EXPLORE SCIENTIFIC ED APO 127mm f/7,5 FCD-100 Alu HEX

Triplet ED APO with 127mm aperture, FCD-100 objective lenses, lightweight aluminium tube and precision HEX focuser with gear reduction drive

  • Three lens apochromat with two air spaces
  • Aperture 127mm; focal length 952mm; f/7,5
  • HOYA FCD-100 glass for maximal color fidelity
  • High end 2,5" Hexafoc 10:1 DeLuxe Focuser
  • 2" Star Diagonal 99% included
  • Extension tubes for focusser (2pcs)
  • Handle features mounting place for cameras
  • 44mm universal dovetail with stainless steel protection included (Fits Super/Great Polaris, EQ5, LXD75, EXOS-II)
  • Dewshield slides onto tube for easy transport
  • Hybrid viewfinder shoe to accept different viewfinder holders

€2,199.00*

% €2,349.00* (6.39% saved)

Available, delivery time: 1-3 days

Product number: 0112134
GTIN/EAN: 4007922030944

Explore Scientific ED 127 CF – FCD01 compared to FCD-100

A product test: two models in direct comparison. Von J.S. Schlimmer

1. Introduction

2 Explore Scientific ED 127 CF Explore Scientific ED 127 CF

Figure 1: Explore Scientific ED 127 CF models under test

Since April 2016 I own the apochromatic one Refractor ED 127 CF, Model FCD01 by Explore Scientific and I use it for moon and planetary observation as well as for the photography of extended nebulas, open star clusters and galaxy clusters. In addition to the very good look, the possibility for photographic use with the help of a focal reducer, also the low weight of the telescope has influenced my purchase decision. Therefore, I could continue to use my old mount and invest the existing budget in optical accessories. The telescope is still transportable and thus suitable for mobile use outside the light-polluted cities. Explore Scientific is listed as a Bresser brand. The technical support I approached initially for some questions was very friendly, accommodating and very helpful.

2. Description

The ED 127 CF has a three-lens lens. Between the lenses there is an air gap. The tube is made of carbon fiber and processed to high quality. The ED 127 CF has a three-lens objective. There is an air gap between the lenses. The tube is made of carbon fiber and processed to high quality. Thanks to its low weight of only 7 kg, it can still be carried by a GP-DX or comparable mount.

Since November 2016, the improved FCD-100 model is on the market, which is advertised with high color purity and a perfect optical design. What’s the difference between these two models? To test this, Bresser has kindly provided me with an ED 127 FCD-100.

At first glance, both models resemble each other like twins, as my older model also has the 2.5-inch Hexafoc extract. In addition to the stable construction, it can also be rotated as a whole. In astrophotography this offers the advantage of preserving the focal position, even if the camera needs to be realigned for another object. The 1:10 reduction allows an exact focus. A scale applied on the pullout facilitates the presetting (Figure 2). In the case of visual observation the zenith mirror can of course be adjusted independently of the focuser.

Focal Reducer

Figure 2: Camera, 0.7x Focal Reducer and Hexafoc Extract

Both models have an aperture of 127 mm and a focal length of 952 mm. In lens labeling, the new model differs only in the additionally printed model designation. Only by closer inspection you can see that the tube of the new model FCD-100 is 15mm shorter. This is a great advantage, because my intrafocal area is very short on my own model. Therefore, in my model, orthoscopic eyepieces (e.g. measuring eyepieces) cannot be used if the extension is provided with an extension sleeve. With my wide-angle eyepieces the extension sleeve always comes to commitment.

3. Objective lenses

For observation I prefer to use wide-angle eyepieces. For almost 2 years my Nagler range has also been supplemented by eyepieces in the 82° series by Explore Scientific. For the telescope comparison the Explore Scientific 2-inch eyepiece with 24 mm focal length, as well as two Explore Scientific 1 ¼ inch eyepieces, with 8.8 and 4.7 mm focal length were used.

4. Explore Scientific 0.7 focal reducer and corrector

of 64 mm (2.5 inches). To connect to Canon cameras, a special T2 adapter must be used. The adapter ring is only 1 mm thick and therefore made of steel. He has a free opening of 36.7 mm.

5. Visual tests

Explore Scientific Okulare der 82° Serie

Figure 3: Explore Scientific 82 ° Series Eyepieces

In particular, moon and planets are suitable as test objects for the visual comparison, while in the deep sky range the Orion comes into question with its richness of detail. Open star clusters, on the other hand, offer a very good opportunity to assess the edge imaging at low magnifications.

For the tests, the objects should be as high as possible in the sky, where the influence of astronomical seeing is significantly lower. Because the planets only reached a height of 23° at the meridian passage at the time of the tests, they were out of the question for the tests. For better temperature adaptation, the telescopes were brought to the open air 1-2 hours before the tests.

 

Aldebaranbedeckung

At dusk on the 23rd of February In 2018, Aldebaran was covered by the moon. The picture above shows the moon a few seconds before covering on the bright Sky. The small image inside shows the entire image field during the covering. The picture below shows the moon for one hour at the end of the Aldebaran covering. ES 127 FCD-100 and Focal Reducer, Canon 1100D

a) The moon

With the 2-inch 24 mm eyepieces, the moon fits comfortably in the field of vision. While the FCD01 showed a light, yellow color fringe around the bright edge of the crescent, the image of the successor model FCD-100 was without any color aberrations. The higher the magnification the more details revealed on the lunar surface. The sight became really fascinating at 200x magnification with the 4.7 mm eyepiece. In the Apennine Mountains were already single, larger rock formations to recognize. In the south, on the edge of the Mare Nubium, the Long Wall was just visible, an approximately 100 km long embankment. The crater Thebit could be easily observed on one side of the long wall and Birt and the side crater Birt A on the other side. On closer inspection you could see further small craters such as e.g. Thebit D at the end of the long wall. Also Rima Birt, a groove that runs almost parallel to the Long Wall, but only as half long, was easy to see. Below are some pictures of the Aldebaran covering from 23rd February 2018. The beginning was still in the clear sky, so that Aldebaran was difficult to locate. At the exit one hour later the sky was already dark.

b) Open star cluster: Pleiades and NGC 1647

For the observation of the Pleiades also the 2-inch 24 mm eyepieces was used. With this eyepiece, the Pleiades are a breathtaking sight, because they fit completely into the field of view. In both telescopes, the stars were as fine as needle points and point-shaped to the edge. Visually, no color errors were noticeable. It was such a perfect sight.

NGC 1647 is a very loose open star cluster nearby 97 Tau. Because it is very extensive, it is best seen at low magnification. Approximately 20 stars with a brightness of 8 mag can be captured well with the 2-inch 24-mm eyepiece. Again, the sight is fantastic, as the entire field of view is sharply displayed.

c) Stars and binary stars

Intra- und extrafokale Beugungsscheibchen

AFigure 5: Intrafocal and extrafocal diffraction disks

What about the comparison at high magnifications? Inadequate color correction of refractors is shown by blue color fringes around bright stars. To test this, the choice fell on Bellatrix, the "warrior" in Orion. This star is 1.6 mag bright, bluish giant star of the spectral class B2. At moderate magnification with the 8.8 mm eyepiece (108x), neither the CD01 nor the successor FCD-100 showed any fringing. At high magnification with the 4.7 mm eyepiece (203x), diffraction rings around Bellatrix were clearly visible, but no fringing. However, at this magnification already the atmospheric dispersion was noticeable, as Bellatrix only reaches a height of 46 ° in the meridional passage. The atmospheric dispersion is shown by blue color in the upper area and red color in the lower area of the star. However, it is an atmospheric effect and not due to the telescope optics.

In the constellation Orion there are also numerous binary stars, which can be used to test the resolution. For example, 32 Ori (STF 728) could not be resolved at a distance of about 1.2 arcseconds. For 52 Ori (STF 795), which has a spacing of only 1.0 arcseconds, both components could be detected but not completely separated. The reason for this is in different contrast: the components of 32 Ori have a brightness difference of 1.3 magnitudes, while the components of 52 Ori are equally bright. The observation of Alnitak (STF 774), the eastern belt star of Orion was also interesting. With a distance of at least 4.7 arc seconds, this double star should be easy to separate, despite its brightness difference of 1.8 magnitudes. At 203x magnification Alnitak was also clearly to separate, however the B-component could only be seen at second glance in the diffraction rings. With the 8.8 mm eyepiece Alnitak was inseparable. Of course, with this type of observation, astronomical seeing plays a crucial role. Unfortunately, lunar observation was only possible with good astronomical seeing. At all other tests the astronomical seeing was not very good. In conclusion, the difference between the two models FCD01 and FCD-100 is hardly noticeable in visual observations.

6. Photographic tests

a) Diffraction slices in the primary focus

To get a better overview of the color difference between the two models, the defocused diffraction discs were first used recorded in the primary focus at 952 mm focal length (Figure 5). For this a QHY 5L II-C color CMOS camera was used. The images were taken at a distance of -2.2, -1.1, 0, +1.1 and + 2.2 mm from the focus. The light source was Bellatrix.

Overall, my model FCD01 showed slightly more color differences between the intra- and extra-focal diffraction slices. In the intrafocal area it appears slightly greenish, while in the extrafocal area it shines reddish. The successor model FCD-100 shows no color differences between the intra- and extra-focal diffraction disks.

Orionnebel

Figure 6: Orion Nebula 16 x 30 seconds, 800 ASA, ED127 CF FCD-100, 0.7 x Focal Reducer

a) Astrophotography with the Explore Scientific 0.7x focal reducer

Bellatrix und Beteigeuze

Figure 7: Bellatrix and Betelgeuse, 5x30 seconds, 800 ASA

Beteigeuze

Figure 8: Complete picture of Betelgeuse, the inlays show the Star illustrations in the corners on the lower left and upper right

The photos in this review were taken with a modified Canon EOS 1100D. It can also be used for the absorption of hydrogen regions due to the lack of red filter. For the recordings, the camera was connected directly to a laptop via a USB cable and operated exclusively via the Canon "long-distance shot" menu. The focus was set on the live image in 10x zoom mode. Exposure time and sensitivity were also controlled via the laptop. The pictures could be viewed directly after the picture was taken on the screen. The pictures were taken with an exposure time of 30 seconds at 800 ASA. To reduce noise, flat and dark images were also created.

With my FCD01 model, the sharpness can be easily adjusted by the color of the diffraction disk. As soon as the color becomes minimal, or changes from a slight green cast to reddish, the perfect focus is found. This method always worked well and led to quick results. In which Successor model FCD-100, this method could not be applied due to the color purity. Therefore it took some practice to find the right focus. A self-made focusing aid has proven to be helpful. The focusing aid consisted of a ring that was placed on the dew cap. Attached to the ring was a thin ridge that ran through the center, creating a one-dimensional diffraction pattern in the image. Based on the diffraction image was the adjustment of sharpness.

The focusing aid was removed again for photography and bright stars in Orion were once again chosen as test objects. Figure 7 shows Bellatrix (spectral type B2) and Betelgeuse (spectral type M2) taken with the FCD01 and the FCD-100. Exposing time was 5 × 30 seconds and corresponding flat pictures were taken. The different colors are shown very nice in both models. Due to the red sensitivity of the camera, a correspondingly large halo appears around Betelgeuse.

Für For deep sky shots of extended objects not only the color but also the marginal image is of interest. Figure 8 therefore shows the complete picture of Betelgeuse taken with the FCD-100. The inlays show the star pictures in two opposite corners. The 0.7x Focal Reducer levels the image over the entire APS-C format of the camera. Very red stars in the border area are no longer 100% displayed due to dispersion phenomena. The strength of this effect depends on the spectral type of the star and of course on the red sensitivity of the camera and can be observed only at full image resolution (here 4273 pixels x 2848 pixels).

On the basis of the flat images, the vignetting of the two telescopes could also be determined very easily. The vignetting is shown by the edge darkening of the image field. In both models, the brightness drops to around 77% of the center brightness in the outermost corners. This corresponds to about half an aperture. Figure 6 shows another shot of the Orion Nebula taken with the FCD-100. At the time of shooting, the sky was already lit by the half moon. The colors of the stars are rendered beautifully. There was no color correction during the image process, only the tonal values have been changed. In the predecessor model FCD01, the stars appear on deep sky shots usually with a slight green tint, which is easy to correct in subsequent image editing.

7. Conclusion

In all tests, the FCD-100 has shown no color errors, while the previous model FCD01 still has low color errors. With the improved look of the FCD-100, Explore Scientific / Bresser has reached the limits of color purity in imaging. Bei der Fotografie ist es beim FCD-100 schwieriger den exakten Fokus zu finden wie beim Vorgängermodell FCD01. Eine Fokussierhilfe und etwas Übung verhelfen aber auch hier zum gewünschten Ergebnis. In photography, the FCD-100 is harder to find the exact focus like the previous model FCD01. A focus aid and a little bit of practice help to achieve the desired result. The border image on both models is in conjunction with the Explore Scientific 0.7 x Focal Reducer APS-C format punctiform. The image field illumination is very uniform and shows only slight vignetting. The 2.5-inch Hexafoc extract is built mechanically very stable and can be rotated as a whole. This allows a camera to be arbitrarily aligned with the focus position almost preserved. Due to the 15 mm shorter tube on the FCD-100 compared to the FCD01, the intrafocal area of the hexafoc is significantly larger. This also means that orthoscopic Eyepieces (for example, measuring eyepieces) can be used without removing the extension sleeve. Overall, the Explore Scientific 127 FCD-100 is a fantastic 5-inch telescope that impresses visually and photographically. In addition, it is transportable with a weight of just under 7 kg and is also carried by a GP-DX or comparable mount.
Product information "EXPLORE SCIENTIFIC ED APO 127mm f/7,5 FCD-100 Alu HEX"
Highly corrected 127 mm air-spaced triplet apochromat (with three lenses) and aluminium tube and a 2.5'' high-precision HEXAFOC focuser. NEW: Now with hybrid viewfinder shoe to accept different viewfinder holders.

Apochromats are the ultimate choice in small to medium-sized telescopes: the combination of compactness, transportability, very high image contrast and sharpness together with the possibility to make excellent astrophotos cannot be bested. The advances in glass manufacturing during the last few years have made true apochromats available to more astronomy enthusiasts than ever before. The new Explore Scientific FCD-100 Alu Hex represents another major improvement in this field - the overall correction (colour and spherical) is setting new standards in this price class. The optical design shows a polystrehl value of 0.97 indicating a level of correction that is absolutely top of the line.

This excellent apochromat is a very versatile telescope: the fast f-ratio makes short exposure times possible. The high contrast and sharpness of the image provide breathtaking views of large objects like the North America nebula or the Andromeda Galaxy, as well as tack sharp planetary images. The telescope is lightweight and compact - the dew shield slides down the tube to minimize size for transportation. Revolutionary glass and precision manufacturing created a telescope that offers observing joy on the highest level. This does not only qualify this telescope as the ideal travel scope, it is also the perfect choice for fast observations and for astrophotography. The excellent 2,5'' HEXAFOC focuser with 10:1 reduction is perfect for this - the large inner diameter of 65 mm prevents vignetting by the focuser when the telescope is used for astrophotography with large sensors.

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 and 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 Glass 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))

SPECIFICATIONS
  • Aperture: 127 mm
  • Focal Length: 952 mm
  • Focal ratio: f/7.5
  • Design: Apochromat with three lenses, two air spaces and FCD-100 glass
  • Weight: 7.7 kg
  • Back focus: 150 mm above 2'' adaptor
  • Hybrid viewfinder shoe to accept different viewfinder holders

SCOPE OF DELIVERY
  • Optical tube with retractable dew-shield
  • 2.5'' HEX focuser with 1:10 gear reduction
  • 2'' Star Diagonal 99% reflectivity
  • Tube rings with dovetail plate and handle
  • Dust caps for front-lens and focuser
  • Hybrid viewfinder shoe
Colour: white
Field of application [Telescopes]: Deep Sky Observation, Deep Sky Photography, Lunar observation, Lunar photography, Planetary observation, Planetary photography
Focus Group [Telescopes]: Advanced Amateurs, Specialists and Research, Visual enthusiasts
Focusing system: 2.5" Hexafoc DeLuxe with 10:1
Material: Aluminium
Material front lens or corrector plate: HOYA FCD-100
Mount Type [Telescopes]: Optics without Mount
Optical design: Apochomatic Refractor
Product Family [Telescopes]: Refractor telescope
Type of coating: Enhanced Multilayer Desposition (EMD)

Accessories

EXPLORE SCIENTIFIC 3" 0.7x Reducer/corrector
The EXPLORE SCIENTIFIC 3" 0.7x Reducer/corrector, reduces a compatible telescope's focal length by a factor of 0.7x (for around f/8) and 0.8x (for around f/10) respectively. The reducer/corrector not only reduces the focal length but also flattens the field. Although originally developed for the Explore Scientific ED-APOs 127mm and 152mm, the reducer can be used with many systems - for example with the Explore Scientific ED-APOs 102mm and 165mm (please note, this will not work on the Explore Scientific 80mm ED Apo refractors though). With certain telescope focal lengths, a slight restriction of the correction at the edge of the image field can be expected when using full-frame sensors. This unit comes with 3" barrel adaptor for direct focuser thread M54x0.75 (the standard focuser thread of the Explore Scientific Essential series of ED Apos) and T2 camera adaptor. This reducer/corrector features a free aperture of 65mm, so that it can be used even with cameras that have a large sensor - if the telescope allows for this. Note: As previously mentioned, this Reducer/corrector comes with a screw on ring, which fits the standard focuser thread of the Explore Scientific Essential series of ED Apos. For telescopes which are equipped with the 2.5" HEX Focuser, the optional screw-on adapter part no: 0510366 is needed. Other telescopes, not in the Explore Scientific range, with standard 2" push-fit focusers will need the Explore Scientific 2" Adaptor for 3" Corrector - part no: 0510364 to get this reducer correctly fitted. SPECIFICATIONS Reduces the focal length by 0.7x at f/8 Flattens the field for astrophotography Developed for ED127 und ED152 APO telescopes Also fits Explore Scientific ED102 and ED165 telescopes - and others Free aperture: 65mm Inner thread for telescope adaption: M76x0.75mm Outer thread for camera adaption: M72x0.75mm 3" focuser barrel adaptor included Adaptor for Explore Scientific focuser M54x0.75mm included T2 camera adaptor M42x0.75mm included Diameter: 78.5mm; length: 100mm Length without adaptors: 52mm Weight without adaptors: 530g What's Included Reducer/Flattener 3" focuser barrel adaptor Adaptor for Focuser M54x0.75mm T2 camera adaptor M42x0.75mm Dust caps

€419.00*
EXPLORE SCIENTIFIC Hexafoc 2.5 adaptor for 3" 0.7x Corrector
This adaptor enables you to connect the 0510360 0.7x focal reducer/field flattner to telescopes that feature the 2.5" Hexafoc. The big inner diameter of the 2.5" Hexafoc is fully utilised with this adaptor to avoid vignetting.What's Included1x Hexafoc 2.5 adaptor for 3" 0.7x Corrector ring

€56.00*
EXPLORE SCIENTIFIC 2" Adaptor for 3" Corrector
Connects the 0510360 EXPLORE SCIENTIFIC 3" Corrector/Reducer to optical tubes with a 2" focuser.

€64.90*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 11mm (1,25")
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.

€179.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 14mm (1,25")
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.

€189.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 18mm (2")
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.

€239.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 24mm (2")
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.

€329.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 30mm (2")
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.

€369.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 4,7mm (1,25")
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.

€169.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 6,7mm (1,25")
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.

€169.00*
EXPLORE SCIENTIFIC 82° Ar Eyepiece 8.8mm (1.25")
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.

€179.00*
EXPLORE SCIENTIFIC 100° Ar Eyepiece 14mm (2")
These eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods. These ultra-wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye-relief counterparts helped reduce eye injury from recoil.Each 100° Series Argon-Purged Waterproof eyepiece is internally sealed and purged with inert, dry argon gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus. This also maximizes the life of the internal coatings.To make sure, every 100° eyepiece is tested by submerging them down to 1 meter of water for 30 minutes.All 100° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

€459.00*
EXPLORE SCIENTIFIC 100° Ar Eyepiece 20mm (2")
These eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods. These ultra-wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye-relief counterparts helped reduce eye injury from recoil. Each 100° Series Nitrogen-Purged Waterproof eyepiece is internally sealed and purged with inert, dry nitrogen gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus, and to maximize the life of the internal coatings. To make sure, every 100° eyepiece is tested by submerging them down to 1 meter of water for 30 minutes. All 100° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

€649.00*
%
EXPLORE SCIENTIFIC 100° Ar Eyepiece 25mm (2")
These eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods.These ultra-wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye-relief counterparts helped reduce eye injury from recoil.Each 100° Series Argon-Purged Waterproof eyepiece is internally sealed and purged with inert, dry argon gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus. This also maximizes the life of the internal coatings. To make sure, every 100° eyepiece is tested by submerging them down to 1 meter of water for 30 minutes.All 100° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

€486.00* €899.00* (45.94% saved)
EXPLORE SCIENTIFIC 100° Ar Eyepiece 30mm (3"/76,2mm)
These eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods.These ultra-wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye-relief counterparts helped reduce eye injury from recoil.Each 100° Series Argon-Purged Waterproof eyepiece is internally sealed and purged with inert, dry argon gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus. This also maximizes the life of the internal coatings. To make sure, every 100° eyepiece is tested by submerging them down to 1 meter of water for 30 minutes.All 100° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

€1,099.00*
EXPLORE SCIENTIFIC 100° Ar Eyepiece 5,5mm (2")
These eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods. These ultra-wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye-relief counterparts helped reduce eye injury from recoil.Each 100° Series Argon-Purged Waterproof eyepiece is internally sealed and purged with inert, dry argon gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus. This also maximizes the life of the internal coatings.To make sure, every 100° eyepiece is tested by submerging them down to 1 meter of water for 30 minutes. All 100° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

€369.00*
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EXPLORE SCIENTIFIC 100° Ar Eyepiece 9mm (2")
These eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods. These ultra-wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye-relief counterparts helped reduce eye injury from recoil.Each 100° Series Argon-Purged Waterproof eyepiece is internally sealed and purged with inert, dry argon gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus. This also maximizes the life of the internal coatings.To make sure, every 100° eyepiece is tested by submerging them down to 1 meter of water for 30 minutes.All 100° Series eyepieces are fully multi-coated and edge-blackened to produce maximum contrast.

€231.00* €369.00* (37.4% saved)
Explore Scientific 92° LER Eyepiece 12mm
If an observing session is a relaxing and joyful experience is heavily dependend on the choice of eyepieces. People wearing glasses very often have the problem to see the entire field of view when they are using eyepieces with large apparent fields. This problem is now history. The new 92°- LER eyepieces by EXPLORE SCIENTIFIC do not only offer excellent image sharpness and high resolution and contrast over the enourmous full field of view - you can see that full field without problems even with glasses on. Fatigue due to tense head positioning and strained viewing simply does not happen because of the excellent viewing comfort these eyepieces provide even to observers wearing glasses. Enjoy the unique combination of excellent image sharpness out to the edge of the field even for fast optics, superior contrast and unmatched viewing comfort. Eyepieces with perfect combinations of various modern glass substrates and highest standards in manufacturing, quality control and service are a tradition at EXPLORE SCIENTIFIC Tradition - the outstanding resolution and sharpness to the very edge equal that of our eyepieces of the 100° line.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 patentet EMD-coating teams up together with internal baffles to produce high contrast images and to prevent 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. FEATURESLarge eye distance and great image sharpness Excellent viewing position for people with glasses Excellent field sharpness even with fast optics Patented EMD"-coating to maximize contrast Blackened lens edges to avoid reflexes Argon-purging prevents internal fogging, the sealing facilitates cleaning Stainless steel barrel with conical security cutoff Gift box with magnetic lock - additional soft pouch for easy transport in the field SCOPE OF DELIVERY Eyepiece Box Pouch

€549.00*
EXPLORE SCIENTIFIC 92° LER Eyepiece 17mm
If a observing session is a relaxing and joyful experience is heavily dependend on the choice of eyepieces. People wearing glasses very often have the problem to see the entire field of view when they are using eyepieces with large apparent fields. This problem is now history. The new 92°- LER eyepieces by Explore Scientific do not only offer excellent image sharpness and high resolution and contrast over the enourmous full field of view - you can see that full field without problems even with glasses on. Fatigue due to tense head positioning and strained viewing simply does not happen because of the excellent viewing comfort these eyepieces provide even to observers wearing glasses. Enjoy the unique combination of excellent image sharpness out to the edge of the field even for fast optics, superior contrast and unmatched viewing comfort. Eyepieces with perfect combinations of various modern glass substrates and highest standards in manufacturing, quality control and service are a tradition at Explore Scientific Tradition - the outstanding resolution and sharpness to the very edge equal that of our eyepieces of the 100° line.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 patentet EMD"-coating teams up together with internal baffles to produce high contrast images and to prevent 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.

€549.00*
EXPLORE SCIENTIFIC 2" UHC 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 system enormously. Depending on the type of the celestial object, it is possible to dramatically increase the contrast by blocking annoying artificial light. The EXPLORE SCIENTIFIC UHC filter "zeros in" on the wavelengths of 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 colour wavelengths (and thereby nearly all of 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 invisible from, without filters. In suburban skies, for example the Owl-nebula M97, the Veil-nebula NGC 6992 or even the bright Dumbell-nebula M27 are not clearly visible. Using this filter allows you to see nebulae and their structures in much finer detail. A must for every visual observer. The Explore Scientific nebula filters come with a individual test certificate - your guarantee to receive a premium filter.

€89.00*
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EXPLORE SCIENTIFIC 2" Variable Polarizing 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

€57.00* €79.00* (27.85% saved)
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EXPLORE SCIENTIFIC Dark-Sky Filter 77mm Slim
Universal Dark-Sky Filter with 77mm thread for photo lens. Contrast enhancing filter for Aurora- and Deep-Sky imaging. Especially during Aurora imaging the most important wavelength of 550nm (green) and 630nm (red) this filter let pass by 90%. In comparrision to CLS filters, the Explore Scientific Dark-Sky Filter is blocking also the yellow Sodium (Na) wave at 590nm which elliminates Sodium-lamp street illumination from your picture. This is very useful because the yellow light is always a partially mix of green and red light. Removing the yellow wave-length with any image processing software will always damping also the green and red coloring. For Aurory imaging this is of course not wanted. At these days of increasing light pollution, the Explore Scientific Dark-Sky Filter is absolutely recommended in order to take pictures also from urban conditions. Finally the slim housing design enables its use also with wide-field photo lens and doesn´t cause any vignetting. Pictures at night taken by Bernd Pröschold - www.sternstunden.netTest report:  http://www.sternstunden.net/filter-testing.html  FEATURES Deep Sky Filter Contrast enhancer for Aurora- and Deep-Sky imaging Wide field imaging of the milky-way, time lapse and landscape Lightpollution damping filter Ellimintates the yellow light which can´t be done by any imaging processing software Black anodized filter housing 77mm filter thgread for foto lens flat design of only 4mm height (slim) - no vignetting Ideal also for wide field foto lens Made from optical glass with Neodymoxid SCOPE OF DELIVERY Deep Sky Filter 77mm Dust protection case

€79.00* €155.00* (49.03% saved)
EXPLORE SCIENTIFIC 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 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

€119.00*
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EXPLORE SCIENTIFIC 2" 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 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.

€75.00* €121.00* (38.02% saved)
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EXPLORE SCIENTIFIC 2" Grey- Moonfillter ND-09
The neutral density filter transmits light uniformly across the entire visual spectrum. It serves as an excellent filter to reduce glare and irradiation when observing the Moon with any telescope 4"(10.2cm) and larger. The ND96 filter may also be employed in the splitting of close double stars where one of the binary pair significantly exceeds the other in brightness. Color Filter #ND96 Moon Filter (0.9 density; 13% transmission)

€24.00* €48.00* (50% saved)
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EXPLORE SCIENTIFIC 2" CLS 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

€57.00* €83.00* (31.33% saved)
EXPLORE SCIENTIFIC 1.25" Variable Polarizing Filter
Universally usable variable polarizing filter with a  1.25" 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 1.25" 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 housing1.25" filter thread on both sidesSCOPE OF DELIVERYpolarizing filterprotective box

€59.00*
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EXPLORE SCIENTIFIC 1.25" Filter Grey ND0.9
The neutral density filter transmits light uniformly across the entire visual spectrum. It serves as an excellent filter to reduce glare and irradiation when observing the Moon with any telescope 4"(10.2cm) and larger. The ND96 filter may also be employed in the splitting of close double stars where one of the binary pair significantly exceeds the other in brightness. Very flat design, with only 5.0mm light path. FEATURESreduces brightness for a higher contrastideal for observing the mooncan be combined with other colour filtersvery flat design, with only 5.0mm light path SCOPE OF DELIVERY 1x Color Filter #ND96 Moon Filter (0.9 density; 13% transmission)

€18.00* €25.00* (28% saved)