Dedicated to Rob Nurse
One of the most egregious myths promulgated by contemporary telescope forum culture is that one has to splash out large sums of money for a high quality telescope. This is especially the case with refractor—obsessed enthusiasts who have reduced the hobby to an activity more related to pornography than anything else. Serving more as ‘phallic symbols’ than tools, they spend countless hours ‘drooling’ like animals over instruments with tiny apertures, and revealing little or nothing of any substance or lasting value. Over the last two decades their designers have systematically robbed an entire generation of amateurs with their ridiculously priced ‘peashooters’ and all for the sake of better colour correction. Yet all the while, the reflecting telescope was systematically ignored or down played; that is, until this author blew the whistle.
As a former victim of this dead–end cult, I came to realise through experience that despite owning and using a suite of high-end refractors (think Takahashi, Televue, Meade, William Optics etc), inexpensive mass—produced Newtonian telescopes from the Far East were not only superior to the latter, but were easier and more comfortable to use. In a previous blog, I brought people’s attention to the SkyWatcher Heritage 130P flextube Dobsonian that revealed its superiority to much more expensive telescopes (in this case a high quality 90mm ED apochromat) on all targets. The key to providing these high quality views involved careful collimation and adequate cooling.
These thoughts came flooding back to me after this author acquired a used SkyWatcher 130P optical tube assembly for the princely sum of £65 plus £10 delivery. Once it arrived I was able to collimate the instrument and test it out for its high magnification performance on good daylight targets, where it was found to deliver excellent images with no image breakdown at powers up to and in excess of 270x diameters. Such a telescope had a well figured 130mm (5.1 inch) f/5 parabolic primary mirror with a secondary mirror obstruction of just 37mm (so a modest 28 per cent), which is significantly smaller than their catadioptric counterparts, and so should enable one to see finer, low contrast details on the Moon and planets.
Now, I wouldn’t expect you to take my word for all of this. That’s why the reader will also take note of reviews carried out on the same instrument dating back over a decade ago. In this evaluation, for example, the highly experienced reviewer reported no image breakdown when the telescope was pushed to magnifications of 250x. This also resonates with the findings of this in depth review made by another experienced observer a few years back. Failing these, the reader should also take note of comments from a varety of other users here and here. In addition, in this short thread, posted in the Cloudy Nights refractor forum, the tester of essentially the same optics (the Astronomy Without Borders, One Sky Newtonian) reported that it was quite close in performance to a 120mm ED refractor costing many times more.
In previous work, I noted that a properly—tuned Skywatcher Heritage 130P proved to be a better double star splitter than a 90mm apochromat. In the same report, this author noted how this modest telescope was also capbale of rendering a much more convincing split of tight systems such as Pi Aquilae than a previously owned and thoroughly tested Skylight 4″ f/15 classical refractor. This should not surprise anyone; when conditions are good and the optics are properly aligned, aperture wins.
That said, this new blog will not concern the optics in the 130P pictured above. Rather, what I wish to write about here concerns the consequences of transplanting my modified Heritage 130P optics into the closed tube of the 130P. How would they behave?
The reader will recall that the primary mirror of the Heritage 130P was left unchanged as I judged it as perfectly adequate. But what I did do was to get it recoated with the finest coatings money could buy (still a modest investment) and in this capacity sent the mirrors down to Orion Optics UK to have them treated with their proprietary HiLux caotings for increased reflectivity, reduced scattter and optimal durability. I also replaced the existing flat with one of slightly smaller size (35mm minor axis diameter giving a linear obstruction of just 27 per cent) and higher quality (read optically flatter, but economically so). But how easy was it to house those optics in the new tube? As it turned out; it was quite straight forward!
The primary mirror transplant was the easiest to perform, involving a simple swap of the existing mirror of the 130P (also centre spotted!) with the HiLux coated mirror from the Heritage.
The secondary mirror swap was a little more challenging. In short, they were designed differently, so necessitating the removal of the existing flat on the 130P secondary and gluing on the new flat derived from the Heritage 130P. In all, it took about half an hour of open heart surgery.
Finally, to ‘turbo charge’ the new closed—tube optics, I borrowed some Bob’s knobs from my 8 inch Newtonian and placed them on both the primary and secondary mounting cells as indicated below.
Justifying the Transplant
While the Heritage 130P flextube telescope is ideal for airline travel (check out SteveG’s report on how he brought it to Hawaii while on vacation) and for vacations within the UK, I wanted to be able to mount the same optics in a more stable tube, especially since it would be used regulalrly for high resolution work over winter at my home. After having extensively used the helical focuser on the Heritage tube, moving to a proper rack and pinion was a huge step up in luxury. Have you any idea of how much easier it is to hold precise collimation with this new focuser? I can assure you that such an upgrade is nothing short of pure, unadulterated joy!
Rummaging through my old box of tricks, I retrieved a colour matched 6 x 30mm finder which is a huge improvement over the RDF supplied with the Heritage 130P. RDFs are only adequate if you wish to locate the brightest stars. With the 6 x 30mm finder, I will be able to pinpoint much fainter targets to increase the efficiency of my observations. All in all, Plotina has a new and more stable winter coat.
Proof of Concept: Reports from the Field
Plotina belongs to a long and distinguished family of true and original apochromats. It’s fast f/5 relative aperture enables me to go from 20x and a very generous 2.5 degree field to powers in excess of over 300x for high resolution work, particularly in my chosen area of interest; double stars. In many previous blogs, I have also stated how good this little telescope was on the Moon and planets. Here I wish to continue her legacy by fielding my beautiful little closed—tube Newtonian under the starry heaven………
Date: November 4 2017
Time: 20:00 to 20:45 UT
Seeing: very good (II), frequent squally showers moving in from west, some good clear spells. Full Moon in the east.
Polaris: Excellent star test. Intra and extrafocal images almost identical at 200x. In focus image revealed the faint, wide companion even in the bright moonlight.
Epsilon 1 & 2 Lyrae: textbook perfect split at 183x using Baader zoom at the 8mm setting coupled to a 2.25x shorty Barlow. Beautiful and faithful colour rendition of the four components.
Delta Cygni: A decidedly more difficult target, but once again easily handled and beautifully rendered at 244x using a 6mm Baader orthoscopic and 2.25x Barlow. A gorgeous, brilliant white Airy disk with a faint steely grey companion well separated from the primary.
Almach (Gamma Andromedae): not really a test but a sight for sore eyes in this fine little telescope at 183x.Lovely contrast.
Iota Cassiopeiae: the highlight for me this evening, now not far from the zenith. I charged the instrument with a 2.4 mm Vixen HR ocular delivering 271x. Focusing was very easy to achieve and I was delighted to see it deliver a bright and perfectly formed image of all three components in their true colours.
A quick look at the full Moon at 20x using my trusty 32mm Plossl revealed a razor sharp image rich in contrast and in a relatively enormous field.
Comments: To say that I’m pleased with tonight’s results would be an understatement! I am beside myself! The Vixen Porta II is a good mount for this telescope with its smooth slow motion controls on both axes, and with the eyepiece at a very comfortable standing height for me (I’m a six footer). All tested oculars come to a precise focus easily with the rack and pinion.
23:05 UT to 23:35 UT ventured out again to test a few other tricky systems
Rigel: Easy at 81x despite its low altitude (still a wee while from culmination)
Eta Orionis; A corker at 243x! Very tight pair split with this marvellous 5.1″ speculum at a suboptimal altitude.
Theta Aurigae: Now favourably placed high in the eastern sky. Easy split at 183x
Date: November 5 2017
Missed an early session this evening, as we ventured out for bonfire night. Anger nonetheless kindled against those supposedly ‘experienced’ peers who left this amazing, economical telescope in the dust. Why did you not test it? Too busy drooling were you? Why did you not advise your peers about it? How many amateurs might benefit from using this instrument?
You really need to examine yourself!
Shame on you!
Time: 21:45 UT to 22:30UT
Seeing: II, remaining very good, very cold and clear, bright Moon in the east.
Iota Cassiopeiae: Easily resolved at 183x but better seen at 243x
Theta Aurigae: Observed once again this evening. Companion beautifully resolved from primary at 183x
Pushed the telescope hard on the waning gibbous Moon this evening. The telescope delivered wonderful images at powers from 20x to 325x! No image breakdown recorded at any of these powers. Wonderful images delivered in these sub–zero temperatures.
Comments: Lambda Cygni (0.9″) is now past its best and slowly sinking into the western sky, but I will attempt 52 Orionis (1.02″) and 36 Andromedae (1.14″) over this coming winter. I cannot for the life of me see why Plotina cannot resolve these systems under good conditons. Can you?
Date: November 6 2017
Having a proper finder is a wonderful upgrade to the RDF supllied with the telescope. As stated previously, RDFs are only useful with the brightest stars and often, in colder conditions especially, the battery ceases to deliver its power rendering such a device useless. What is more, as a guy who likes to do all his observing without electronic appendages, fitting a traditional finder to this small Newtonian made a great deal of sense. When properly aligned it’s possible to centre objects, even at high magnification, increasing the efficiency of my observing sessions with this telescope.
Of course, one of the great joys of using this f/5 Newtonan system is the substantial increase in light gathering power it delivers over other other telescopic designs. Actually, it’s an enormous increase over a typical, small grab ‘n’ go refractor or Mak and will make your ‘quick look’ or grab ‘n’ go excursions far more rewarding than using an 80 to 100mm refractor, say. F/5 is not so fast that one requires a coma corrector or some such and the field of view with a modest 32mm Plossl is quite well corrected across the majority of the expansive, 2.5 degree true field. One thing is certain; this telescope will be an absolute ball to use in the exploration of the winter deep sky.
Having a new winter coat avoids the need to fit a makeshift light shroud to the upper tube assembly, such as is the case with the Heritage 130P/ One Sky Newtonian. This affords a greater degree of protection against dew and stray light combined. The increase in mass is negligible too; you can pick up the ‘scope with one hand or carry it under your shoulders even over a considerable distance.
As I noted with the Heritage 130P, quick acclimation is eminently possible with this telescope and my observations thus far made with the closed tube 130P give me little cause to think that its cooling off time will be substantially increased. 15 minutes is probably all you need, so even the laziest of you readers can get to work on the sky quickly and easily.
As described previously, I use a simple, inexpensive laser collimator to get quick and accurate alignment of the optical train. I consider the laser collimator a great improvement over the traditional ‘collimating eyepiece.’ My high magnification tests conducted thus far show that the more stable housing of the optics in the 130P maintains this collimation significantly better, so there is far less anxiety involved in moving the telescope about.
One of the greatest (and largely unsung) assets Newtonians have pertains to their ability to be collimated rapidly. I’ve lost count of the number of stories I’ve read of folk who accidently whack their refractor or Mak tubes off a wall or door or some such and then worry that the optics may have gone out of alignment. For a Mak, the issue can be resolved at home, but not very easily. For a refractor, you’ll likely have to send it off to some specialist for proper realignment of the lens elements; and at an additional cost to you. All of this, of course, is superfluous to the man who learns to collimate his Newtonian. You can bump it off any wall you like and still have the reassurance that it will be working optimally in a matter of minutes.
In this capacity, Newtonians are the ultimate, low stress telescope.
The weather has nose dived in the last twelve hours back to mild, wet and cloudy. Time to take a break from this blog and return again when conditions permit more testing.
Toodleoo the noo.
Date: November 7 2017
Time: 22:11 UT
Seeing: I to II, excellent, good transparency, waning gibbous Moon, not too overwhelming (yet).
While some of you were drooling on the fora, I was busy finding 36 Andromedae while the Moon was still low and monitored it at low power until it crossed the meridian at 22:11 UT or thereabouts. Charging the 130mm f/5 Newtonian with a 2.4mm HR ocular delivering 271x I can report a fine split of this system. Both stars separated by a sliver of dark sky and distinctly yellow in colour. The view was even more compelling at 325x. Perfect Airy disks! This is a magnitude 6/6.5 pair and the separation is 1.1″.
This telescope rocks!
Let goodwill and common sense prevail!
As always, I would encourage others to see if they can split this system with a 5 inch Newtonian reflector. Make sure your optics are well collimated and the instrument fully acclimated (you don’t need a fan either). You’ll be very surprised what you will see under good conditions!
As you can gather, I have dedicated this blog to Rob Nurse, who has started a friendly correspondence with me. I learned that back in the early to mid 1990s, Rob employed a little Tal 110mm f/7.3 to divine some pretty tight doubles using this reflector and has been following my work. Below is just one page of some of his results (used with permission). This is more evidence that well made Newtonians are excellent double star telescopes.
I hope you can see that he managed to split pairs down to about 1.3″ and his success was better the higher in the sky these pairs were situated. I suspect that he was wasn’t trying particularly hard to push the instrument though!
We need to keep working hard to root out the evils in this hobby, so feel free to help out if you can.
Date: November 8 2017
Last night was very exciting but I had to cut it short. 36 Andromedae was not a particularly difficult system for this telescope. For the record, it’s very close to the Dawes limit for a 4 inch unobstructed aperture. But in the right hands, the 130P is capable of doing significantly better than the finest 4 inch refractor money can buy. If you think otherwise, you’re simply deluded. Like I said before, I once drooled over a very fine 4″ inch f/15 refractor that set me back a small fortune. Yet this little reflector in my possession can outperform it; and I only needed to do some simple tests to affirm this. And no amount of justifying can change that fact.
For me, the reflecting telescope has been an instrument of liberation. Isaac Newton( 1642—1727), arguably the greatest scientific genius ever to have entered the human arena, invented this marvellous telescope. I think this was meant to be. But I hope you too can learn something from the hard lessons I have learned. The beauty of the Lord’s created Universe is not to be enjoyed only by an exclusive few. It ought be enjoyed by everyone. And the Lord has made this technology available to all at relatively little cost through the reflecting telescope. Pride has died; gratitude is born (sic gratia non superbia).
52 Orionis is just beyond the capabilities of a 4 inch aperture but should be quite doable with the 130P. I will have to wait for another good night to ascertain this.
Rob was also kind enough to provide a short list of other systems that will be interesting for those with small reflectors to visit over the course of the seasons. Some of these entries are dated but it would be fun to visit them nonetheless to see how they’ve changed over the years.
I’m blessed by having more quality eyepieces than you can shake a stick at but you don’t need to have the finest collection of ultrashort focal length oculars to boost the power in a short focus reflector. By far the most economical way forward is to invest in some Barlow lenses that can boost the power of the eyepieces that you may have in your possession. For example, the Baader 6mm classic orthoscopic yields 325x with a 3x shorty Barlow and 243x with an economical 2.25x Barlow. My excellent Parks Gold 7.5mm ocular is also a great choice when coupled to a 3x Barlow yielding 260x. You can also get good results by Barlowing a medium focal length Plossl (a 9mm is a good choice).
Date: November 9 2017
Faster, Cheaper, Better
If you’re thinking ‘phallically,’ then you’ll likely say the 90mm refractor is better; afterall, it has a smoothly gliding extendable dewshield and a super ‘sexy’ dual speed 11:1 focuser. It resembles a phallus too and ‘looks the part’ alongside you in a comfy, twoseater sports car. But if you’re thinking Biblically, using your eyes and brain as God intended you to use them, then it’s easy to see that the 130mm gives a much brighter, cripser and more detailed image at the same magnification and all with perfect colour correction (the refractor only approximates true colour correction). In previous work, I showed that the 130 Heritage truss tube configuration could split tighter double stars, resolve finer planetary details and pulled in fainter deep sky objects than the aperture—challenged refractor. Using inductive reasoning (but also adding my own ongoing experiences to the mix), the closed tubed 130P ought to do likewise….. and it does.
Here’s the rub though. The optically inferior refractor is valued much higher than the reflector; many times more in fact. Why? God only knows! But I’ll give you my opinion; because it is seen through the corrupt lens of the phallus. You’re literally thinking like a Dick. That’s the ridiculous situation that has precipitated because of our blinkered perception of value and which has gone largely unchecked for nearly three decades. What’s the refractor really worth? To a visual observer, slightly less than the reflector, surely?
Don’t be a phallus.
Date: November 10 2017
In case you’re wondering, the 130P is actually slightly lighter than the 90mm Apo and should probably cool off just as quick as the latter. It’s also small enough to fit in a comfy twoseater, so there’s absolutely no excuse not to consider it as a most powerful grab ‘n’ go telescope.
This very morning I set up Plotina in my back garden to exploit the feeble autumn sunshine, looking at the now denuded branches of deciduous trees located a couple of hundred yards distant. Incredibly, I was able to crank up the power to 406 diameters using a Vixen 1.6mm HR eyepiece and the images garnered were beautifully sharp and rich in detail. That’s over 80x per inch of aperture folks; no’ bad…..ken.
Yesterday evening the veteran Romanian observer, Mircea Pteancu, kindly reminded me that he has managed good splits of 52 Ori , 36 And, Antares and Nu Sco, using a homemade 127mm f/7 Newtonian reflector, adding another experienced voice to the list. You can read more about his findings here. F/7 must be a wonderful place to be in a 5 inch reflector. I bet it would hardly ever need adjusting and focusing would be child’s play. I’m envious of f/7 but f/5 will do admirably.
Low Power Sweeping
After I had finished with the students and grabbed a bite to eat, I noticed that there was a few clear spells and no Moon between 8pm and 9pm local time, so off out I went with the 130P and decided to stick with just one eyepiece; my good old SkyWatcher 32mm Plossl. The markings on the barrel are long gone by now but there’s still no mistaking it! Truth be told, it is one of my fondest and most used oculars. Delivering a power of just 20x in a splendid 2.5 degree field, I enjoyed beautiful views of the Pleiades, now climbing higher into the eastern sky. From my dark country home, the hinterland to this much loved open cluster is coal black in the telescope, its individual stars, tiny incandecsent jewels shining through the darkness. The 32mm Plossl gives a very well corrected field, with stars even at the edge presenting as very acceptable. It’s comfortable eye relief makes it a good choice for those who wear eyeglasses.
From there I ventured high overhead to the Perseus Double Cluster and boy was that a sight for sore eyes! It’s singular beauty never fails to set my heart racing and it was splendidly framed in the wide, well corrected field. From there I inched the telescope further eastward, centring the wonderful Alpha Persei Association in the 32mm oculus. Thereafter, I swung the ‘scope back westward into Cassiopeia and enjoyed staring at the fascinating ET cluster for a wee while. It actually looks best in the Newtonian, as the upside down image presents it the ‘right way up’, as it were. Sweeping the instrument through this constellation is always a special treat, with myriad Milky Way stars dazzling the eye.
Spotting a hole in the clouds in eastern Pegasus and Andromeda I homed in on the great spiral galaxy M31 now very high up, its bright, lenticular core showing up very well together with its gradually fading spiral arms. The two satellite galaxies were also apparent with averted vision. Moving west into Cygnus, I enjoyed the radiant colours of 30 and 31 Cygni, which are much more compelling in this telescope than they appear in large (70mm) binoculars. Comely Albireo was also resolved at this low power.
Finally, I swung the telescope over to Auriga, and after a minute admiring the silent beauty of brilliant yellow—white Capella and its starry hinterland, I swept through the belly of the constellation, seeking out the compact open clusters; M36, M37 and M38. Though I could have done with more magnifying power, I was pleasantly surprised how well they looked at 20x.
I’m deeply impressed with the performance of this economical telescope, being capable of every kind of astronomical application you might need it for. In fact, it has no significant weaknesses. It’s very lightweight, so even those who are frail can get fair use out of it. Indeed, though I am personally enjoying the prime of my life, I can easily lift the telescope on its mount a considerable distance with only one hand. It’s easy to store too and won’t take up much room. I keep mine under my bed lol! It’s an unbeatable bargain for those on low incomes as well as pensioners, and will delight its owners with years of productive use.
Date: November 13 2017
The 130 is so lightweight that it can be used profitably on a number of economical mounts. I generally use the Vixen Porta II with this instrument. The wonderful thing about the Porta II is that the tension on both axes can be adjusted to perfectly match the mass distribution of the telescope. The supplied hex wrenches that sit under the mount head can be accessed at a moment’s notice to make those small but important adjustments to the tension that make the telescope move very smoothly, even at high power.
Because the telescope has a standard set of tube rings, one can also adjust the position of the instrument’s base so that observing at the zenith is easy to achieve.
The Porta II can also be adjusted in height to permit very comfortable, standing or seated observations. Thus far, I’ve only observed through the telescope in the standing position, as the weather has been so unsettled that a shower can turn up necessitating the instrument’s rapid transport indoors. But I hope to enjoy this telescope with a comfortable seat during more settled spells.
The same telescope can also be neatly mounted on the simple table top mount supplied with the Heritage 130P. When mounted on a small table, it can be used with ease for low and medium power sweeps but I would recommend a more sturdy mount for the highest power applications.
And for those who enjoy equatorial mounts, the instrument is well matched to the fairly lightweight EQ 2 mount. Indeed, one can purchase the 130P along with the EQ 2 mount as a package from SkyWatcher or Orion Telescopes & Binoculars(USA). These mounts can easily be upgraded for smooth motorised tracking too. See here for a quick over view of its operation on such a mount.
There is also a number of lightweight, fully computerised GoTo mounts that can be mated to the 130P if that is your thing.
These are just some of the mounting configurations you can use with this telescope. None will break the bank and all should provide years of hassle free use. My preferred mounting for this fine instrument is the Vixen II as I’m not entirely bowled over by equatorials. It has given this author several years of flawless use with a number of telescopes, and has travelled with him the length and breadth of the country.
During the middle months of the year, where sunlight is abundant and the length of the day is long, smaller aperture spotting scopes make near ideal tools for studying nature, but as winter approaches (and at dusk and dawn) at high northern latitudes, having decent ambient light becomes much more of an issue. This is where the significantly increased light gathering power of the 130P really shines. On a dull, overcast, winter day, only a couple of hours of decent lighting is available for nature studies. But it is in these conditions that the 130P shows itself much superior to conventional spotting ‘scopes. Where powers of 100x or above are really stretching the 80 or 90mm ‘scope, powers twice that and more are achievable with this ultraportable 5.1” Newtonian.
Of course, the Newtonian reflector provides an upside—down view of terrestrial scenes and while there are ways of getting decent right—side—up views, in practice it matters very little. When coupled to a digi—scoping device, the images can be easily inverted later on your pc. When you’re examining the fine structure of tree trunks and branches or the splendid high magnification detail of leaves, rocks and wildlife in ultra—high resolution, you’ll soon forget about those upside—down images and delight instead on the rich details afforded by this optically excellent light bucket.
Because it gathers a very generous amount of light, you can also employ filters such as a polariser to cut through glare in the landscape and increase contrast on the brightest days.
Indeed, using both the Heritage 130 and the closed tube 130P extensively during the day has caused this author to question the dominance of other kinds of telescopes in daylight applications. It might not look quite as sexy as a Questar 3.5 or 80mm shorttube refractor but one look through the Newtonian will quickly reveal its clear superiority to the latter. And of course, there will always be some who balk at the Newtonian and reject it only because of its inexpense; sad I know, but that’s their problem and not yours, right? lol!
Don’t be a slavish follower of fashion; take your daylight observing elsewhere.
Date: November 14 2017
The last several nights were either cloudy or too unsteady to continue some of the high resolution work mentioned previously. Many of the clearest nights have been cold but very turbulent owing to strong northerly air flows, which always deteriorate high magnification views in these parts. Things were so bad in the wee small hours of Monday morning last that the telescope was unable to steadily hold the four brightest members of the Orion Trapezium! But I am thrilled to bits with the deep sky performance of the 130P. The Great Nebula still looked magnificent in the opulent field presented by the 8mm setting of the Baader zoom eyepiece (81x) and far more compelling than either of my shorttube refractors (80 and 90mm) can ever deliver. It’s a powerhouse of honest to goodness performance!
I will report some more once conditions improve.
Date: November 16 2017
I enjoyed another bright and sunny late morning/early afternoon session with the 130P. I re—tested its ultra—high power performance on daylight targets. I can again confirm that the instrument is good to go at 406 diameters i.e. the image remains fine and bright and beautifully crisp across the entire field of a Vixen 1.6mm HR ocular. For the most part though, I am sated under these conditions by the 183x vista rendered by my Baader zoom and dedicated shorty Barlow, which delivers an amazing 0.4 degree true field.
Iblis scurries to and fro, scheming, desperately seeking to inflict harm on her. Yet no matter how much mud the enemy flings at Plotina, nothing sticks.
Like a faithful Collie, she just goes on strutting her stuff, by day and by night; naturally, gracefully, effortlessly; delighting her master.
Tonight looks good for yet another session under the stars.
Time: 22:30 UT
Seeing: 2.5 Ant, excellent sky transparency, brisk westerly winds driving in some intermittent wintry showers.
Tonight, I set up Plotina to assess the seeing and targeted Theta Aurigae now situated favourably well above the horizon in the east. The telescope delivered a wonderful split of its B and C components at 271x. The former is tucked up real close to the substantially brighter primary (magnitudes 2.6 & 7.2, respectively) with a separation of about 4″.
One of the keys to getting success out of a Newtonian telescope on such high resolution targets is to be patient. The telescope generates some thermals especially on colder nights, where the high magnification image breaks up momentarily before coming back together again. One moment it morphs into a swollen mess of light but as it moves across the field the image settles down and delivers beautiful, textbook perfect images. You need to spend time with the telescope to learn how it behaves before you can get the most out of it, or to speak, with gravity, concerning it.
But I had bigger fish to fry. High overhead at this latitude on mid—November evenings lies mighty Cassiopeia, and under these fine conditions I homed in on Psi Cassiopeiae, a system I have given mention to in regard to a very fine Orion 18cm f/15 Maksutov cassegrain I put through its paces a few years back. The primary shines with a beautiful soft orange hue but about 20″ off to the east of it lies the faint C and D components (magnitudes 9.2 and 10.0 respectively) and are separated by a mere 2.3.” The challenge is to be able to see them clearly. Needless to say, the large Maksutov made light work of these faint companions but my field notes show that I could also see them with my very fine 5 inch f/12 classical achromat but only with a concentrated effort. The test tonight was to establish whether or not I could do the same with this 5.1″ f/5 reflector and I can report that the answer is affirmative! I employed a magnification of 183x and a concentrated gaze. This is not an easy target, but it is just possible with this telescope under near ideal conditions.
What does this observation establish you may ask?
It shows that the light gathering power and resolution of the 130P is on par with the 127mm f/12 refractor.
No’ bad, ken.
I ran in to inform my wife of my progress but loitered too long beside the fire, unfortunately. When I went back outside, it was raining and the poor telescope (and some choice oculars to boot) got a substantial drenching!
But the 130P is no’ a Big Jessie ‘scope and a dousing of water from heaven does little to dampen its enthusiasm.
Date: November 17 2017
If it wasnae fur yer wellies, where would ye be? lol
You’ll be glad to know that Plotina made a full recovery and is now ready for more action under a starry sky.
Weather still looks iffy though but since the telescope cools off as fast (maybe faster; greater surface area an’ that?) than a small refractor, it can still be used as the ultimate shower dodger.
Date: November 18 2017
More on Faster, Cheaper, Better
It was another crisp, cool and bright day here in Scotland. And with some free time to cogitate upon the 130P, I can confidently report that its performance lies midway between a high quality 4 and 5 inch refractor, but at a much reduced price to the consumer. As I’ve demonstrated, it ticks all the boxes that an ‘apophile’ might make in an argument concerning image fidelity, portability, rapidity of cooling etc. How it looks should be of little concern to a dedicated observer, but maybe some value ‘form’ over ‘function;’ why, I’ll never understand!
Telescopes are not idols.
It must be stressed that my major objection to apochromatic refractors is their exorbitant cost per millimetre of aperture; a price I am personally unwilling to pay as I can make much better use of my disposable income (I’m frugal and I consider that a virtue). Simply put, their prices are far higher than virtually any other type of optics on the market and that alone will make them a prime target for new and more cost—effective technologies now being developed. Unless the prices of these instruments are significantly reduced, they will be superceded by new technologies that are faster, cheaper and better. For example, a few years back, this author introduced the amateur community to a novel flat lens technology that will surely revolutionise telescope optics if the good Lord grants us enough time to see it to fruition. The technology (now being developed for visual wavelengths as the article indicates) is scalable and affordable. Let us hope that they succeed in their researches!
In the meantime though, it pays to take a hard headed look at other affordable telescopes already on the market, and in the same aperture class as the 130P, to see how they measure up. As I said before, the 130P is in a completely different league to 80mm ED ‘scopes and 90mm Maks (including the venerable Questar 3.5). Consider if you will, the Celestron C5, reviewed here in good detail. The instrument is quite portable but will take considerably longer to acclimate if taken from a warm room to the cold night air. With a focal length of 1250mm (so f/10), it offers up a maximum true field of about 1.25 degrees; that’s only half the field possible in the 130mm Newtonian! And with a central obstruction of 37.8 per cent, its performance on lunar and planetary targets will be noticeably inferior to this reflector (recall it’s only 28 per cent and mine was reduced to 27 per cent). Price wise, you can purchase a 130P and decent mount for much less than the C5 optical tube assembly alone!
Better still is the 127mm f/12 Maksutov. This has an even longer focal length (1500mm), reducing the maximum true field to about 1 angular degree. But it still has a central obstruction of 33 per cent and takes quite a while to acclimate (that is, if you’re unprepared!). 33 per cent is, of course, better, but not nearly as small as the obstruction in the 130P. This means that if the latter optics are decent, well collimated and suitably acclimated, it should outperform the former on low contrast targets under good seeing conditions. In this realistic review, the author correctly concludes that the 127 Mak rivals that of a top class 4 inch refractor in average conditions. So a good 130P (also cheaper than the 127mm Mak) such as the unit in my possession, should do that little bit better don’t you think?
Date: November 23 2017
A Virtuous Telescope
After several days of rain and cloudy skies, the weather has turned much colder once again, bringing bright blue skies by day. Much of the north of the country got its first fall of snow in the wee small hours and we even got a sprinkling here but it didn’t settle. Making the most of the bright light, I once again tested the ultra–high power performance of the 130P on a number of targets between 50 and 200 yards distant. Charging the telecope with a power of 406x, I got precisely the same results as I obtained before; namely, the telescope yields very sharp and detailed images (n=3) at this power, testifying to the quality of the optical system. This power ought to be useable on the best nights to ferret out the tightest doubles accessible to the instrument.
Today, of course, is American Thanksgiving Day, and I would like to wish all my US–based readers happy holidays!
Conditions look clear for tonight, so I may be able to report back later this evening. Tomorrow we travel 127 miles north for a short vacation. Needless to say, Plotina will be travelling with us in the hope that I can enjoy a short adventure with her under a very dark, winter sky.
I could do with a carry case for the telescope. But it’s certainly not an essential feature. Afterall, the instrument can be carried in your lap, or safely stored with the rest of the luggage in the boot of the car. And even if it gets knocked about, it’s easily remedied by a quick and accurate collimation once we arrive. No sweat!
I’ve just noticed that the eyepiece holder can accommodate a T2 adaptor to mate a camera or webcam to the telescope. That’s a nice touch, but something that doesn’t interest me, as I’m purely a visual observer, but it does means that the instrument can be used to do some entry–level imaging when coupled to a motorised tracking mount.
Gosh; are the virtues of this telescope ever going to come to an end? I wonder!
Time: 17:00 to 17:30 UT
Seeing: II–III, very cold, a little turbulence, crescent Moon setting in the southwest, no cloud.
This evening I obtained a beautiful split of Mu Cygni at 271x but a decidely better one at 325x. Secondary situated northwest of primary and much better resolved than in the smaller refractors (ST80 & ED90).
Lambda Cygni attempted also; very strong elongation but not resolved at 406x.
Some cloud moved in after 5.30pm local time raising the temperature by a couple of degrees in the process. Hoping for more observations later tonight.
Date: 24 November 2017
Seeing: II–III, remaining a little turbulent, cloud clearing away after 23:00 UT
A few high resolution targets selected this evening
Eta Orionis: a very nice split at 271x, pure white components; images improving as the system approached the meridian afer midnight. Twenty minutes can make all the difference on this mediocre night.
Theta Aurigae: Now very high up and beautifully presented in the 130mm speculum at 271x.
Rigel: Not really a high resolution test so much as an indication of how much light scatters at lower altitudes; quite low down when observed but faint companion easily picked off in the high fidelity field of my very good Parks Gold 7.5mm ocular delivering 87x.
52 Orionis: A good result! Stars appeared elongated at 271x and 325x but not resolved. Will have to wait for another good night to crack this 1.0″ pair. But my observations give me confidence that it will yield in good time.
Time: 11:30 am
Inbox filled with Black Friday junk; the unpleasant side of global consumerism.
All deleted now!
Thanks but no thanks!
Date: November 27 2017
Well, our weekend away went swell. Even though we left with about an inch of snow on the ground, the main roads had scarcely any of the white stuff. Indeed, it was only to be found in the high places along the route. Arriving at our destination at dusk on Friday, the sky remained resolutely clear, but a bitter north westerly wind made it feel a lot colder than it was (fluctuating by just a couple of degrees above and below freezing). After we had settled in, I took the little reflector out of the boot of the car and secured it on its Porta II mount. Checking how well the instrument maintained collimation, the laser showed only slight misalignment of the secondary mirror. Indeed it was pefectly useable as it was for low and medium power work up to 120x. To be honest, I wasn’t really surprised. You see, the acquisition of her winter coat has made the telescope much more robust. Nevertheless, I made that slight tweak to the secondary to bring it into perfect alignment. No sweat; it only takes a few seconds.
A beautiful, late crescent Moon greeted us in the south southeast, the magnificent orb culminating at about 5:30pm, just above the tree line of the grove that marked the edge of the property. In a race against time, I fetched my trusty Baader zoom and dialled in the magnification that would provide the most majestic view; the 8mm setting yielding a power of 81 diameters, which would frame the entire crescent with plenty of dark sky to spare. Though the air was a tad roily, the image was still breathtaking!
Because we had company, that was all the observing I got up to, apart from a wonderful half hour in the bright, early afternoon sunshine of Saturday (406x testing very favourably at this location too, so n = 4). Yet even these brief spells of observation were more than enough to reaffirm the worthiness of this instrumrnt as a choice travel ‘scope. Indeed, it has already been with me on several other trips the length and breadth of the country, where I discovered that skies can be great away from home.
There it is!
Travelling: yet another virtue of the telescope.
While carrying out my observations I became increasingly aware of the tendency of the simple 6 x 30mm finder to slip out of position. Even with an elastic band in place under the collar of the finder bracket, it still slipped more than I liked, necessitating a small readjustment in the field. This is a minor nuisance, and one I could easily live with, but I also discovered that the bigger, 9 x 50mm finder that normally sees light astride my main telescope; a 20.4cm f/6 Newtonian, also fits the 130P perfectly!
A good telescope with an aperture of 5.1 inches really ought to have an equally good finder. Unlike the 6 x 30mm, the 9 x 50mm is much less inclined to go out of alignment while in use and ought to pull in even fainter objects, increasing the 130P’s overall efficiency. The small additional mass up front is easily handled by the Porta II mount.
I think that’s a good thing. Afterall, the equipment I have already invested in ought to be able to serve me in diverse ways and when I want to go for a serious night out with Plotina, I’ll be needing a serious finder to complement her excellent optics. In fact, I’m thinking of doing something similar with Gaius, my 80mm f/5 achromatic. It would be just dandy to use it on either my 8 or 12 inch telescopes!
This afternoon, I took the 130P out for another look at the landscape. Focusing on a conifer tree some 150 yards distant, I once again obtained a tack sharp image at 406x (n=5). The instrument is probably capable of doing 100x per inch though (used to study tiny planetary nebulae and very tight doubles under good seeing conditions). I consider that exceptional!
The Lap ‘Scope
Can Plotina be used without a mount?
Back in 2010, amateur astronomer, Douglas Bullis, wrote an interesting Cloudy Nights article describing his “lap ‘scope,” a bare bones 6″ f/5 Meade Schmidt Newtonian(SN6). In the article, Bullis made the bold claim that the modified instrument was not a grab ‘n’ go ‘scope so much as a grab ‘n’ sit instrument. Be sure to check out the comments as well! Having owned and used a SN6 for a couple of years, this author is confident that the 130P would make an equally good if not better lap ‘scope, allowing one to make 20x sweeps, delivering a 2.5 degree field.
Of course, Bullis’ article is nothing new. In the 2001 book, Astronomy with Small Telescopes, the then Sky & Telescope columnist, Jay Reynolds Freeman, described his own lap ‘scope, a 6″ f/5 Newtonian reflector, showing that the concept has been alive and well for quite some time now.
Can you think of a more versatile instrument than the 130P?
Date: November 28 2017
Time: 01:25 UT
Seeing: very good, II, excellent transparency, no clouds.
A most successful evening!
I began shortly after midnight seeking a split of Eta Orionis. This system was easily resolved at 271x.
Next, I turned the telescope to 32 Orionis, easily found near Bellatrix; an interesting and very tight pair at 1.3″ but the magnitude differential is about 1.6 (4.2/5.8). Charging the telescope with additional power ( x406), I ran the system from the edge of the eastern field and left it drift through until it reached the western field stop, and repeated this procedure several times. To my delight, it was a fairly easy split!
Next I moved over to 52 Orionis (a tighter, 1″ pair), near the bright winter luminary, Betelgeuse. Though I was monitoring this system for about half an hour, I found it considerably more challenging than 32 Ori. But at 01:15 UT as the system crossed the meridian, a power of 406x was just enough to prize these two nearly equal magnitude stars apart!
Would like to have used a bit higher power with 52 Ori.
Both systems orientated roughly NE to SW.
A glorious sky here!
Will discuss more later today.
Time: 11:00 UT
Last night’s work with the 130P was very encouraging. It shows that this small Newtonian reflector is an excellent double star telescope and capable of resolving pairs down to its theoretical limit.
I encountered a little issue while using the larger 50mm finder. At low and medium power, the larger finder worked well but while using the ultra high powers to tease these stellar pairs apart, I found it to introduce greater vibrations while focusing and that’s not a good thing. I thus switched back to the lighter 6 x 30mm while conducting this work. I just need to place some cardboard or some such under the collar to tighten it up. We live and learn; no sweat.
I am very much enjoying using this excellent grab ‘n’ go telescope. It’s just one sweet little instrument. I feel it gives exceptional value for money and has already paid its way many times over with the wonderful images it has delivered, whether in the open or closed tube configuration.
I see the One Sky Newtonian thread is still going strong on Cloudy Nights, with over 260,000 hits. Very well deserved in my opinion!
The addition of Bob’s knobs to the primary and secondary mirrors of this telescope has been highly satisfactory. I have just ordered another set of these to replace the ones I borrowed from my 8 inch Newtonian. They should be here tomorrow.
The cold snap continues; so I hope to make more observations with the 130P.
A strong northerly air flow has caused the seeing to degrade noticeably from last night ( III–IV), especially with targets located at lower altitudes. That said, some good targets higher up were still well resolved including, Theta Aurigae and Iota Cassiopeiae (271x). The reader will note that these systems are often touted as being ‘tricky’. A consultation of the literature typically (though not always) states that they are “often difficult…. requiring steady nights and high magnification“. This is yet another urban myth. They are accessible much more often than is commonly reported in the popular literature. Why should that bother me? Well, it’s partly about honesty and partly about authority. If I’m buying a book on visual observing, I would expect the author to relay accurate information, and not perpetuate an untruth/exaggeration. Experience is the only panacea.
The telescope is a wonderful outreach instrument. I like to set her up in the evenings when I’m busy with my students. Tonight, a few of them beheld the beauty of a waxing gibbous Moon, either when they arrived or before they left for home. The Baader zoom worked its magic on this target after dark, with lots of “oohs and aaahs,” coming from them as they settled into the telescope for a gander. Because it’s a robust, no–frills instrument, with decent aperture, the 130P makes an awesome outreach telescope. Easy to set up and pack away, you’ll never have to worry about things that go bump in the night. I can’t say the same for other types of ‘scope designs though. ’tis the genius of Newtonianism you see!
Date: November 29 2017
Have I told you the story of mighty Octavius?
Yep; citizen science!
I thank the Lord that I live in a place where the laws of physics are actually obeyed. Can you imagine that! A good telescope with a larger aperture, given fair to good conditions, always proves superior to a significantly smaller one, even if the latter is that little bit better millimetre for millimetre. That said, I find it highly curious that there are some places where the basic laws of optics seem to be violated; such as in the refractor forum of Cloudy Nights. As a scientist trained to think critically, I am given to wonder where the real discrepancy lies; the observer or the environment.
When you’re not thinking like a phallus, you see things objectively, as things really are, not how you want them to be. And the results obtained with Octavius were perfectly in keeping with those garnered by Plotina when assessed against the 90mm apochromat in particular.
The old adage comes to mind; a fool and his money are soon parted.
The new knobs arrived late this evening and were promptly fitted to Octavius’ primary cell. Now all my reflectors are ready to work as they were designed to; right the way through the winter. Yeehaw!
Our Creator designed our bodies to work best while being sober, in our right mind, as it were. And no matter how much we wish to escape reality, no altered plane of perception can improve on this blessed state. I consider it a big no no to observe while under the influence of alcohol or other pharmacological agents. Just one drink alters my state of perception and I have always maintained strict sobriety while observing or making reports from the field. That said, I wonder how many amateur astronomers observe under the influence of alcohol or some other mind altering agent. I believe about one in every seven Americans has problems with alcohol and the incidence is probably higher in many other nations. I know for a fact that some prominent CNers are on record for saying that they enjoy one or two scotches before venturing out of doors with their telescope(s). But if objectivity is to be the goal of the observer, and if the truth is to be valued above all other things, such behaviour most not be condoned. It’s all well and good to enjoy a drink; but not while making observations with the intention to report them. This could contribute to a variety of anomalous results reported by some individuals over the years.
For me, telescopes are instruments to be enjoyed in blessed sobriety, the way our Creator intended it to be.
An Enabling Telescope
Date: November 30 2017
St. Andrew’s Day.
I don’t know about you, but I feel like I’m removing the cobwebs, pulling away the curtains, sweeping up the dust and opening the windows to let the light in. It’s as good a time as any to do so, and I hope that it will have a lasting effect on the hobby. I also hope that it will encourage more individuals to enjoy this wonderful passtime without fear of intimidation from the pretentious prattle of the gearheads.
Another beautiful but cold day here. With the Moon now growing rapidly in brightness, I would like to visit some of the easy, showpiece colour contrast binaries with the 130P this evening.
Could the 130P be your only telescope? I think the answer is definitely *yes*. As I’ve demonstrated, it’s no one trick pony. Indeed, it does virtually everything you’d want to do with a telescope, and with an impressively high level of competence. Indeed, you could have an absolute ball with this instrument for many years. But I am blessed with a few other telescopes that are more powerful (fine 8″f/6 & 12″ f/5 Newtonians); nothing overly flashy, but great workhorses nonetheless.
My transition to Newtonianism has been a worthwhile experience and, truth be told, the last few years of my observing career have been amongst the most productive and happy in my career as a telescopist. It’s been thrilling to see what they can do, especially in regard to high resolution astronomy. It feels right too.
Traditionally, one of the so–called advantages of refractors (and Maks too) pertains to their lack of maintenance. Reflectors, they claim, need some TLC to keep them in tip top condition. Although this is true, I question whether the lack of maintenance is being overplayed and whether it really is an ‘advantage’. For one thing, as I’ve said before, if you do have an accident with a refractor, then you’ll likely have to send it off to someone for professional realignment; which is not an especially pleasant prospect. More importantly though, are we to encourage slothfulness? Is it not good and fitting that the telescopist remain active; both mentally and physically? I dare say, the little bit of TLC needed to keep Newtonian reflectors in good shape is a blessing and not a curse. Personally, I’d rather remain a tinkerer than become bone idle.
Time: 17:30 to 18:00 UT
Seeing: III, remaining a little unsteady, partially cloud covered, bright gibbous Moon rising in the east.
I had a spare half hour this evening so off I sped to some wonderful colour contrast doubles of the winter sky;
Albireo; now in the far west, always a beautiful sight in the telescope. Golden and blue stars wonderfully framed in the generous field offered up by the Baader zoom at 81x
Gamma Delphini: Now sinking into the southwestern sky. A beauty at 81x, with yellow and greenish components.
O1 Cygni; easily located between Delta Cygni and Deneb, this is a lovely sight in any small telescope and sure enough it presented beautifully in the 130P at 20x (Skywatcher 32mm Plossl) but even better at 81x. O1 is a K class star with a marmalade orange hue and just 4′ away lies 30 Cygni, which presents with a greenish tinge to my eye. And to top it all off, the 7th magnitude star SAO 49338 makes for a fetching addition to the field, located as it is just a few arc minutes east of O1 Cygni.
Gamma Andromedae (Almach): a corker at 81x; orange and green riding high in the eastern sky at this time.
Finally, swinging the telescope low into the far western sky, I picked up Rasalgethi in Hercules with its comely red and green components, easily split at 81x.
As I have demonstrated many times over the last few years, Newtonians work very well in sub zero temperatures. Therein lies yet another myth promulgated by those who wish to push refractors on other amateurs; another porky. Indeed I have split some of my tightest pairs with Newtonians in very cold temperatures. What is more, there is no correlation whatsoever between ambient temperature and seeing conditions. One memorable night a few winters back, I obtained a stunning image of the companion to Propus (Eta Geminorum), that ‘little blue pimple’, with Octavius, my 8 inch Newtonian, in freezing temperatures. And truth be told, I have not seen it so well since!
Please don’t cultivate untruths. It’s unfair and discourages amateurs from going out under the starry heaven during cold spells with their reflecting telescopes (and that includes large catadioptrics which were extensively tested by this author a few years back). It pays to remember the work of the Reverend T.W Webb and William F. Denning, who dared to venture out with their large reflectors (with no fans either) during cold winter nights to bring the beauty of the sky into your warm and comfortable living rooms.
The Newtonian reflector reigns supreme over all other telescope designs. And this 130P has earned a distinguished place in my collection. It will remain my grab ‘n’ go telescope of choice in the future. It’s modest cost will allow many more beginning amateurs to cut their teeth in this wonderful hobby, with its excellent optics and great portability, but it’s powerful enough to engage seasoned observers as well. Whatever your preferred targets for observation are; Moon, planets, double stars, widefield and high magnification deep sky, the 130P will not disappoint. It also makes a wonderful daytime telescope for nature studies. I commend SkyWatcher for bringing this amazing instrument to market and wish them every success in the future.
Thank you for reading.