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HF2-BT81S-A Complete binocular telescope set

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FAQ - Frequently Asked Questions

The first number indicates the magnification (here: 8x). The second number describes the objective lens diameter in millimeters (here: 42 mm).
ED glass (Extra Low Dispersion) reduces chromatic aberration (color fringing) and ensures brilliant, true-color images.

  • BK-7 (borosilicate glass): Standard, good imaging performance
  • BaK-4 (barium crown glass): Higher quality, rounder exit pupils, brighter and higher-contrast image

Help & Service for your product

Here you will find quick help, answers to frequently asked questions, and the direct path to support.

Service Portal

Please use our product help search to find answers to your questions. Simply enter the item number or EAN and open the appropriate help page directly.

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Guides & Tips

FAQ - Frequently Asked Questions

That is normal. Finder scopes are only used to make objects easy to locate. The image orientation does not matter for observation.

  • Alt-azimuth: easy to use, moves horizontally and vertically
  • Equatorial: enables precise tracking of objects with only one axis – ideal for high magnifications and astrophotography

  • Moon: from 30 mm
  • Planets: from 100 mm
  • Deep sky: from 150 mm
Are you a member of an astronomy club? Find out here what your benefits are.
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Product and safety instructions


Manufacturer: 
Bresser GmbH, Gutenbergstraße 2, 46414 Rhede

Contact: 
www.bresser.de


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Accessories

Vixen SLV 50° Eyepiece 25mm (1.25'')
Tn.

Available

£133.00*
Vixen SLV 50° Eyepiece 15mm (1.25'')

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Vixen SLV 50° Eyepiece 12mm (1.25'')

Pre-order

£133.00*
Vixen SLV 50° Eyepiece 10mm (1.25'')

Available

£133.00*
Vixen rigid Accessory Tray for HAL130 and Porta II Tripods
 offers practical storage space for eyepieces and various accessories.

Available

£27.00*
Vixen SG-L02 Headlamp red-light white-light
The perfect LED head torch for nighttime observations! Adjusting your eyes to the dark surroundings is very important when making astronomical observations. In dark areas, it is very difficult to use astronomical equipment without a suitable light. With normal lights, however, the light intensity is more important than protecting your eyes against bright light. Using these lights at night makes your pupils contract, which can make it difficult for your eyes to readjust to the darkness. The SG-L01, our first astronomy LED lamp, featured a built-in red LED that provided a solution to this problem. However, the red light did not offer optimal visibility. On our new astronomy LED light, the SG-L02, the LED lights produce warm light to improve visibility. They also ensure that your eyes stay adapted to the dark. The LEDs do not emit light in the sensitive range of 555 nm. The brightness of the white light can be adjusted between 3 and 42 lumen, while the red light can be adjusted between 0.28 and 7.62 lumen. FEATURES Dimmable red light ensures that your eyes stay adapted to the dark Built-in rechargeable battery, charges via USB Waterproof design LED colour can be switched from red to white 0.28 to 7.62 lumen for red light 3 to 42 lumen for white light Dimensions: 41 mm x 33 mm x 30 mm Weight: 29 g DELIVERY CONTENT SG-L02 head torch Strap (size S) Strap (size L) Pocket clip Cable for charging the battery (USB-A plug to USB Micro-B plug)

Available

£65.00*
Vixen XY Red Dot Finder Scope II
Red dot finder for astronomical telescopes. This finder scope provides an easy way to align your telescope with objects in the night sky.The brightness of the dot can be adjusted via a dial.Designed for the Vixen viewfinder shoe FEATURES Weight: 185 g / 6.53 oz Battery: CR2032 Magnification: 1x 1/4" screw hole, adjustable red pointDELIVERY CONTENTLED red dot finderCR2032 battery

Available

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Vixen Viewfinder 7x50, with illuminated reticule
The Vixen Viewfinder 7x50, with illuminated reticule is an exceptionally high quality optical finder scope, featuring 50 mm Achromatic objective. The internal crosshairs are accurately inscribed and can be illuminated with a battery-powered LED attachment, which can be varied in brightness to the user's requirements. This finder gives a field of view of 7.2° in the night sky. Please note: this finder does not come with a bracket, but will fit numerous standard finder brackets - the X000288 Vixen S 50 mm finder scope short holder, or the X000073 Vixen XY finder scope long holder are particularly recommended. FEATURES Finder with 50 mm achromatic optics Field of view: 7.2° Battery: CR2032 Dimensions: 218x53 mm Weight: 0.375 kg WHAT'S INCLUDED: Viewfinder 7x50, with illuminated reticule

Available

£145.00*
Vixen XY finder scope holder, long with spring
Finder holder with spring

Available

£65.00*
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BRESSER RC Weather Station Neomeo H
Colourful, clear, and precise – the BRESSER RC Weather Station Neomeo H provides all the essential meteorological data for the day. In addition to outdoor temperature and humidity, information about the indoor climate is also displayed on the attractive screen. Useful features like temperature and frost alarms, max/min value display, automatic time and date setting, and an integrated alarm clock make this weather station exceptionally functional. Weatherproof on the go with forecast and measurement data Wondering if you need an umbrella or sunglasses today? The graphical weather forecast of the BRESSER Neomeo H Wireless Weather Station will help you decide. It also shows you the current outdoor temperature and humidity right outside your door. The temperature alarm for the outdoor sensor notifies you when your personal thresholds are reached. Additionally, the frost alarm will blink on the screen when the outdoor temperature is between -1 and +2.9 °C. Keep an eye on the indoor climate with the weather station Whether at the office or at home, it's important to have the indoor climate just right. This means keeping track of the indoor temperature and humidity. The colourful weather station not only provides specific measurements but also displays a helpful indoor climate comfort indicator. The 24-hour max/min temperature and humidity readings can also help in preventing mould. Weather station with outdoor sensor for precise weather data The range of the thermo-hygro outdoor sensor is impressive at up to 80 metres – enough to find the best spot for accurate measurements. The current data can be read directly on the LCD display at the sensor. Thanks to the IP44 protection class, the sensor is well-protected against the elements – a true professional among sensors. Get your BRESSER RC Weather Station Neomeo H and enjoy precise indoor climate and weather updates!  BASE STATION FEATURES Weather station with attractive colour display Indoor temperature and humidity (°C/°F) Displays outdoor temperature and humidity (°C/°F) Graphical weather forecast Indoor climate comfort indicator Temperature alarm for outdoor sensor Frost warning on the display Displays 24-hour max/min temperature and humidity Automatic DCF time and date setting, manual setting possible Integrated alarm clock with snooze function Power supply: mains adapter (included) and 3x AAA backup batteries (not included) PLEASE NOTE: This device receives the DCF time signal (Central European Time). However, you can easily adjust the time display to different time zones using the manual time setting. FEATURES SENSOR Measures temperature and humidity Clear LCD display Range: up to 80 metres IP protection class: IP44 Dimensions: 71 x 65 x 23 mm / Weight: 44 g Battery-operated: 2x AAA batteries (not included) SCOPE OF DELIVERY Base station 1x wireless sensor Mains adapter Instruction manual

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Vixen SLV 50° Eyepiece 10mm (1.25'')

Available

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EXPLORE SCIENTIFIC BT-100 SF Giant Binoculars with 62° LER Eyepieces 20mm
Giant binoculars for observing the starry sky, nature and landscape. Observe the beauty of the starry sky at night and distant objects in nature during the day. Globular star clusters, glowing gas nebulae, the moon with its craters and even planets can be observed wonderfully on a clear night. But also all other distant things in nature and landscape, even ships and airplanes can be seen in detail. With the all-round binoculars of the EXPLORE SCIENTIFIC BT series, you can get up very close. Thanks to the large, light-gathering lenses and the professional coatings on all lens surfaces, these binoculars produce bright and brilliant images even at night and at twilight, providing a special viewing pleasure. The comfortable 45 degree viewing angle allows fatigue-free use even when the binoculars are tilted strongly.  Large binoculars can also be called a double refractor telescope One complete lens telescope with the full light gathering power is available per eye. Experience a whole new dimension of observing. Objects are reproduced almost vividly in these binoculars and observing with both eyes is basically very relaxed. Last but not least, this comfortable way of observation increases the recognition of the finest details and effectively prevents rapid eye fatigue. Extremely robust binoculars with magnesium housing, sealed and filled with nitrogen  The BT series binoculars are designed for tough outdoor use. The IPX6 sealed and nitrogen-filled design effectively prevents fogging of the internal optics even under difficult weather conditions. The very light magnesium housing saves weight and makes it easy to handle. Two EXPLORE SCIENTIFIC 20mm eyepieces of the 62 degree LER series already included. EXPLORE SCIENTIFIC is an established manufacturer of extremely high-quality eyepieces in the astronomy scene. An optical system is only as good as its weakest component. Therefore we have decided to deliver these giant binoculars with a pair of quality eyepieces of the 62 degree LER series. With an apparent field of view of 62 degrees and a focal length of 20mm, the BT-100 binoculars produce a 28x magnification. Thus these wide angle eyepieces offer a very good overview (field of view 2,3 degree) at moderate magnification. The large interpupillary distance of these LER (long eye relief) eyepieces of 15mm and soft silicone eyecups, which can be turned inside out, also guarantee a comfortable and relaxed view. For astronomy, a flat and sharp image field is advantageous and offers a particularly impressive viewing experience even during the day. Due to the waterproof design and the argon filling, these eyepieces are absolutely durable and easy to clean. Interchangeable eyepieces with 1.25 inch / 31.7mm plug-in diameter Adjust the magnification and field of view to your individual needs and choose from a wide range of available eyepieces. All eyepiece types with a plug-in diameter of 1.25 inch / 31.7mm can be used with the binoculars of the BT series. Especially recommended are EXPLORE SCIENTIFIC eyepieces of the 62 and 82 degree series with focal lengths from 8 to 26mm (see item No. 02188xx and 02196xx). The magnification can be varied from 21x to 70x (focal length binoculars : focal length eyepiece = magnification). The eyepieces are held in the binoculars by a precise brass compression ring clamp and guarantee a tilt free position.  Use of color and nebula filters for astronomical observations Increase the contrast and visibility of objects and details by screwing the corresponding filters directly into the thread of the eyepiece sleeves. The use of color and nebula filters must of course always be done in pairs. Suitable are all EXPLORE SCIENTIFIC screw filters with 1.25inch / 31.7mm diameter (see item No. 03102xx)  Comfortable 45 degree view and helical single focus The 45-degree viewing angle allows a relaxed observation position even when the binoculars are tilted strongly. Also the individual interpupillary distance can be adjusted in a range from 54 to 76mm. With the fine helical individual focusing, precise focusing is achieved effortlessly. Extendable dew caps The integrated dew caps can be removed in high humidity and cold conditions. This avoids fogging of the outer objective lenses and effectively shields additional control light coming in from the side. Integrated carrying handle A metal carrying handle located at the center of gravity facilitates transport and ensures a secure hold during tripod assembly. Suitable tripods and tripod connectionWhen using these large binoculars, a sturdy photo tripod with an appropriate load capacity is highly recommended. The connection is made via two 1/4 inch or one 3/8 inch threaded holes (standard photo tripod thread) in the tripod adapter of the binoculars. The ideal solution is to use the optional availlable EXPLORE SCIENTIFIC U-Mount with field tripod (item No. 0114300). This is specially designed for the large binoculars of the BT series and carries these devices absolutely safely. The excellent mechanism with adjustable friction in both axes allows easy moving and tracking. The binocular position is kept stable depending on the adjusted friction intensity. Vibrations are reduced to a minimum by the massive construction of the U-Mount and the large stainless steel tripod. Even at high magnification there are no vibrations and the finest details can be observed.FEATURES Large binoculars for observing the starry sky, nature and landscape Observe globular star clusters, glowing gas nebulae, the moon with its craters and even planets Also wild animals, ships and airplanes can be seen in detail Highly light gathering lenses produce a bright and high-contrast image All-round binoculars, but especially suitable in twilight and at night The comfortable 45 degree viewing angle allows fatigue-free use One complete lens telescope with the full light gathering power is available per eye Extremely robust binoculars with magnesium housing, sealed and filled with nitrogen Two EXPLORE SCIENTIFIC 20mm eyepieces of the 62 degree LER series already included 28x magnification and an apparent field of view of 62 degrees, true visible field of 2,3 degreesLarge interpupillary distance of 15mm to the eyepiece lens for comfortable viewing Eyepieces interchangeable and with standardized plug-in diameter of 1.25 inch / 31.7mm The magnification can be adjusted with optional eyepieces from 21x to 70x Precise brass eyepiece compression ring clamps for tilt-free fitColor and nebula filters can be used for astronomical observations Extendable dew caps prevent fogging of the outer objective lenses and stray light Integrated carrying handle facilitates transport and mounting on the tripod Tripod connection via two 1/4 inch or one 3/8 inch threaded holes (standard photo tripod thread) Tripod recommendation: EXPLORE SCIENTIFIC U-mount with field tripod (Art.No. 0114300) Objective type: Air spaced achromatic lens (2 elements/ 1 group) Coating: full multilayer coating on all optical surfaces Aperture, focal length and aperture ratio: 100mm / 550mm / F=5.5 Sealed to IPX6 standard and nitrogen filled: yes / yes Close focus distance: 25 meters Eyepiece mount diameter: 1.25'' / 31.7mm Adjustable interpupillary distance: 54 to 76 mm Helical single focus: yes BAK-4 prism system for a bright and high-contrast imageDimensions and weight of binoculars: 520 x 270 x 155mm, 6.8kg Housing color of binoculars:  white SCOPE OF DELIVERY Giant binoculars with carrying handle (without tripod)Eyepieces ES 20mm 62 degrees LER Series (2pcs)Precisely fitting foam insert for transport Dust covers for objectives and eyepiece sockets Instruction manual

Available

£1,359.00* £1,699.00* (20.01% saved)
BRESSER BinoViewer Deluxe 1.25''
You see better with two eyesThe BRESSER BinoViewer Deluxe makes it possible to observe astronomical objects in a relaxed way with both eyes and with considerably more detail than using one eye. The images created of the moon, planets and globular clusters are particularly impressive. But also with deep-sky objects such as the Orion Nebula the detection of details is much easier. At the same time this binoviewer is very easy to handle. Thanks to the newly patented optical system you can get into focus with any telescope. All you need is a pair of identical eyepieces to enjoy this dramatic and immersive viewing experience.How to use the BinoViewer? Since the BRESSER BinoViewer Deluxe does not require an additional light path (back focus), it can be used with any telescope - including Newtonians and short focus refracting telescopes, which traditionally suffered when using standard binoviewers. No light path corrector or similar accessory is necessary. If a standard 1.25'' eyepiece can be focused, the binoviewer will also work. The eyepiece focal length and field of view size of the eyepieces used are fully retained. As with binoculars one eyepiece is focused first using the telescope focuser. Then the second eyepiece can be brought into focus using the helical focuser on the binoviewer. The required interpupillary distance is then elegantly adjusted to a range of 58–74mm with the help of a linear sliding mechanism, with graduated marker, to help you find your ideal interocular setting quickly.  Self-centring helical eyepiece grips, rather than side-mounted thumbscrew eyepiece retainers are used, decreasing the chance of offsetting collimation of both eyepiece to each other.  The fact that this design of binoviewer uses a well-engineered linear slide mechanism to adjust interpupillary distance, rather than a cheaper-to-produce traditional hinged design also helps retention of collimation.Which objects can be observed with this accessory?Actually, all objects that were previously observed with the telescope in question, but only monocularly with one eye. Because there is no magnification factor at the binoviewer, even low magnifications can be achieved. This makes not only the moon, planets and globular clusters, but also the brighter deep-sky objects very interesting observation targets. The use of two eyes leads to a more relaxed view than using one eye alone.  Although true depth of field viewing at infinity is a little beyond most telescopes and binoviewers, users will note how the human brain attempts to impose depth of field ("3d-like") effects on stereo views through binoviewers.  The biggest difference that most observers comment upon when comparing views through binoviewers like these, as opposed to single monocular eyepiece views, is the extra detail that can be seen in most observable targets.  Relaxed viewing and extra detail in objects are the two main benefits of binoviewing, which the BRESSER Bino Viewer Deluxe 1.25'' delivers in abundance.Also ideal as an accessory for solar telescopesA very special application is the use of the BRESSER BinoViewer Deluxe in combination with all solar telescopes. The spherical shape of the sun with all its surface details is shown very impressively.  The depth of field effects of seeing filaments silhouetted against the solar surface are particularly enjoyable to observe.Important note: Do not use the BRESSER Binoviwer Deluxe without a suitable solar telescope or a safe solar filter in front of the telescopes objective lens . Otherwise, there is an acute risk of going blind.High-quality mechanics and materialsThe entire BRESSER BinoViewer Deluxe is made of high-quality materials. Except for the outer plastic covers all components are made of anodised aluminium. Particularly remarkable are the low-backlash sliding mechanism for adjusting the interpupillary distance and the precise rotary clamping of both eyepiece adapters. The wide clamping surface holds the eyepieces in place securely and also centres them automatically on the optical axis. The one-sided dioptric adjustment has a backlash-free helical drive and enables the finest corrections. For safe transport a high-quality hard-shell transport case is included in the scope of delivery.Which eyepieces can be used?All eyepieces with a 1.25'' barrel and a field stop of up to 22mm. Depending on the interpupillary distance the outer diameter of the eyepiece housing should not exceed a value of approximately 50 mm.Filter thread 1.25'' availableNo 2nd filter sets are necessary to operate the BRESSER Binocular Approach Deluxe. The desired colour or nebula filter can be screwed directly into the 1.25'' nosepiece. in this configuration, when changing the eyepieces to affect a change in magnification, no swapping of filters is necessary.  Unique mirror-lens system with Ohara (Japan) lanthanum glass material The BRESSER Binocular Viewer Deluxe is equipped with a unique mirror-lens system. This has the advantage of higher light transmission and less color aberration. The resulting image is simply brighter and sharper. To achieve this the exclusive Ohara (Japan) lanthanum glass material has been used and in addition all optical surfaces are equipped with a full multi-layer broadband coating. Finally the beam-splitting mirror has a 99% dielectric coating and completes the excellent optical design.FEATURESEnables binocular observations with all telescopesRelaxed and comfortable viewingThree-dimensional viewing experienceSuitable for all telescopes with 1.25'' eyepiece connectionNo additional light path requiredNo magnification factor at the binocular attachmentEven low magnifications with large fields of view are achievableFor observing moon, planets and deep sky objectsPrecise and robust mechanicsSliding mechanism to adjust the interpupillary distanceDioptric compensation via fine helical driveWide eyepiece rotation clamp with automatic centeringFilter thread 1.25'' (M28.5 x 0.6mm) availableLens and mirror design made of finest Ohara (Japan) lanthanum glass materialAdvanced broadband multilayer coating on all optical surfaces99 % dielectric-coated beam-splitting mirrorHigh-quality hard-shell carrying case includedWHAT'S INCLUDEDBino Viewer DeluxeDust capsCarrying case 

Currently unavailable

£410.00*