115 replies to this topic

[Jon Isaacs]

 

I tried my 127/1500 mak at 250 magnification and it was underwhelming. Dim, it didnt "pop" like my 80mm apo/ed. Didn't bother increasing the zoom as I didn't feel it would improve image.

 

Historically, Maks have been notorious for slow cooling and thermal issues.  But that has changed.  People use Reflectix to insulate their SCTs and Maks, it stabilizes the scope and allows for quality views without waiting for the scope to reach thermal equilibrium with the outside air, it is in thermal equilibrium with itself.

 

This is a custom 8 inch SCT insulated with Reflectix. 

 

 

Jon

[Japetus Eye]

I have both 80 mm and 4 inch apo/ed refractors.  At the same magnification, the 4 inch is 60% brighter.  That is easy to see but also allows one to use greater magnification at the same brightness.  At planetary magnifications in scopes of these apertures, brightness is an important part of the equation because the exit pupils are small, the images are dim.  

 

The greater resolution and contrast of the larger scope is an important factor but brightness also plays a role.

 

Jon

It's out of the question: the two cm in favor of 4" make it almost 60% brighter, but the difference, which numerically may seem a lot, in my opinion, is not something too relevant in the observation in the comparison, or at least, that's how I see it. That's why I qualify the "noticeable" thing.

 

Comparing the SW 100ED and the SV503 80ED, for me the qualitative difference is more remarkable than the quantitative one in terms of the perception of fine and subtle details, for example on planetary surfaces or on the Moon. I must say that I live under suburban skies and I don't really tend to observe many deep sky objects where the brightness factor can be more relevant. Even so, I have not been able to "isolate" that factor observationally with the typical brighter nebular objects accessible from my skies.

 

The difference in luminosity (light gathering capacity) should be very evident when comparing, for example, an 8" reflector with a 100ED one, although the optical quality of the latter allows for slightly better contrasted or sharper views. That's what I mean. At least for observers who are not as advanced or trained, like myself or (I assume) our fellow topic starter...

[Mr. Mike]

20mm is 20mm. Its definitely something.  More light grasp.  For me, I'd have to go a little larger to upgrade as in a 110mm or a 120mm, maybe.  But an 80mm to a 100m will be a tangible upgrade in photon absorption.  Not night and day, but tangible.

Edited by Mr. Mike, 06 February 2025 - 08:25 PM.

[Jon Isaacs]

It's out of the question: the two cm in favor of 4" make it almost 60% brighter, but the difference, which numerically may seem a lot, in my opinion, is not something too relevant in the observation in the comparison, or at least, that's how I see it. That's why I qualify the "noticeable" thing.

 

Comparing the SW 100ED and the SV503 80ED, for me the qualitative difference is more remarkable than the quantitative one in terms of the perception of fine and subtle details, for example on planetary surfaces or on the Moon. I must say that I live under suburban skies and I don't really tend to observe many deep sky objects where the brightness factor can be more relevant. Even so, I have not been able to "isolate" that factor observationally with the typical brighter nebular objects accessible from my skies.

 

The difference in luminosity (light gathering capacity) should be very evident when comparing, for example, an 8" reflector with a 100ED one, although the optical quality of the latter allows for slightly better contrasted or sharper views. That's what I mean. At least for observers who are not as advanced or trained, like myself or (I assume) our fellow topic starter...

 

When you are comparing the SW100ED with the SV503 80ED, you are comparing a scope with greater light grasp and optical quality with a smaller scope poor correction. The larger scope has two advantages. The planets, at planetary magnifications in scopes this size are dim, the added light grasp, it is helpful.  I see it when comparing an 80mm at 200x to a 102mm at 200x.  A 100mm scope is as bright at 200x as an 80mm is at 160x.  

 

In 2007, I was given the very first AT-102ED to review.  This is a FPL-51 class doublet similar to your Svbony.  At that the time, I had an excellent William Optics 80mm F/7 FPL-53 doublet. The 80mm had the superior optics, no chromatic aberration etc.  But the AT-102ED provided the better planetary views.  That is because aperture buys, contrast, resolution and image brightness.

 

I observe frequently under dark skies with scopes of all apertures. A 16 inch captures 64% more light than a 12.5 inch.  Very similar to the 61% more light that a 4 inch captures over an 80mm. The differences is quite apparent.. 

 

Jon

[maniack]

I observe frequently under dark skies with scopes of all apertures. A 16 inch captures 64% more light than a 12.5 inch.  Very similar to the 61% more light that a 4 inch captures over an 80mm. The differences is quite apparent.. 

 

Jon

Even at home the difference between my AT72EDII and SV48p (90mm) is quite significant on the Pleiades and panning around Orion at low power.

[radiofm74]

I think that a reflex has developed of saying to any beginner asking for a new scope "unless you jump up to 8" of aperture it's not worth it". I disagree. An 8" Dob is a great scope, as is a C8. Each also comes with its set of problems and limitations, like any scope. A good 4" ED doublet is a stone-cold classic, a lifer and will invariably become one of your most used scopes, especially if you live under the Bortle 9 of a metropolis, and even after you'll have bought larger apertures. At least, that's my experience.

 

One thing that's almost never mentioned when talking about "beginner scopes" is that a good refractor (emphasis on "good") is the zen-est telescope there is. No collimation headaches, no cooldown to speak of, just movingly beautiful image quality, especially on stars, clusters, the Moon and planets. A good 3" is already a joy to use, and may surprise you if you take it to darker skies with what it can show. A good 4" (such as the Skywatcher 100ED you've mentioned) is one significant step up in capability in every department.

 

I live in Milano (B9) with a Vixen ED102 and a C8. I love the C8, and of course it can go deeper on good nights. But unless seeing is great, I'll take the Vixen. On doubles, lunar, planetary it is simply an amazing telescope. And it's a very capable DSO telescope. In the city, it will not be far behind the C8, although the difference in aperture is felt. Under darker skies, its range is very broad and while I'll rather take a C8 or R200SS for nebulae, galaxies, and globulars, the 4" is a fabulous all-rounder, the one scope that guarantees an entirely headache-free night, and my first pick for open clusters. In November I explored Cassiopeia in three nights with it, and those were three of the best nights I've had out with a telescope.

 

So, while an 8-incher would doubtless be more complementary to the 3" ED scope you already have, let no-one tell you that going up to a 4" ED doublet would be no upgrade 

[PKDfan]

Hi
I was wondering if anyone has an 80mm apo and also a 100mm and if there is a big, noticable difference.

( I have looked and on numerous stores, they have all dropped the price on this skywatcher. Does this usually happen? Anyone know why? As this happened with starsense a few months ago. It was £200 for a few weeks and now it is back to £280)

I have a 80/560mm apo from starfield and have just seen Skywatcher Evostar 100 ED DS Pro on sale with a focal reducer, 2 inch diagonal, rings and mounting plate, a finderscope, 28mm eyepiece, reduced from £945 ($1179 us dollars) to £729 ($910 usd)

This is a large scope 900mm fl, f9 but has a focal reducer also.

I have been wanting a new scope, was thinking a 150mm achro, but now this has come up at around the same price.

Would you guys get a 100mm if you had an 80mm? Also, side question, is a 100mm apo better than a 150mm achro ( im guessing no as for dso, the achro wins)

Thank you everyone

Hi Arkade !

Sky-Watchers sale right now IS the time to buy and as to why the cut rate price perhaps they didn't move enough during the holidays ?

I have 62mm & 100mm (Evolux & Evostar) and love both but two wildly different focal lengths.

My two samples are exemplary so buying one now with a massive discount is a no-brainer.

If i could buy a 150 Evostar at their sale price i would instantly.

IMO SW is kind of an underrated company at least with Evostar Espirit and the North American loss of the Evolux line is a crying shame.

As for a achro or apo whats your favourite targets ? Planets moon sun or DSOs type stuff ?

Either way a fully solved chromatic solution and a long proven life equals a can't go wrong choice.

My 100ED was my very best optical purchase bar none.


80mm has one third less aperture illumination so my two apos have a much more significant aperture differential so was easy to choose but if i had an 80mm first then choosing would be harder.

100mm is right at the easy to setup point and requires a less robust mount than a 150mm class scope.

I use EQM-35 for the 100ED.

Good Luck with this very difficult choice !


CSS
Lance

[Astro-Remete]

+1 for the 4"APO, I also live in a big city (Budapest), I have a Bortle8-9. I sold the C8 and left with the ES102CF. Maybe I'll move on to an Askar140.

[doyers017]

It would be a noticeable, but not dramatic improvement.

 

Personally if I had an 80mm, I would strongly consider getting the 100mm (and selling the 80mm), but that extra aperture will help when you go to dark sites, not too much at home.

[radiofm74]

It would be a noticeable, but not dramatic improvement.

 

Personally if I had an 80mm, I would strongly consider getting the 100mm (and selling the 80mm), but that extra aperture will help when you go to dark sites, not too much at home.

Agreed that unless there is an interest in keeping the 80 (e.g. it's a good focal length for imaging), I'd let it go.

 

I disagree that the added aperture would not help much in the city. In my 4", I can split significantly closer doubles, and see considerably more lunar and planetary detail, while pushing magnification from ≈160-180x to ≈230x. This, leaving aside DSOs, for which the added light grasp undoubtedly helps. 

[dnrmilspec]

There is another stubbornly perpetuated myth in this thread.  That is the notion that darker skies favor larger scopes and brighter skies eliminate this advantage. Larger scopes outperform smaller ones regardless of sky glow.  But more to the point, worrying about the difference between a 3" and a 4" is not worth the time.

 

The key to understanding telescope use under differing sky conditions is best understood by first selecting the appropriate thing to go looking for.  There are objects that are more pleasing under dark skies and some that don't matter at all. And some that disappear entirely.   So if you are under a street light in the center of Manhattan, looking for galaxies, you are looking for the wrong thing not looking through it. 

 

I have both 80mm and a 102mm scopes.  The 4" scopes outperform the smaller ones all of the time.  But the difference depends on the target to a great extent.  We can't forget that quality of the optics being equal, the 4" scope will allow significantly more magnification than the 3" will.  This favors a significant number of targets.  Then, when we pack up and go to the woods, the aperture of the 4" still favors more objects, but for a different reason.

[Inkie]

Agree fully.  Larger aperture = more resolution (ability to separate two close-set objects of similar brightness, so double-stars as an example). Larger aperture = more photon-gathering, so dimmer objects can be seen than in the smaller aperture being compared. Both apertures will be affected by incident and ambient light, or the lack of it.

[PalomarJack]

I am starting to think the cheapest and best idea is just getting an 8 or 10 inch dob. As other options end up near a thousand pound and would require new mount.

I have been going back and fourth, a 150 achro, a bigger apo, just keep changing my mind.

I agree, a dob. I think i should be sensible and patient. Enjoy my 80mm apo, get most out of my 130/650 newt and upgrade once i really need to

Good direction. To be honest you would be wasting money on such a small upgrade. To see any significant change you have to double the aperture. That's double the resolution and four times the light power. And if it's from a top quality refractor to top quality reflector add another 10% to the aperture. What this comes down to is 8" (200mm). Now, keep in mind you can rationalize yourself up to a 24" and into the poorhouse from here, too. Also keep in mind that the larger aperture will get you more light, but it also gets you a smaller field. And to get some of that field of view back you are looking at very expensive eyepieces. You also have to transport this thing. See what I mean when I mention poorhouse?

 

So my suggestion is 8", 10" tops if you can transport it easily. Don't sell the 80mm, you are familiar with it and it will make an excellent "travel 'scope" to take on holiday. Put a 45* erecting diagonal on it and you are way, way past those nasty coin-op binoculars seen at tourist traps, although a good pair of 42mm or 50mm binos would be better at times. If it is about the same f/ratio as the refractor, you can use your existing eyepiece battery with about the same "expectation of performance" and delay buying new eyepieces. Another financial plus!

 

On that subject, if you don't have them, consider good quality binos, too. Not less than 50mm. If you are young you can use 7X for 3.5x per inch. If not, get 8X for the slightly smaller exit pupils. Too low of power and you actually lose effective aperture, same as a telescope.

 

Hope this helps you, and others... clear skies... someday.

[BKBrown]

I own a number of refractors ranging from 66mm to 150mm, but the best bang for my buck that I ever bought is the Skywatcher 100ED Pro (now Evostar). It was the first scope I acquired on coming back to astronomy in a big way and I picked it up for $999; and it came with a perfectly serviceable equatorial tracking mount! Ah, those were the days. That scope has continued to grow with me over the years as I gained greater proficiency in my visual observing and imaging skills, and it has proven to be endlessly upgradeable and versatile. First I swapped out the stock focuser for a MoonLite CF2 (now no longer available ), followed soon after by a mount upgrade (the Orion Sirius, essentially a SW HEQ5-P), and superior mounting hardware from ADM and Parallax instruments (the saddle and rings). Next came better finders, external camera mounts, a 2" tripod for the mount bought second hand, accessory trays bought or fabricated at home, then guide scopes, dew strips and strip controllers, an ASIair control hub for AP, and an ever evolving selection of terrific eyepieces. The image below is where I am with this scope after 15 awesome years under the sky...and it just keeps getting better. 

 

 

So step back and think about what you want to do now, and where you might want to go in the future. Find a scope with great optics, first and foremost, and know that any perceived deficiencies or shortcomings can be resolved with aftermarket accessory items. You don't have to have everything right now, you can let yourself grow along with your instrument. But shoot for that great optic that will support your needs. I consider my SW 100ED Pro to be a forever scope, right alongside my TEC 140ED. It is light, easy to mount, cools down quickly (it is a doublet), and has superb color correction. I can recommend this gem of a telescope without hesitation 

 

Clear Skies,

Brian 

Edited by BKBrown, 17 February 2025 - 10:41 PM.

[PKDfan]

I own a number of refractors ranging from 66mm to 150mm, but the best bang for my buck that I ever bought is the Skywatcher 100ED Pro (now Evostar). It was the first scope I acquired on coming back to astronomy in a big way and I picked it up for $999; and it came with a perfectly serviceable equatorial tracking mount! Ah, those were the days. That scope has continued to grow with me over the years as I gained greater proficiency in my visual observing and imaging skills, and it has proven to be endlessly upgradeable and versatile. First I swapped out the stock focuser for a MoonLite CF2 (now no longer available ), followed soon after by a mount upgrade (the Orion Sirius, essentially a SW HEQ5-P), and superior mounting hardware from ADM and Parallax instruments (the saddle and rings). Next came better finders, external camera mounts, a 2" tripod for the mount bought second hand, accessory trays bought or fabricated at home, then guide scopes, dew strips and strip controllers, an ASIair control hub for AP, and an ever evolving selection of terrific eyepieces. The image below is where I am with this scope after 15 awesome years under the sky...and it just keeps getting better.

IMG_4112_a.JPG

So step back and think about what you want to do now, and where you might want to go in the future. Find a scope with great optics, first and foremost, and know that any perceived deficiencies or shortcomings can be resolved with aftermarket accessory items. You don't have to have everything right now, you can let yourself grow along with your instrument. But shoot for that great optic that will support your needs. I consider my SW 100ED Pro to be a forever scope, right alongside my TEC 140ED. It is light, easy to mount, cools down quickly (it is a doublet), and has superb color correction. I can recommend this gem of a telescope without hesitation

Clear Skies,
Brian

It is absolutely Gorgeous BKBrown !!


Mine is in a bit of a frump and looking rather limp in comparison.

I'm so glad to hear its got the rightstuff too as Figure be everything.



CSS
Lance

[Spaceman 56]

I have a Stellarvue 80mm and also a Stellarvue SVX102.

 

the 102 is better for visual than the 80mm. 

 

but if I was upgrading from an 80mm for visual, I would look for something much bigger than a 4 inch.

 

I would want 6 inch at least, and probably 8 inches, or even more.

[dnrmilspec]

+2 for the SW 100ED.  It is a great scope in every respect. 

[PKDfan]

+2 for the SW 100ED. It is a great scope in every respect.

Hi dnrmilspec !

I am flummoxed by peoples perception that the 100ED is overpriced ???!???

Its simply ludicrousness times 1000.

Best value in telescopes RIGHT NOW. Bar none.

Mine meets Taka level fidelity and dare i say it...is even better.


Sale of a lifetime.


CSS
Lance

[dnrmilspec]

Hi dnrmilspec !

I am flummoxed by peoples perception that the 100ED is overpriced ???!???

Its simply ludicrousness times 1000.

Best value in telescopes RIGHT NOW. Bar none.

Mine meets Taka level fidelity and dare i say it...is even better.


Sale of a lifetime.


CSS
Lance

I absolutely agree.  

 

Experienced folks often look past this one because they don't read the tech specs.  It is not your average 4" ED scope.  And for a beginner it is an even greater bargain.  IT comes with everything they need to put it on a mount and go including 2 very nice eyepieces, a dielectric diagonal, rings and place, and an 8X50 RACI finder.  Its on sale now at our sponsor for $849.00!  That is a stunning price.  The diagonal alone  is worth $150 of that. Rings  and it comes in a really nice fitted aluminum case.  Just now seeing that price, I may buy another one.  

 

Most people just cruising the ads miss a very important point.  This refractor, in addition to being F9, has FPL-53 glass.  That is just about as good as a doublet can get.  Color performance of mine is every bit as good as my faster 5" triplet.  Perhaps better.  This scope is a planet killer as some people call it. Globs and Double stars are about as good as it gets for a 4" scope.   Still, with the supplied 2" diagonal and a decent upgraded eyepiece it will give pleasingly wide views.  Even with the supplied one you can get 1.25 degree FOV.  Add a nice mount to this scope and you have one serious bargain for not a lot of money.  And oh by the way, the OTA is significantly lighter than many making it easier to mount at this focal length.  If I had any complaint at all it is that some have reported issues with the focuser.  I have not experienced this and adjustment is easy to do.  And did I point out FPL-53 glass?

 

How is that for a rave review?

[PKDfan]

I absolutely agree.

Experienced folks often look past this one because they don't read the tech specs. It is not your average 4" ED scope. And for a beginner it is an even greater bargain. IT comes with everything they need to put it on a mount and go including 2 very nice eyepieces, a dielectric diagonal, rings and place, and an 8X50 RACI finder. Its on sale now at our sponsor for $849.00! That is a stunning price. The diagonal alone is worth $150 of that. Rings and it comes in a really nice fitted aluminum case. Just now seeing that price, I may buy another one.

Most people just cruising the ads miss a very important point. This refractor, in addition to being F9, has FPL-53 glass. That is just about as good as a doublet can get. Color performance of mine is every bit as good as my faster 5" triplet. Perhaps better. This scope is a planet killer as some people call it. Globs and Double stars are about as good as it gets for a 4" scope. Still, with the supplied 2" diagonal and a decent upgraded eyepiece it will give pleasingly wide views. Even with the supplied one you can get 1.25 degree FOV. Add a nice mount to this scope and you have one serious bargain for not a lot of money. And oh by the way, the OTA is significantly lighter than many making it easier to mount at this focal length. If I had any complaint at all it is that some have reported issues with the focuser. I have not experienced this and adjustment is easy to do. And did I point out FPL-53 glass?

How is that for a rave review?

SPOT ON !!

I'll try and one up ya dnrmilspec !!

This scope has given me near one Thousand rille power and is why my life afterwards was forever different.

My Mars oct 16 2022 at 270X is the reason i breathe erratically.

The Double Cluster at B1 45X & Alfred Naglers masterpiece as i determined each their spectral classifications. All the stars a uniquely beautiful hue.

That same location and nite Sagitarious and Scorpios various treasures M17 the swam swimming majestically head held high M20 Triffid unbalanced luminosity mind altering contrast are all a wonderful and indelible stain as my memories come fast, how these islands of floating brilliance amid pinpricks of sparkly imagination sprinkled throughout again and time again each memory with thanks to Mr. Naglers 20mm T2.

Thank You Al !!!

I'm going to try and astonish the community over the next few years as i take my landscape photography skills to the sky and plumb the depths of it especially on the moon.

Give SW some free publicity as thanks for two superlative telescopes, world class in every regard, except for the darn evolux blackening issue, that atomic force irradiation scatter i'm getting from it has grown intolerable so will be fixed very soon.

Good to have a serious project on the go again.

I'd really like to get an adapter made to mount the Evolux as the CW on my EQM-35 and use both at the same time.


Cheers from warming Edmonton !!



Lance
CSS
Edited grammar

Edited by PKDfan, 19 February 2025 - 11:48 AM.

[Jay_Reynolds_Freeman]

Other things being equal, any increase in aperture will bring benefits: Going from 80 mm to 100 mm gains about half a magnitude in the faintest stars you can see and provides a 25 percent increase in resolving power.

 

On the other hand, things are not always equal. Even if the optics and mechanical construction are of the same design and quality, a 100 mm instrument will have greater weight, bulk and cost than an 80 mm unit, and will require more fuss to transport and set up. You must also consider how you use the telescope: If your 80 mm is for grab-and-go, will the larger instrument also be satisfactory?

 

Amateur astronomers who have a decent 80 to 100 mm refractor available often consider getting a much larger instrument, possibly of a less expensive design, as an alternative. Dobson-mounted Newtonians and Schmidt-Cassegrains are common choices, but it depends on what you yourself can afford, and on what you are able to transport, set up and use.

 

Clear sky ...

[Arkade]

Other things being equal, any increase in aperture will bring benefits: Going from 80 mm to 100 mm gains about half a magnitude in the faintest stars you can see and provides a 25 percent increase in resolving power.

On the other hand, things are not always equal. Even if the optics and mechanical construction are of the same design and quality, a 100 mm instrument will have greater weight, bulk and cost than an 80 mm unit, and will require more fuss to transport and set up. You must also consider how you use the telescope: If your 80 mm is for grab-and-go, will the larger instrument also be satisfactory?

Amateur astronomers who have a decent 80 to 100 mm refractor available often consider getting a much larger instrument, possibly of a less expensive design, as an alternative. Dobson-mounted Newtonians and Schmidt-Cassegrains are common choices, but it depends on what you yourself can afford, and on what you are able to transport, set up and use.

Clear sky ...

Thank you for the advice. I am starting to realise your point. Would you think a 150/750 achro is large enough or still an 8/10 dob?

[Jay_Reynolds_Freeman]

Thank you for the advice. I am starting to realise your point. Would you think a 150/750 achro is large enough or still an 8/10 dob?

Short answer: I would go for the Dobson. Details follow ...

 

A conventional achromat of 150 mm aperture and 750 mm focal length would have chromatic aberration that might warrant the description "psychedelic". You would probably find it useful only for deep-sky observation at very low magnifications, probably no more than 60x; that is, it would make a decent rich-field telescope, but would not be good for much else. It would also be a bit cumbersome for grab-and-go, though less so than an 8- or 10-inch Dobson-mounted Newtonian.

 

A decently-made 8- or 10-inch Dobson would blow a 150/750 conventional achromat out of the water for almost any kind of visual astronomy, with the possible exception of extremely wide-field views at very low power, where the diameter of the focuser (presumably two inches) would limit the field of view.

 

Note that if you already have an 80 mm refractor, it probably makes a decent rich-field telescope in its own right.

[Tony Flanders]

A decently-made 8- or 10-inch Dobson would blow a 150/750 conventional achromat out of the water for almost any kind of visual astronomy, with the possible exception of extremely wide-field views at very low power, where the diameter of the focuser (presumably two inches) would limit the field of view.

I might add that the Dob will be faster to set up and easier to use. And once you factor in an appropriate mount for the 150-mm achromat, probably also easier to carry and significantly cheaper. And unlike any refractor, almost immune to dew.

[Jon Isaacs]

Experienced folks often look past this one because they don't read the tech specs.  It is not your average 4" ED scope.  And for a beginner it is an even greater bargain.  IT comes with everything they need to put it on a mount and go including 2 very nice eyepieces, a dielectric diagonal, rings and place, and an 8X50 RACI finder.  Its on sale now at our sponsor for $849.00!

 

 

At $849, it is a deal.  But it hasn't been $849 for a long, long time. It is nice to see that Skywatcher has returned to a more reasonable pricing on these.  

 

Optically they are very good but their long focal length limits their useful for someone like me who uses a 4 inch refractor for both backyard planetary as well as dark sky, deep sky/wide field.  Mechanically, they are adequate but not of the build quality of scopes like the Astro-Techs.  

 

The finderscope is listed as an Right Angle finder rather than an RACI and historically, the finder has been an RA. These are OK if they are mounted with the eyepiece vertical because the image is correct top to bottom but flipped left to right.  If the finder is at an angle then they are problematic because the field is flipped at that angle.

 

I would call the eyepieces, usable, the diagonal, adequate..  If I remember correctly, for a number of years, these were $749 and would occasionally go on sale for $649.   At $1255, that was too much. 

 

It is nice to see this price reduction, hopefully it is not temporary. The Evostar 80mm and 120mm are also reduced, the 80 mm is $649, and the 120mm is $1799.  

 

The elephant in the room is whether or not, Skywatcher has changed the objectives.  Now that they are no longer providing the glass types, it is possible that these are new scopes with FPL-51 class objectives.  I doubt that but it is possible and would explain the return to more reasonable pricing.

 

Jon