed, allowing you to easily use the "averted vision" technique to study faint details across a huge field-of-view. The 82° Series eyepieces come with a twist-up rubber eye-guard that raise to the desired height for the comfort of the observer, and as experienced astronomers know, eye comfort is critical when trying to observe at the visual limits of the telescope. To keep internal reflections to a minimum, all internal surfaces of the eyepiece barrel are flat black, as well as the edges of the lenses themselves to minimize the scattering of light within the lenses themselves. All 82° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

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 EXPLORE SCIENTIFIC 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 CLS filter

L-eNhance Filter for deep sky nebula photography from the cityThe relentless spread or urbanization and its associated light pollution have become a growing problem for all amateur astro photographers. The current solutions to the problem can be expensive and might include the purchase of a monochrome camera, several types of narrowband filters and a filter wheel. Especially with inexpensive newtonian telescopes, double-lens ED refractors or even achromats, the L-eNhance filters open up completely new possibilities for the capture of high-class astronomical images even out of the light polluted city. CMOS cameras can deliver images like monochrome cameras. This new generation of filters makes it possible to take amazing astrophotos directly from the light-polluted city with all its artificial light sources. The narrow bandpass for the wavelengths of O-III, H-Beta and H-Alpha and the almost complete attenuation of the interfering light sources of these new filters make this an ideal solution. L-eNhance Description  L-eNhance provides an economical and practical solution for amateurs. It is a tri-band pass filter which has been designed for DSLR (digital SLR), color CMOS and monochrome CCD cameras. The convenience and cost-effectiveness of this filter allows amateurs to take a rich selection of astronomical images, even in bright, heavily light-polluted areas. We believe the design of our L-eNhance filter is a technical innovation among filters. It effectively isolates the H-Alpha, H-Beta, and Oxygen III nebula emission lines and achieves a maximum transmission of up to 90%. The performance of this filter delivers images that superbly control the impact from light polluted skies.  Main Use and PerformanceThis new generation of filters makes it possible to take amazing astrophotos directly from the light-polluted city with all its artificial light sources. The narrow bandpass for the wavelengths of O-III, H-Beta and H-Alpha and the almost complete attenuation of the interfering light sources do not require very large or extremely expensive telescopes. No, especially with inexpensive newtonian telescopes, double-lens ED refractors or even achromats, these filters open up completely new possibilities for high-class astronomical images. Furthermore, with the help of these filters, CMOS colour cameras can deliver an image quality that comes close to CCD monochrome cameras. WARNING: These nebula filters are not designed for sun observation. DO NOT LOOK AT THE SUN WITH THIS FILTER. You will go BLIND if you ignore this warning. Coating technology L-eNhance has a multiple anti-reflective coating on the optical substrate. The L-eNhance filter uses a precision coating based on ion deposition coating technology. This ensures durability and scratch resistance as well as stability on the CWL (central wavelength), which is not affected by temperature changes. Absolute precision and homogeneity of the coatings as well as maximum values for transmission in the passband and optical density in the off-band range are guaranteed for all filters. FEATURES Professional photographic filter for astronomy Improves deep sky emission nebula photography Best choice for enhanced light pollution suppression For taking pictures also from highly light polluted areas Tri-band filter with high transmission for O-III, H-Beta and H-Alpha linesDoes not require very large or extremely expensive telescopesExcellent results also with inexpensive newtonian telescopes, double-lens ED refractors or even achromatsCMOS colour cameras can deliver an image quality that comes close to CCD monochrome cameras Balanced colour for a natural image Filter diameter: 1.25 inch / 31.7mm Connecting thread: M28,5 x 0,6mm (Eyepiece thread 1.25 inch)Selected optical glass material Spectrum: 300-1000nm Off-Band Blocking: > 99% Surface Quality: 60/40 (Refer to MIL-O-13830) Fine-optically polished to ensure accurate 1/4 wavefront and highest parallelism over the both surfacesHigh transmission at major nebula emission lines (i.e. H-alpha 656nm, OIII 496nm&500nm and H-beta 486nm). SCOPE OF DELIVERY L-eNhance filter (1pc) Dust protection box (1pc)

Fast 90 mm high-performance astrograph for demanding astrophotographers and observers with 5 lens elements in 5 groups. Due to the complex optical structure with five lens groups and five elements (quintuplet), including two SD (Super ED) lenses and an ED lens (Extra-low Dispersion) , a virtually aberration-free optical system was created. This revolutionary astrograph is compatible with a full-frame digital DSLR or an even larger 44x33 mm camera. The 90 mm astrograph with fast aperture ratio delivers exceptionally sharp, high-contrast and small point stars from the centre to the corners of the field of view. In addition, it is also ideal for visual observation with a very large field of view but also for planetary observation with high magnification. The VSD90ss is designed so that there is a "long peak range" in the adjustment accuracy of the sharpness, so that photographers can always achieve satisfactory results in astrophotography. Even if the focus is not quite precise, round and sharp stars are still shown throughout the entire image field. Illumination without vignetting In most cases, an astrograph also produces optical vignetting (a gradual decrease in light rays towards the edge of the image) This is mainly caused by rear lenses being shaded by the front lenses. Because of this darkening, it is relatively normal for the photographer to have to further edit the image after taking the picture and also have to do some additional so-called flats before taking the picture. To solve this problem, the VSD90ss uses wide aperture lenses in the rear elements, securing over 90 % of the light volume at the edge of the 60 mm image circle. Since the light intensity is uniform throughout the entire image field of the VSD90ss, there is no need for complex technology to prevent edge darkening. The VSD90ss is coated with the most modern coatings of extremely high reflectivity. These coatings have been specifically developed to optimize the properties of each individual lens element without degrading contrast and light intensity across multiple lenses. Numerous gradations of light bring beautiful point-like stars into the image field The low optical vignetting ensures sufficient illumination and thus eliminates the asymmetric flare caused by bright, diffraction-limited stars. It prevents stars at the edge of the 60 mm image circle from exhibiting deformations such as comets, astigmatism or coma. Since the illumination of the image field is relatively similar from the center to the edge of the image, you can expect excellent star imaging. Please note: *Depending on the recording system used, mechanical vignetting can still occur due to the camera body or incorrect adapters. 96.7％ Strehl for impressive visual observations The VSD90ss offers a flattened large field of view with a low magnification wide angle eyepiece. Even with a high-quality wide-field eyepiece with a large field of view, you can get sharp images of stars in the entire field of view when visually observing! In the centre of the field of view, a Strehl intensity of an impressive 96.7% is achieved at visible wavelengths. This Strehl ratio exceeds that of the SD81SII apochromat at 95.7%, which is known for its excellent optical properties, and this also works excellently when observing the moon and planets at high magnification. The versatile large and stable focuser The VSD90ss has a large focuser with a diameter of 87.5 mm to make optimal use of the large illumination field of 60 mm. With the large extension that is compatible with many accessories, it is perfect for astrophotography up to large format or 35 mm full frame DSLR cameras. Thanks to its precise manufacturing, it is also suitable for very heavy cameras without tipping. The precision locking lever of the eyepiece extension The focuser's extension tube has a locking lever that holds the extension tube firmly in position even when using heavy cameras such as large format cameras or CCD cameras with a large sensor. The locking lever clamps the rack gear to the extension barrel so that the viewing angle or focus on your camera does not shift. Compatible with motor driven focusers An optional two-speed motor focuser (not included) is available for the VSD90ss to provide sensitive focusing. An EAF (Electronic Automatic Focuser) from ZWO or equivalent can also be retrofitted. Optional VSD Reducer for even faster results The tried and tested optional VSD reducer, which was also used on the predecessor, the VSD 100, is also compatible with the VSD90ss. The photographer gets even faster results in astrophotography with an aperture ratio of 1:3.9. CHARACTERISTICS 90 mm aperture, 495 mm focal length (F5.5) Needle-fine stars up to the image field edge in 44x33 mm format 5 lens elements in 5 groups Image illumination up to 60 mm Resolution power: 1.29 Limit size: 11.5 Light gathering capacity: 165x Illumination: 60 mm Dimensions: 115 mm diameter x 600 mm length (476 mm length for storage) Weight: 4.3 kg Connections/Thread: Size thread/84 mm (pitch 1 mm), 60 mm (pitch 1.0 mm), 42 mm for T-ring push fit / 60.2 mm, 50.8 mm and 31.7 mm Solar observation: separately available solar projection approach B Optional VSD100 reducer compatible (opening ratio F: 3.9) SCOPE OF DELIVERY VSD90ss high performance astrograph