The lens used on the Orion Sirius refractor telescope has a f/7.5. An advantage to the 80 mm objective lens. One of the lenses used is specially made to reduce the color infringing that occurs from chromatic aberration, causing the lines and blurring of color in the images that are taken. These have been a bane of astro-photographers for a very long time.

This telescope comes with the Sirius EQ-G Go-To mount to achieve stability while taking pictures. Both stability and control are needed when taking photographs with the Orion Sirius 80 EQ refracting telescope since it is such a powerful scope. This stability is provided by using the Crayford style focuser for both two inch and one and a quarter inch accessories while mounting your camera and imaging eyepiece.

The database has nearly forty three thousand images of the celestial objects for astronomical photographers to refer to when using the hand controller. This is used in order to zero in on the precise astronomical features desired. The mount has internal motors to stabilize the two different axis. One great feature is the periodic error correction to correct movement of the planets and stars as our earth rotates and moves through space; this stabilizing results in the wonderful photographs that are taken with this scope.

The price of the Orion Sirius 80ED refractor telescope is $1, 499.95; also payable is a shipping charge. This telescope is not intended for children to use unattended, it is intended for adult use.

The Go To hand controller requires a Windows 95 platform or later, a computer interface cable that is supplied, an RS-232 communications port on the personal computer being used, and a DC power supply that is at least 7.5V to 15V @ 100mA or greater output. It needs to have a 2.1 mm tip with a positive plug for minimal performance. It is important to make sure that the communication port on the personal computer is able to meet the high transfer rate. If it is not, the information can be uploaded at a lower rate, but the time needed will also be increased.

The tripod for the Orion Sirius 80 ED has 1.75 diameter legs made of stainless steel with a stabilizing tray that allows the telescope to be mounted easily and efficiently while in use. It requires a twelve volt DC battery or it can be adapted to use 110 volt power by using an adapter that switches from alternating current (AC) to direct current (DC). It has a one year limited warranty.

For the price the Orion in question is an excellent scope, geared toward the more serious amateur sky watcher.

Skywatcher Startravel 120 (EQ3-2) Short Tube Refractor Telescope Sale Price: £348.95

The compact Sky-Watcher Startravel series are two-element, air-spaced, multi-coated objective, achromatic refractors, and are well proven performers for "Rich-Field" views of star fields, clusters, nebulae, bright galaxies, planets, the Moon and, the Sun (with correct safety filtering!), as well as giving excellent terrestrial views. These wide-field short-tube telescopes are also highly portable. They also are popular for use as guide scopes on larger telescopes. All models excel as fixed aperture lenses for both Astrophotography and terrestrial photography. Their "fast" focal ratios combined with today's high-speed films make them useful for capturing lunar and solar eclipses as well as nature photographs. Features: -Direct SLR Camera Connection -Red Dot Finder -Dual-Fit 1.25"/2" Focuser -1.25"/31.7mm Star Diagonal -Multi-Coated Objective Lens -EQ3-2 Deluxe Equatorial Mount -Built-in Polar Alignment Scope Holder -Aluminium Tripod with Accessory Tray -38% more Light Gathering than 102mm

Simmons 525 Power 60mm Refractor Telescope with Tripod    £5.00

MEADE VISIOMAR 60MM REFRACTOR TELESCOPE PACKAGE    £19.99

NEW REFRACTOR TELESCOPE 70mm X 800mm BLACK FREE SHIP    £57.45

CLASSIC VIXEN CUSTOM 90M Refractor Telescope EXTRAS    £250.00

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Crusty scientists giving interminable lectures are given the boot and the Naked Astronomers focus on bright, breezy presentation that’s fun and informative.

The new stars of astronomy are a media-savvy group of physicians and researchers from Cambridge University who use radio, live lectures, and the Internet to strip science down to its bare essentials, and promote it to the general public.

Their award winning BBC weekly radio programme, The Naked Scientists, reaches a potential audience of 6 million listeners across the east of England, and also has an international following on the web.

Each week, listeners of all ages and backgrounds tune in on a Sunday evening to hear creator Dr Chris Smith, together with his entertaining sidekicks, interview renowned scientists and researchers from all over the world and take science questions on any subject live from the listening public.

The astronomy gig is presented by Ben Valsler together with Cambridge space scientists Carolin Crawford, Andrew Pontzen, Dominic Ford and a host of other cosmologically gifted contributors.

Now, you can download free podcasts and videos of news, views and experiments from the show from the Naked Scientists website.

In the latest editions, Ben and his team have looked at the source of the oldest light in the universe and asked if there is a planet in our solar system beyond Pluto.

The show and web site are great for astronomy enthusiasts of all ages who don’t want to listen to serious science debate but what their information in easily digestible byte-size bits.

What’s great is if you miss an episode, you can download a podcast or video cast from iTunes or the BBC iPlayer direct to your computer or portable media player and listen or watch when you have the time.

Astronomy is just one subject the Naked Scientists look at – their brief includes physics and archaeology.

	Celestron Ultima Refractor 80 - 45 List Price: £180.00 Sale Price: £130.85 Average Rating:
	A great all-around optical instrument. Great for observing nature and long distance spotting and since it is completely waterproof you can feel comfortable using it in extreme weather.

Celestron 73150249 LCM 60 Computerised Refractor Telescope List Price: £250.00 Sale Price: £218.55

There are estimated to be at least 70 sextillion (7 x 1022) stars in the observable universe and with the nearest one after the sun being 39.9 trillion kilometres away it is difficult to discover and appreciate their true celestial beauty without the help of a high quality telescope. This LCM 60mm Refractor telescope from Celestron couldn't be more perfect for the job with its NexStar computer control technology consisting of a database capable of locating over 4,000 celestial objects, with a built on Sky Pointer Finder scope to help you align the scope and achieve outstanding views of stars, moons, planets, comets and the endless array of other exciting features waiting to be discovered in the night sky. If you want to expand your exploration potential even further the scope also features flash upgradeable hand control software and motor control units for downloading product updates over the internet. Easy to set-up, the lightweight computerised mount prevents the need to lug around a bunch of heavy tools for assembly and can be easily and conveniently carried anywhere so you can find that perfect viewing spot where stability can be acquired with the aluminium tripod, even on uneven terrain in the great outdoors. In addition, there is also an included accessory tray for handy storage of all your add-ons and accessories so they are immediately to hand when required. To Infinity and Beyond! The Celestron LCM 60 Telescope is fully compatible with optional NexRemote telescope control software for full and advanced control of your telescope via a computer. "The Sky" astronomy CD-ROM software is also included in the package to provide a source of education about the sky and objects that you are viewing along with printable sky maps to help in your navigation of the heavens. Also ideal for terrestrial viewing, there will simply never be and end to your discovery and exploration of Earth and the great beyond! - Proven NexStar computer control technology

Celestron Ultima ED Refractor 80ED - 45º Sale Price: £332.85 Average Rating:

ED glass provides excellent color correction and razor sharp images for serious nature and bird watchers. ED version models are also ideal for virtually eliminating chromatic aberration usually seen during planetary and lunar viewing. Day or night, this scope is optimized to provide the sharpest images available. Model also features charcoal color rubber textured paint for secure grip. Soft-sided carrying case included.

Fun with telescopes

Has The Night Sky Always Fascinated You Since You Were A Child? Do You Often Wonder What Lies Beyond The Dark Expanse Above? Do You Want To Fathom The Mysteries Of The Infinite Universe?At Last! A Guide That Explains Astronomy And Telescopes In Layman's Language, Leaving All The Technical Jargon Out! Understand The Basics Of Astronomy And Telescopes... And Re-Awaken That Long Lost Discoverer Within You!* History Of Telescopes* The Evolution Of The Telescope* Historical Timeline For Telescopes* How Telescopes Work* Buying A Telescope* Finding The Telescope That Meets Your Needs* Factors To Consider When Purchasing A Telescope* Terminology* Astronomy 101* Zodiac Constellations* Andromeda* Build Your Own Telescope* Learn How To Build Telescopes* Make Your Own Telescope* Eyepieces For Telescopes* Why Using A Telescope Building Kit Is Convenient* Learn About Our Universe Using Telescopes* Basic Tips For Using Telescopes* Understanding The Value Of Telescope Lens----------------------------------------------------Dear ebook Readers:We are dedicated to providing our customers with cutting edge information with the latest and most popular ebooks & hot topics at very affordable prices. Our mission is to create positive change in your life. We carry hundreds of unique titles including "Literary Classics" under many categories for your convenience. Please click on the name "prime ebooks" at the top of the page, next to the title, or write "prime ebooks" at the search box and you will be taken to our main page in Amazon, where you will be able to check all the interesting, unique and informative titles that we carry at Amazon Kindle.

This is a popular refractor telescope for beginners sold under the generally reliable National Geographic brand through high street stores like Argos and Homebase for about £100.

This is a very basic telescope only suitable for an absolute beginner that gives limited views of the moon and planets.

With a 70mm mirror and magnification of x140, the National Geographic comes at the bottom end of the scale for viewing interesting objects in the night sky.

With manual focus and weighing in at 2Kg, this is a lightweight scope with a tabletop mount. The stripped down weight comes from many of the parts being moulded from plastic instead of metal.

If you are buying a first telescope for a budding astronomer, then be careful that the lack of visibility of distant objects this scope gives doesn’t put the junior stargazer off their hobby.

If the telescope is an introduction or taster for a youngster who you would feel safe handing a cheaper telescope to see if they are interested in astronomy, then this basic model is probably OK.

The detail is in the name really – it’s a spotting scope to line up a larger observing telescope rather than an observing scope itself.

The National Geographic is also woefully unsuitable for astrophotography as them kit comes without a counterbalancing weight.

For more serious astronomers, read our product reviews of Celestron, Meade or Skywatcher brands for refractor telescopes with similar mirror specification that far outperform what is really a toy from National Geographic.

It seems a shame that such a recognisable brand as National Geographic has lent its name to a product that really is not good value for the price – but in the end, telescopes are the same as everything else and you get what you pay for.

The technical specs are:

* Magnification 15 to 225x.
* Optimum magnification 75x.
* Lens diameter 70mm.
* Manual focus.
* Can be used for land and sky.
* Size (H) 121cm, (W) 78cm, (D) 78cm.
* Limited lifetime guarantee.

Simmons 525 Power 60mm Refractor Telescope with Tripod    £5.00

MEADE VISIOMAR 60MM REFRACTOR TELESCOPE PACKAGE    £19.99

NEW REFRACTOR TELESCOPE 70mm X 800mm BLACK FREE SHIP    £57.45

234 Power 60MM 700MM Altazimuth Mount Refractor Scope    £30.00

CLASSIC VIXEN CUSTOM 90M Refractor Telescope EXTRAS    £250.00

SKYWATCHER STARTRAVEL 102 REFRACTOR TELESCOPE OTA    £169.00

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Places are limited for this special treat observing double stars and star clusters with a professional astronomer on nine dates in December using the observatory’s 28” refractor telescope – that ranks as the seventh largest in the world.

These sky watches are only available in the lead up to the winter solstice because they are the shortest and darkest days of the year and often have clear skies due to the colder weather.

Completed in 1893, it was designed to keep the Royal Observatory at the forefront of contemporary astronomy at the start of the 20th century.

Astronomers utilised the telescope for research in to double star systems until its retirement in the late 1960s. It is now a central part of educational programmes at the Royal Observatory. A computer-aided guidance system and CCD camera have3 recently been added to the set up.

Cannonball bearings for rotating mount

Not only is the view of the night sky spectacular from the telescope, but the setting at the observatory in Greenwich, London, is also fascination as the telescope is now housed in an ‘onion dome’ resembling the Taj Mahal in India.

The dome’s shape was a solution to a design problem. The smaller predecessor to the 28-inch telescope had been housed in a flat-topped wooden ‘drum’ mounted on cannonballs which acted as ball bearings.

As the new 28-inch was eight feet longer than the previous telescope, a new dome was needed to avoid major rebuilding of the supporting brick tower. The answer was the 'onion dome', which bulges to a maximum radius of about five feet wider than the supporting tower walls. The cannonballs were also replaced with a more modern system.

Water powered drive froze in winter

The 28-inch lens weighs 200lbs and only two glassmakers in the world were capable of producing it, Commission to completion took eight years.

The telescope sits on an English Equatorial mount made for another telescope that was in use 30 years before the current refractor was built. The original drive was falling water that froze in the winter. Now the telescope is electric powered.

* Booking is required for the star nights by calling the Royal Observatory (020 8312 6608) for dates and availability. Tickets are £5 with concessions at £3.50.

SKYWATCHER 200P EQ 5 8 NEWTONIAN TELESCOPE    £153.79

Skywatcher 9mm Ultrawide Eyepiece 125    £29.99

SKYWATCHER SKYLINER 200P FLEXTUBE GO TO TELESCOPENEW    £799.00

SKYWATCHER SKYLINER 250PX FLEXTUBE GO TO TELESCOPENEW    £999.00

SKYWATCHER SKYLINER 300P FLEXTUBE GO TO TELESCOPE NEW    £1,399.00

Skywatcher Skymax 90 Tabletop Telescope    £110.00

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Sky-Watcher BK1206AZ3

The telescope gives fine astronomical vistas and close focus views of stars, galaxies, clusters, nebulae, planets, and the moon. With correct projection or filtering viewing the sun is also possible.

The BK1206AZ3 is a great terrestrial telescope for alt-azimuth or tripod mounting. A competitive price with good imaging makes this a good entry-level beginner's telescope with the bonus of easy handling makes the BK1206AZ3 a good travelling companion for a seasoned sky watcher.

The BK1206AZ3 has many similarities with smaller brother, a 80mm f/5 refractor. With a larger aperture, this model has a better capacity for collecting light at the same focal ratio and gives excellent wider field views.

Weighing only 3kg (6.5lbs) and measuring about 50cm (21.7") this is a very portable telescope.

As a refractor, set up is straightforward and takes only a few minutes. Minimal maintenance is needed as the optics are enclosed and factory collimated.

Mounting the telescope on alt-azimuth or equatorial mounts is quick and simple.

This telescope also has excellent performance as a fixed aperture, 510mm lens for astrophotography. The f/5 focal length combined with a digital SLR camera on a fast setting can capture excellent astrophotography. The telescope is equally at home taking terrestrial nature images.

An unshakeable equatorial mount and guidance system are needed for astrophotography.

A T-mount thread on the eyepiece holder allows direct attachment of an SLR camera and the optional 2.5" (60mm) extension tube allows close focus standard photography options.

The Sky-Watcher 4" (120mm) f/5 is recommended for urban astronomy – with a 13.1 stellar magnitude and 240x highest practical power.

The makers also recommend as an accessory a single axis EQ5 battery motor drive with hand controller that gives tracking 2x and 8x tracking speeds.

All in all, this refractor packs a punchy performance for a relatively low outlay against other models in the same class and is a great introduction to astronomy for a new observer or a competent and robust back up for a more experienced user.

SKYWATCHER 200P EQ 5 8 NEWTONIAN TELESCOPE    £153.79

Skywatcher 9mm Ultrawide Eyepiece 125    £29.99

SKYWATCHER SKYLINER 200P FLEXTUBE GO TO TELESCOPENEW    £799.00

SKYWATCHER SKYLINER 250PX FLEXTUBE GO TO TELESCOPENEW    £999.00

SKYWATCHER SKYLINER 300P FLEXTUBE GO TO TELESCOPE NEW    £1,399.00

Skywatcher Skymax 90 Tabletop Telescope    £110.00

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