Internal Links

to Mobberley pages



Alcock Page

Horace Dall

Asteroids and NEOs

Comet Images

Venus Images

Mars Images

Jupiter Images

Saturn Images

Supernova Images

Nova Images

Variable Stars/GRBs

Galaxies and Deep Sky

Lunar Images

Books & articles by Martin Mobberley

About Martin Mobberley



Total Solar Eclipses

Solar Images

Astronomical Web Links

Central Bureau
BAA Comet Section

Telescopes and Sheds

My first decent telescope was a home made 22cm Newtonian. Aged 15, I built everything,even grinding and polishing the mirror!

1973 M.M. and his 8.5" Newt.

1973 8.5" side view.

That telescope was largely inspired by Patrick Moore's 15" Newtonian which he started using in 1972, the year before I built my 8.5". In 2013 I completed a comprehensive biography of Patrick, entitled 'It Came from Outer Space, Wearing an RAF Blazer!' This was published in September 2013.

Biography of Sir Patrick Moore

Biography of Patrick on Amazon UK

I saved all my University sponsorship funds and, in 1980, aged 22, bought my 36cm f/5-f/20 Cass-Newt from AE. This telescope was used continuously at weekends from 1980 to 2003. In June 2009 I gave it away to AE telescope fan Mark Stuckey who is restoring it and setting it up in Norfolk.

14" reflector circa 1990

When I purchased my second property in Chelmsford, in 1991, I decided to have a monster telescope there. This 19.3" (49cm) f/4.5 monster by AE was used on weekday nights from March 1992 to August 2002. In 2008 I gave this telescope away to amateur astronomer Glyn Marsh who has set it up on the Isle of Man. I gave it away for two reasons... firstly, I was renting my old house out and I could not see future tenants actually wanting such a beast on their lawn! Secondly, a telescope that massive was just too much effort for someone aged 50+ to haul around the sky.

19.3" reflector in 1992.

In 1997 I purchased a 30cm LX200. I used it a lot, but it was plagued with gearbox/encoder drive failures. A pity, as those design flaws wrecked what was otherwise a very friendly scope. The run-off shed we built for it was a joy to use (and still is), but the telescope drive reliability was absolutely dreadful.

30cm LX200 and the author in 2001

Another shot of the LX200 in its shed.

A small animation of the run-off shed rolling back.

In 2003 I installed a Paramount ME plus Celestron 14. WOW...what a system! Total Reliability. Superb pointing and tracking. At last I had the perfect Deep Sky and Comet imaging system. It's a beauty.Even after 13 years the drive still works flawlessly. Software Bisque make absolutely superb mounts.

C14/ME plus L to R. Myself, Tom Boles, my Dad.

The C14/Paramount ME in its shed.

Myself + pride & joy...the C14/ME.

For my paper on the plastic run-off shed for this telescope please send me an e-mail and I will reply with the 660K pdf article.

In 2004 I decided I wanted a Newtonian which would stay in collimation and have excellent optics. That way I could dedicate the C14 for Deep Sky/Comet imaging and the lightweight fixed collimation Newtonian for planetary imaging. I purchased a 250mm (245mm clear) f/6.3 SPX Newtonian from Orion Optics UK. The mount is rather flimsy with such a long tube and I replaced the focusser with a JMI Motofocus, but, it performs beautifully on the Moon and planets (on non-windy nights!!)....a decent affordable planetary scope for visual or webcam work. In 2010 I upgraded to an Orion Optics 30cm f/5.3 Newtonian on a modified EQ6 Pro mount for lunar and planetary imaging.(I still have the 250mm Newt and made a Dobsonian mounting for it with my Dad's help).

Me + the 250mm f/6.3 Orion SPX.

Me + the 300mm f/5.3 Orion CT12L.

For my article about the user-friendly stowage 'kennel' for the 250mm Newtonian telescope please e-mail me and I can send you a 360K pdf document.

Advice on buying a Telescope

Over the last twenty years I have answered hundreds of E-Mails regarding how to choose a telescope. Unfortunately, for many people, buying a telescope is a disappointing experience. The popular magazines are full of glossy hype which can easily con both the beginner and the experienced amateur. In my experience a small proportion of telescope dealers are simply money-grabbing middlemen. Just compare the US and UK prices for, say, Celestron gear. Even after taxes, duty and importing costs are taken into account the prices in the rip-off UK are obscene. The only reasons why anyone would buy from such a dealer are when the manufacturer has an enforced dealer network (i.e. you cannot buy from the manufacturer) or when the telescope reliability is poor and a UK dealer will deal with the hassles of getting your lemon replaced, or if you just want something quickly that is 'in stock'. Historically, many telescope importers in this country have been rip-off merchants who charge, in pounds, what a telescope costs in dollars in the USA. In some cases these dealers control the market and have no competitors. The manufacturers will often refuse to deal direct with a UK client and if you order from a USA dealer, you end up with no warranty. This is a dreadful situation, but things are improving, mainly due to Chinese imports and cut-throat competition. Dealers can't rip you off when you can get a Chinese instrument for half the price! If you really want a good telescope that you can rely on and are handy with machine tools then you are best-placed to make as much of it yourself that you can. Home-made telescopes are the only ones you can trust 100%. However, rather predictably, most people would find it difficult to make their own optics and make their own drives and GO TO mountings. Essentially, many telescope dealers have one prime objective: they want as much of your money in THEIR wallets as possible, and any quibble over shoddy merchandise is a pain. If you send a telescope back to a few of the dodgiest people they will, eventually, swap it for someone else's lemon, and hope you won't spot the different fault!!!! With some franchises returning a faulty telescope from the UK dealer to the manufacturer is not part of the deal, or is not economically viable, hence the widespread practice of lemon swapping.....appalling!

I think the amateur astronomy community needs someone like Robert McCall to Equalize the odds between amateurs and the worst telescope dealers!

The Equalizer

Don't be fooled by every review in Astronomy magazines either! Magazines want the advertising revenue; they NEVER say a telescope from a major advertiser is a pile of junk!!.....If a telescope is really bad they may just refuse to review it, at best......As a telescope reviewer myself I try to get as many justified criticisms as I can in a magazine review, but not so many that the review will be scrapped. However, UK reviews tend to be a lot more honest than US ones, especially where US mags review the products of the largest manufacturers, i.e. the ones who fund the most adverts. The best telescope reviews of all are carried out by the French publication Ciel et Espace. They are infinitely better than any reviews in US or UK magazines because they actually use optical interferometers to measure the accuracy of the optics. Some of the Ciel et Espace tests have really exposed some lemons from major manufacturers. Rather than passing the standard 1/4 wave PV wavefront test, the benchmark for diffraction limited performance, many telescopes have turned out to be unfit for purpose. In the worst cases optics from major manufacturers have been 1/3, 1/2 or even 1 wave PV!!! In one case one example of a specific product turned out to be 1/1.4 wave PV but the second example was 1/6.1 PV. No consistency at all in quality control. Some manufacturers, like Orion Optics UK, provide a Zygo interferometer plot with their optics, thereby ensuring you know what you are buying. Telescope dealers live in total terror of a bad telescope review. The problem is that telescope dealers are not like the craftsmen of yore. They are, essentially, box shifters. They import hundreds, or thousands, of telescopes enabling them to cut costs, but they do not know whether their warehouses are full of good telescopes or lemons. A bad review can mean that they suddenly own 100,000 of unsellable stock if word gets around. I have carried out reviews for astronomy magazines where the dealers have gone berserk at even the slightest negative comment, claiming that "just by bad luck you got the only bad telescop in that would not be fair to mention that flaw" or "you must be mistaken, those telescopes have perfect optics".... Sometimes it has got quite heated. I must give credit to the UK magazines in these cases as they have always either published what I said or scrapped the entire review but paid me. They have never published my review with the bad points removed. In the USA things are not done that way. The major "magazine sponsors" tend to win.

What route you should take when choosing a telescope type is largely determined by what objects you want to study. If you are a lunar and planetary observer or even an occasional Deep Sky Observer, GO TO can be far more hassle than it is worth. With an accurately polar aligned telescope and a good set of mechanical R.A. and Declination circles any bright Deep Sky object can be located easily. GO TO is only an essential feature if you want to do a lot of imaging per night or are imaging faint hard-to-find objects or comets when using CCDs remotely. For visual observing I FAR PREFER a user-friendly telescope with good old-fashioned setting circles! What do I mean by user-friendly...? Well, a telescope that is accurately polar aligned and is in a run-off shed observatory that swings into action in, one where the telescope can be pushed around with ease and the eyepiece is always in a reasonably friendly position. There is nothing wrong with a good old long-focus Newtonian except the fact that you will need a sturdy mounting and manufacturers tend not to make long-focus Newts now for that very reason. In olden times telescope manufacturers made mountings with huge, beautiful, brass setting circles, which were a joy to use. But hardly anyone makes mounts with decent setting circles now...perhaps the Losmandy G11 is the only high quality survivor, and those circles are only 5-inch diameter. Of course, without circles you are forced to use Go-To, with systems that either make you press a dozen menu buttons before even engaging the drive, or systems that must use a PC or Tablet to control the, once again you are a slave to the dreaded Microsoft Windows and its upgrades..... Life was not always this damn complicated. In many cases Go-To is just technology for technology's sake and is very unreliable with small telescopes. With a big Dobsonian life is far more stress-free for visual observing. The picture link below (picture by Tom Boles) shows Patrick Moore's 12.5" f/6 Newtonian that he used for over 50 years. How many modern telescopes would last that long......very few !!

Damian Peach (L), Chris Lintott & me + Patrick's 12.5"f/6 Newt

Long focus Newtonians, on flimsy mountings are very prone to wind vibration. Newtonians longer than about 7 feet in length (2.13 metres) tend to be awkward to use when pointing at the zenith.... stepladders are required, and the eyepiece position can be most uncomfortable. However, something like a 10" (25cm) f/8 or 12" (30cm) f/7 Newtonian can be a real joy to use, on all objects. Lightweight Big Dobsonians, such as the 50cm f/4.5 Orwell Dobsonian (shown below with Nicky Gillard) can be user-friendly, low-tech and have a huge light grasp.

A very attractive system indeed!

Many people shy away from Newtonians because they have exposed optics that get damp and deteriorate. In this respect a good closed tube Newtonian, wins hands-down over an open tube one, as the tube keeps dew at bay. For the best planetary resolution a telescope must, must, must, must be precisely collimated!!! Also, the optics should be able to cool down quickly by fan-cooling. Mirrors thicker than 40mm have serious cooldown problems unless fan-cooling is employed. My 245mm f.6.3 Orion Optics Newtonian (plus mirror fan) is the best planetary telescope I have ever used. Some planetary observers line their tubes with cork too, to reduce tube currents.Many good planetary telescopes are comprehensively ruined by being in a huge un-ventilated dome with a narrow slit, a concrete floor and a metal dome.

So, what about Schmidt-Cassegrains? Why are they so popular? On the face of it they seem to be neither one thing or the other. They are not designed with the best planetary resolution in mind (although they can take superb planetary images) and they are not, at f/10, designed for low power. Their main strength relies on their compactness (ideal for a small shed), semi-portability, and the range of accessories available. Their small size is very compatible with relatively low cost GO TO mountings and, as the tube is sealed you don't get serious tube currents and the aluminium coatings don't corrode (although dew builds up rapidly on the corrector plate)... In the right hands, and when collimated on a nightly basis (a bit of a pain for most people) SCTs of 20 - 35cms aperture can produce breathtaking planetary images and great narrow-field Deep Sky images. However, SCTs are not without their problems and there has never been so much Hype surrounding them. There is no doubt that their main selling points are all based around their compactness and their GO TO features. SCTs are very rugged and user-friendly, and in the cold, damp and dark this can be by far the most crucial consideration.....Comfort at the eyepiece is SO important. It is quite amazing how small an observatory can be constructed to permanently house such a telescope. Karen Holland poses with her 10 inch instrument in the picture below.

A very friendly and attractive system!

However, certainly in my old 12" Meade LX200, the gearbox reliability was a fundamental weakness, as you would expect in any cheap system which can slew at 6 degrees/second, at which point the 60 cent (yep, that's what I said) Scalextric motor and plastic gearboxes fall apart.....Hardly surprising as the fastest components are whirring round at 14,400 rpm!!! I would never buy another Meade unless I was assured that the motor/gearbox had been totally re-designed. However Meade optical tubes are pretty good and for mass produced units work well. Just a pity they are attached to those horrible fork based scalextric toy car drives! In recent years drive quality has improved greatly and, for astro-imaging, buying a top notch equatorial mount is more important that the optical tube. The tube has no moving parts, whereas the drive does. Celestron SCTs are, undoubtedly, the best all round SCT packages on the market. Their 9.25 inch model has a slower primary mirror (f/2.5 not f/2.0) and can deliver superb planetary views. If anyone asks me what modest to large aperture SCTs I would recommend I always say, a Celestron 9.25, C 11 or C14. Just look at Damian Peach's images for proof...WOW! Mind you, there is some variability in optical quality here too and a rare C9.25 lemon with only 1/2 wave performance was tested by Ciel et Espace a few years ago! But Damian's two C9.25s were brilliant performers.

Meade SCTs seem to be good optically and the drives in the instruments of about 20cm aperture (LX200 and LX90) can sometimes last a long time if they are never used on fast slew. Remember, the LX200 mount was designed for use with a 20cm aperture load. But the failure rate on the big LX200s in the 1990s was woeful in my experience and countless other UK amateurs' experience too. I have a VERY long list of bad LX200 experiences with the larger 'scopes. Also, don't expect the tiny ETX Maksutov's to GO TO and hit the targets every time. Their Maksutov optics are good value and quite good optically, but the drives are plastic junk ! The large aperture LX200s tend to fail less if they are altaz instruments. It is the equatorially mounted instruments with CCD cameras on them that fail the most...and, strangely, the Dec gearboxes that have the most failures! As I've said, GO TO is not essential..... I quite liked my 1997 LX200 when it was working, but I always switched it on with a sense of's given me too much grief (expensive grief) over the years...... In 2007 I separated my LX200 tube from the fork and smashed the whole wretched drive unit to buggery with a sledgehammer....sheer bliss! The LX200 optics were remounted on an EQ6 Pro German mount, despite being on the EQ6 Pro's limit. Good riddance to that horrible old fork and scalextric motor gearbox! As I say, my experience with Meade has been pretty poor, but my experience with Celestron has been great.

So what about premium instruments that cost an arm and a Maksutov's and Maksutov-Newtonians or Dall-Kirkhams with Russian and Japanese optics etc. What about apochromatic refractors. Well, all such instruments are nice collectors items with a lot of associated kudos but, when it comes down to it (as Star Trek's Scotty might say) you canny beat the laws of physics. Where planets are concerned, atmospheric seeing virtually wrecks the view every night and reduces every instrument to about a 150mm aperture. But on really good nights, when a 200 or 250mm telescope can be used to advantage, you will still only be able to resolve to the theoretical limit of the aperture. It doesn't matter if your telescope is a 10,000 Maksutov or a 1,000 Newtonian, you will get the same resolution assuming the 'scope is collimated and has high quality optics. Don't be fooled by the hods of Maksutov dealers around, making absurd claims for their products...yes, some of the small Intes Micro Mak-Newt's are very nice instruments, but their dealers are full to the brim with bullshit and hype...especially the German dealers who import Russian optics and shove them in a giant metal bog-roll adding 5K to the price and giving horrendous thermal problems. Many telescope dealers have the same mentality as used car-dealers. Their sole aim is to get your money in their wallets.....You have been warned!! And they are just so full of hype for their products.....they really would be just as much at home selling dodgy merchandise at a car-boot sale....Do NOT be fooled by any of them !! Before a purchase ask around as to who are the best dealers....there are a few, but they are rather a rare breed. Essentially, a modest priced telescope, like a Celestron SCT, or a Newtonian, is as good as any other of the same aperture. The reason some people get better results is because they try harder, observe on more nights and catch the good seeing. For Deep Sky imaging of galaxies and faint comets an SCT is as good as any other telescope. For wider field imaging, then you may want to look at more specialised instruments.....but you will not beat a simple long-focus f/6, f/7 or f/8 Newtonian for resolution of planetary detail, provided you collimate and address the mirror cooldown issues.

There is little doubt that the Paramount ME (plus MX, MEII etc) is the best amateur telescope mount in the world where long term reliability is concerned, but as far as telescopes are concerned I would strongly recommend SCTs made by Celestron and Newtonians made by Orion Optics (UK). Other companies, like Losmandy and Takahashi (and at a higher price, Astrophysics) make excellent mountings too. I can recommend Ian King as a good UK telescope dealer. He is a leading astro-imager and knows about equipment and will give sound advice. Would you believe that I have actually been offered bribes from some telescope dealers to mention them on my web pages?! All sorts of free gear like big binoculars have been waved at me. Sorry, if you want to buy me off try a million quid....a pair of binoculars won't work! If I recommend someone it is because I know they are reputable, not because I've taken a bribe......!!! Disturbingly I know leading amateurs, and I do mean *leading amateurs* who have sold their souls in exchange for equipment, money, or massive discounts on equipment, just to endorse certain products to the hilt. I even know one very famous amateur who was conned into endorsing certain products while drunk! It is not easy to tell, on a typical night of bad seeing, if a telescope is 1/2 wave or 1/10th wave, especially in a brief glance. Testing a telescope's optics takes time and patience and a rigorous procedure over many nights, but this is rarely carried out. Some reviewers use the words 'crisp', 'stunning', 'diffraction limited', 'jaw dropping' in every review they make.....Why? Because they've been given the instrument for free or just can't be bothered to properly test it and get into a row with the dealer/importer. I like rows.....bring it on...If you really want to know how good a telescope is, drop me an e-mail first. I have used most brands and will tell you it straight. Scores of amateurs a year do contact me, knowing they will get the true picture and that I have not been bribed!! Bottom line is, do not believe a single word you read in a telescope advert, WHOEVER has allegedly endorsed the product.....*WHOEVER*.

My own Paramount ME/Celestron 14 is a CCD imagers narrow-field dream system and the Paramount ME is proof that there are still real craftsmen out there...the quality is bloody excellent. I use the C14 with a nominal 0.63 x compressor, taming it from f/11 to f/7.7. With an SBIG ST9XE CCD this gives me a field of 13' x 13'. My Orion Optics 245mm f/6.3 Newtonian and 300mm f/5.3 Newtonian are beautiful planetary telescopes and a joy to use for lunar and planetary work. I unreservedly endorse Orion Optics' Newtonian mirrors.

Both of my former massive Newtonians (the 14" and 19.3") were made by expert telescope builders Rob (mounts) and Jim (optics) Hysom, formerly AE of Luton; arguably, they were the last ever Great British Telescope builders who made their own mountings and optics. Real craftsmen, not just middlemen importers....a breath of fresh air! Being able to talk to the actual humans who hand built your telescope is, sadly, rarely possible in the 21st century....

Rob (left, mounts) & Jim (right, Optics) Hysom of AE in March 91

Video of the Hysom brothers in late 1991

Video of Rob Hysom installing my 19.3" in 1992

My AE 'scopes were good telescopes but real beasts to haul around the sky. After I developed a chronic back problem in the 1990s I decided I needed telescopes that were lighter and easier to use....I am always happy to answer queries about choosing and buying telescopes...indeed, I generally get many e-mails a week on this topic! But if you live in the UK and definitely want an SCT package I would simply recommend buying a Celestron (UK dealer is David Hinds, but Ian King sells them too) or, for the best optics, a Newtonian telescope from Orion Optics. There will always be aspects of any telescope that are far from perfect, but, in my experience, buying a Celestron SCT or an Orion Optics Newtonian is a far less traumatic and affordable experience than dealing with other products.....! No dealers or manufacturers are infallible though, some are just better than the rest. If you can afford it, mount such a telescope on a decent mounting, like a Takahashi, Astrophysics, Losmandy G11, Vixen Atlux or if you have the funds, a Paramount MEII/MX/MYT. There is a lot of bull and hype re. astronomy products, but the Paramount mounts are the real McCoy.....the best astronomical product you will EVER buy in your life !! The Celestron CGE/CGE Pro series is very nice too...the only downside, as with many German mountings, being the limited travel past the meridian, before you have to switch sides.... The SkyWatcher EQ6 Pro is an incredible value for money mount that can handle SCTs up to 11 or 12 inches. If you are awash with money and into Deep Sky imaging, a Planewave CDK on a Paramount ME is generally regarded as the ultimate system. What is the favourite visual telescope I've ever used ??? That's easy, Patrick Moore's 15" f/6 Fork-Mounted Newtonian....a real observers telescope if ever there was one, and being Patrick's telescope it just had 'presence'; a legendary instrument that I've now observed Jupiter, Saturn, Mars, the crescent Moon and Comet Machholz (2004 Q2)through.....with a rotating top end it was almost always at a nice height.... it was just great to use.

Richard McKim observing Mars using Patrick's 15 inch Newtonian on October 22nd 2005.

    Webmaster: M. Mobberley