897 replies to this topic

[CHASLX200]

Okay another session with the scope under the belt, under much better seeing conditions albeit worse transparency.  The occasion was the de-consecration of OFLI's home observing field in Sonoma.  The property is being sold, and this was our final session from the site.  12 years.  Wow.  Tempus fugit.

 

It was fun sharing the big Skywatcher with the others.  Targets primarily were planets (Mars, Saturn and Jupiter),  a couple of bright summer globulars, easy double stars and an opportunity to re-evaluate color correction and the star test (unfiltered this time) under better conditions.

 

The best news is that the optic appears to be centered with no evidence of wedge or similar errors.  Star testing pretty much corroborated my earlier results under poorer seeing - an adequate but not fantastic optic.  Better'n 1/4 wave but just at or even a little shy of 1/5 wave, and a bit over-corrected.  Smooth enough but not super smooth.

 

I would put seeing last night around Pickering 7.  For planets that were better placed above the slop (Jupiter early in the session and Saturn following) the scope did a credible job.  In keeping with being a good but not great optic, usefulness in good seeing started to break down pretty early as magnification was ramped up.  At 25x per inch (150x) a very slight deterioration of image sharpness entered the equation, though more detail was seen on both gas giants despite the slight softening.  At 33x per inch (200x) things got pretty soft frankly to the point where the optic, not seeing, was doing more harm to the image than magnification was producing additional detail.  As is typical Saturn remained a little "tighter" than Jupiter at this magnification level, but at 33x per inch I was definitely trading image quality for scale.  While I'm not exactly disappointed, and my intended use of this instrument (more on this in a second) isn't affected by these results, this would not be my first choice in refractors for a planetary aficionado.  IMO the ES 127ED is the better bet, having now used four samples of that scope and been generally impressed with planetary performance up to about 40x per inch in good seeing.  But I digress.

 

My intended use of this scope is primarily deep sky, wide field observing, specifically in the context of guiding mounted binoculars to target regions using a GLP.  It replaces a United Optics 6" f/5.9 achromat in this role.  For this purpose it'll be a fun scope, with one qualification.  The qualification being that the case is ridiculously huge (oversized).  So much so that it makes it patently unpleasant to load, unload and transport the scope.  Figure the scope in its case takes up 4x the cargo area in a vehicle as the 6" f/5.9 achromat in a padded lighting stand bag (soft case).  I am noodling sourcing a padded carry bag for the OTA from Pacific Designs and reserving the metal case for storage.

 

I spent a good deal of time working on the focuser earlier in the day yesterday.  I still cannot determine what exactly is making the irregular "clicking" as the draw tube is racked in and out.  I did manage to reduce the amplitude of the irregularity by carefully paralellizing the roller with the draw tube flat and messing with tension "teeter-totter" screws, as well as four point tilt (the little rubber o-rings at each corner of the roller assembly attachment plate are pretty cool/clever.  Next project is to use a sharpening stone to flatten the draw tube flat.  I definitely need a replacement focuser, and would like a stock replacement, since even tuned carefully this one in current condition is a huge let down at any but minimal magnification.

 

Color correction.  Hmm...a little better in better seeing unsurprisingly.  But still plenty colorful on our old friend Vega.  Definitely deep blue tinging violet CA on that star even at lower magnification.  The issue of imperfect correction was made even more obvious by head to head comparison with a nearby FS-128.  Ignorance is bliss.    200x on Vega is dispels any notion or pretension about this being an APO.  On the other hand, flase color on Saturn was hard to find.  But False color on Juiter was there albeit pretty subtle even at higher magnification.  All by itself with no better reference would likely leave the owner happy with the amount of false color.  Coming from a fast achromat, I'm tickled pink with the color correction compared to the achromat I replaced with this scope.

 

More to come...

 

- Jim

Well if the image is breaking down at powers below 50x per inch i am sure i won't be happy with that. With my viewing tatse the scope would live at 60 to 80x per inch most of the time and be pushed to 100x per inch.  50x per inch is nothing for a super good 6" scope in my seeing.  I know for a fact i would notice ho hum optics right off the bat. So if tnis scope can't give a true sharp image at 400 to 450x i would send it back in a flash as i live at power above 60x per inch for planets and the moon..

 

Maybe a better lens in the $4k price range would be a better hit for a 6" as i would not deal with a sub par optic at the 2K price range. I am hoping the one you got was below the normal that these scopes can do and maybe they vary from OTA to OTA.  My AT102ED just keeps humming past 80x per inch and gives very sharp views.  I have kept the AT 102ED for 8 months so that should tell everyone something.

Edited by CHASLX200, 12 August 2018 - 03:56 PM.

[jay.i]

Chas, just get the AT152ED, upgrade to a G11, and tell us how good it is. We need to know!

 

Jim, I am a little concerned that the scope breaks down at 25-30x per inch. I would expect it to hit 40-50x/inch. Is it possible the optics or focuser need to be collimated? I mean... 25x per inch is the highest usable magnification before image breakdown, I'll get a better image from my TMB105 at 150x than I would with the SW150ED. Sure the 150 will be brighter but the TMB will have less CA and SA and improved sharpness. A 6" refractor for deep sky sounds great, but if there's almost no point on using it for planets when compared to a great 4" triplet (or fluorite doublet) then I don't know how attractive it really is... as someone who spends more time with planets and the moon due to light pollution at home, it would need to be great for both planetary/lunar and DSO to get my vote. Based on what I've read from the other reports, it seems that your lens may be underperforming.

[CHASLX200]

Chas, just get the AT152ED, upgrade to a G11, and tell us how good it is. We need to know!

 

Jim, I am a little concerned that the scope breaks down at 25-30x per inch. I would expect it to hit 40-50x/inch. Is it possible the optics or focuser need to be collimated? I mean... 25x per inch is the highest usable magnification before image breakdown, I'll get a better image from my TMB105 at 150x than I would with the SW150ED. Sure the 150 will be brighter but the TMB will have less CA and SA and improved sharpness. A 6" refractor for deep sky sounds great, but if there's almost no point on using it for planets when compared to a great 4" triplet (or fluorite doublet) then I don't know how attractive it really is... as someone who spends more time with planets and the moon due to light pollution at home, it would need to be great for both planetary/lunar and DSO to get my vote. Based on what I've read from the other reports, it seems that your lens may be underperforming.

I would never buy a front heavy triplet that has to be mounted way down on the saddle. Been there done that with a 6 F/9 AP and a AT 130 EDT and just way too heavy. Looks like i may have to find a used FS128.

Edited by CHASLX200, 12 August 2018 - 04:59 PM.

[Bomber Bob]

Okay all y'all, Jim kept a scope that I would've sent back.  So, it's probably not a good sample.  If you're debating APM vs. S-W, either buy the APM that has lots of glowing user reports, or wait until more S-W owner posts come in.

 

I sure wouldn't keep a $2500 refractor that goes soft at 30x per inch!

Edited by Bomber Bob, 12 August 2018 - 05:02 PM.

[CHASLX200]

Jim, your results are so different than ours. I wouldn’t be satisfied based on what you shared and I’m quite dubious about that sample based on what you’re saying. Also, just a few things I’d like to add and and I’m not aiming this specifically at you. I see it in the forums alot. There are a number of people who simply look at images in Suiters book and try to call out a wavefront and there are several serious problems with this. We even have people here on CN who think all their SCT’s are 1/8th wave because of this. That’s absurd. Honestly, I’d rather get more specific details about the star-test and what you’re seeing in it and what the reasons may be. Also, you’re seeing over-correction? That’s bizarre, particularly for a refractor that’s color corrected in the manner this is. I’d like to know more about your thoughts on the tube acclimating as well. The other thing is the Moon. For casual glances at the Moon, I get your point, but the fact that the Moon is bright does not negate the factors needed for discerning and resolving fine, intricate details. For example, the fine craterlets on the top of the lunar domes near Hortensius and Milichius. Most people glancing at the Moon would not be paying specific attention to why they would or wouldn’t be seeing these features which have to be properly highlighted after first quarter. Its like an observer who who has a 5” refractor and someone who has a 60mm refractor and everyone looking through the 60mm says... hey it looks great in this little scope too. Yea, but what are you looking at specially? What are you trying to discern or resolve? There’s a huge difference. 

I wished you would sell me that one you used.  I expect SCT's to go soft past 30x per inch but not a good Newt or ED.

[Daniel Mounsey]

Jim, I wouldn’t be satisfied based on what you shared and I’m quite dubious about that sample based on what you’re saying. Also, just a few things I’d like to add and and I’m not aiming this specifically at you. I see it in the forums alot. There are a number of people who simply look at images in Suiters book and try to call out a wavefront and there are several serious problems with this. We even have people here on CN who think all their SCT’s are 1/8th wave because of this. That’s absurd. Honestly, I’d rather get more specific details about the star-test and what you’re seeing in it and what the reasons may be. Also, you’re seeing over-correction? That’s bizarre, particularly for a refractor that’s color corrected in the manner this is. I’d like to know more about your thoughts on the tube acclimating as well. The other thing is the Moon. For casual glances at the Moon, I get your point, but the fact that the Moon is bright does not negate the factors needed for discerning and resolving fine, intricate details. For example, the fine craterlets on the top of the lunar domes near Hortensius and Milichius. Most people glancing at the Moon would not be paying specific attention to why they would or wouldn’t be seeing these features which have to be properly highlighted after first quarter. Its like an observer who who has a 5” refractor and someone who has a 60mm refractor and everyone looking through the 60mm says... hey it looks great in this little scope too. Yea, but what are you looking at specially? What are you trying to discern or resolve? There’s a huge difference. I’ve even seen differences with eyepieces that affect the subtle features of the Moon.

Edited by Daniel Mounsey, 12 August 2018 - 05:37 PM.

[jrbarnett]

At 33x per inch (200x) things got pretty soft frankly to the point where the optic, not seeing, was doing more harm to the image than magnification was producing additional detail.

 

Thanks for the report Jim!  Yikes!  That is sub-par for a 6" refractor - regardless of design, glass type, or country of origin.  My beat up old 1971 Criterion RV-6 F8 Newtonian is sharp at 40x per inch.  My APM is sharp at 80x per inch.  I know the impact of local conditions, but at the P-7 seeing you reported... I hope it can be attributed to the post-shipping repairs, and other mechanical factors.

Yep.  My old 10" f/4.7 Dob with Synta optics was there as well, now owned by a club mate.  It definitely put up sharper high magnification images of Mars than the ED150 last night.

 

Like I said, this particular unit  would not be my first choice for planets if I were an avid planetary observer.  But it's a nice high contrast deep sky scope; no obstructions, relatively smooth very clean optics - good for the combination of wide and deep.  Definitely smoother optics than the United Optics achromat it replaced and the absence of so much false color also helps when something bright is in the FOV, which is a big plus.

 

I don't think this level of quality is uncharacteristic of 1670 Euro 6" ED doublet.  Remember this scope costs about the same as the APM-UO optical group alone.  In the European market before APM cut its price to 2500 Euros in response to the Skywatcher introduction, this scope was about HALF the price of the base APM with the cheap focuser.  I really dislike the base UO focuser too.  The one that came on the 115mm prototype that I tested for a US dealer looking to pick up the line was non-functional when it arrived (direct ship from China to me for testing).  The UP scope was much better packed than this SW, and the fine focus knob was protected with a plastic cap over it, and still it didn't function.

 

You'd think focusers are pretty simple things.  There's no reason a Chinese manufacturer shouldn't be able to mass produce focusers that are as good as the Starlight units.  But alas, that's not yet the case.  I actually like the simply Synta Crayford for visual use.  It's simple and lightweight.  But in my case the unit I received punched a hole in the lid of the hard case in transit and now I'm wrangling for a replacement.  There's a thin chance (very thin) that a more precise focuser without clicks and seeming flat spots would alter my visual impressions of the scope.  Achieving best focus isn't especially easy with the focuser in this condition, but I'm relatively confident that even with a good focuser the optics will be just average just as they appear to be in subjective use with this focuser.

 

Best,

 

Jim  

Edited by jrbarnett, 12 August 2018 - 09:01 PM.

[jrbarnett]

Jim, I wouldn’t be satisfied based on what you shared and I’m quite dubious about that sample based on what you’re saying. Also, just a few things I’d like to add and and I’m not aiming this specifically at you. I see it in the forums alot. There are a number of people who simply look at images in Suiters book and try to call out a wavefront and there are several serious problems with this. We even have people here on CN who think all their SCT’s are 1/8th wave because of this. That’s absurd. Honestly, I’d rather get more specific details about the star-test and what you’re seeing in it and what the reasons may be. Also, you’re seeing over-correction? That’s bizarre, particularly for a refractor that’s color corrected in the manner this is. I’d like to know more about your thoughts on the tube acclimating as well. The other thing is the Moon. For casual glances at the Moon, I get your point, but the fact that the Moon is bright does not negate the factors needed for discerning and resolving fine, intricate details. For example, the fine craterlets on the top of the lunar domes near Hortensius and Milichius. Most people glancing at the Moon would not be paying specific attention to why they would or wouldn’t be seeing these features which have to be properly highlighted after first quarter. Its like an observer who who has a 5” refractor and someone who has a 60mm refractor and everyone looking through the 60mm says... hey it looks great in this little scope too. Yea, but what are you looking at specially? What are you trying to discern or resolve? There’s a huge difference. I’ve even seen differences with eyepieces that affect the subtle features of the Moon.

Hi Daniel.  I see overcorrection because it's a simple doublet the Fresnel rings on the inside of focus, filtered or au naturel, are mushier and less distinct than the rings on the outside of focus, which is the opposite of other Synta ED doublets I've owned.

 

As for acclimation, the scope was out in stable temperatures last night (high pressure system built in) and is stored in an unheated shed.  No change in performance over the course of the 3.5 hour session.

 

I agree that there are qualitative differences to be seen scope to scope on the Moon.  However it's rare that a truly bad optic does not look, well, pretty good, on Luna if you are not being critical.  That is, the same scope that starts to put graininess in the image at 170x on Jupiter nonetheless puts up a seemingly sharp, contrasty view of the Moon at 275-300x.  Chalk it up to limitless light and lots of high contrast features (brilliant highlands and inky shadows).

 

My point about Luna is that it can mislead one into thinking the scope is better than it is.  Terestrial use is similar.  This scope was putting up wonderful views of bricks on the facade of a Target store 2 miles away.

 

Best,

 

Jim  

Edited by jrbarnett, 12 August 2018 - 07:29 PM.

[MGD]

Jim did your scope ship without a plastic protective cap over the fine focuser?  I noticed it wasn't in your original pics but others had them. Also your foam cutouts were missing in the case while others had them. Any thoughts?

Mike 

[jrbarnett]

Well if the image is breaking down at powers below 50x per inch i am sure i won't be happy with that. With my viewing tatse the scope would live at 60 to 80x per inch most of the time and be pushed to 100x per inch.  50x per inch is nothing for a super good 6" scope in my seeing.  I know for a fact i would notice ho hum optics right off the bat. So if tnis scope can't give a true sharp image at 400 to 450x i would send it back in a flash as i live at power above 60x per inch for planets and the moon..

 

Maybe a better lens in the $4k price range would be a better hit for a 6" as i would not deal with a sub par optic at the 2K price range. I am hoping the one you got was below the normal that these scopes can do and maybe they vary from OTA to OTA.  My AT102ED just keeps humming past 80x per inch and gives very sharp views.  I have kept the AT 102ED for 8 months so that should tell everyone something.

At best 600x on a 6" gets you nothing but larger scale with no additional detail.  More typically the image suffers to some degree compared to that back in the "non-empty-magnification" range.  The best magnification for high magnification observing is that magnifiication which yields more detail than any lower magnification and introduces nothing objectionable into the equation (e.g., no excessive dimming, no softness/breakdown of the image, etc.).

 

Best,

 

Jim 

[jay.i]

My point about Luna is that it can mislead one into thinking the scope is better than it is.  Terestrial use is similar.  This scope was putting up wonderful views of bricks on the facade of a Target store 2 miles away.

  Oh Jim... who doesn't love a good look at a brick wall every now and then?

[jrbarnett]

Jim did your scope ship without a plastic protective cap over the fine focuser?  I noticed it wasn't in your original pics but others had them. Also your foam cutouts were missing in the case while others had them. Any thoughts?

Mike 

No focuser cap which might have been a problem.  My scope may have been a demo/dealer sample for all I know.  And my dealer worked on it before shipping it (recentered the objective elements using instructions from Skywatcher Europe).  Anything is possible.  Mine came with a few miscellaneous imaging adapters too (Canon adapter ring, some kind of extension tube, etc.  Is that normal?

 

This is likely a very early unit.  I've heard rumors that they are going to revise the prescription/glass types to shave costs in the not too distant future, too.  It will be interesting to watch how the scope's optical group evolves.  Another interesting thing is that this scope like a few of the very earliest dealer samples (such as at NEAF) has non-typical multi-coatings.  Every Synta refractor I've ever owned (and every Long Perng who I believe to have a corporate relationship - interlocking directorates - with Synta) has used what we call "China Green" multicoatings.  These are thickly applied, deep green hued coatings.  This scope uses the more typical dual-hued formulation that you find on fancier scopes.  Perhaps the Esprits also use something other than China Green?  I've never looked down the business end of an Esprit.

 

Best,

 

Jim

[hfjacinto]

Jim,

 

This 

 

"I would put seeing last night around Pickering 7.  For planets that were better placed above the slop (Jupiter early in the session and Saturn following) the scope did a credible job.  In keeping with being a good but not great optic, usefulness in good seeing started to break down pretty early as magnification was ramped up.  At 25x per inch (150x) a very slight deterioration of image sharpness entered the equation, though more detail was seen on both gas giants despite the slight softening.  At 33x per inch (200x) things got pretty soft frankly to the point where the optic, not seeing, was doing more harm to the image than magnification was producing additional detail.  As is typical Saturn remained a little "tighter" than Jupiter at this magnification level, but at 33x per inch I was definitely trading image quality for scale.  While I'm not exactly disappointed, and my intended use of this instrument (more on this in a second) isn't affected by these results, this would not be my first choice in refractors for a planetary aficionado.  IMO the ES 127ED is the better bet, having now used four samples of that scope and been generally impressed with planetary performance up to about 40x per inch in good seeing.  But I digress."

 

Would give me pause on this scope. My 120 (on good seeing nights) has no issue with 250X. Seeing isn't always that good, but on good nights 250 is fine.

[starman876]

At best 600x on a 6" gets you nothing but larger scale with no additional detail.  More typically the image suffers to some degree compared to that back in the "non-empty-magnification" range.  The best magnification for high magnification observing is that magnifiication which yields more detail than any lower magnification and introduces nothing objectionable into the equation (e.g., no excessive dimming, no softness/breakdown of the image, etc.).

 

Best,

 

Jim 

I agree with you Jim.  Pushing a scope to higher powers that the atmosphere cannot support is useless.  They built Hubble to get around these issues.   To push the magnification to the point that the object one is viewing to the point that it is to dim to clearly see any detail is pointless.  If you want a big image to look at you get a large long focal length telescope like what pro observatories use.   

[jrbarnett]

Jim,

 

This 

 

"I would put seeing last night around Pickering 7.  For planets that were better placed above the slop (Jupiter early in the session and Saturn following) the scope did a credible job.  In keeping with being a good but not great optic, usefulness in good seeing started to break down pretty early as magnification was ramped up.  At 25x per inch (150x) a very slight deterioration of image sharpness entered the equation, though more detail was seen on both gas giants despite the slight softening.  At 33x per inch (200x) things got pretty soft frankly to the point where the optic, not seeing, was doing more harm to the image than magnification was producing additional detail.  As is typical Saturn remained a little "tighter" than Jupiter at this magnification level, but at 33x per inch I was definitely trading image quality for scale.  While I'm not exactly disappointed, and my intended use of this instrument (more on this in a second) isn't affected by these results, this would not be my first choice in refractors for a planetary aficionado.  IMO the ES 127ED is the better bet, having now used four samples of that scope and been generally impressed with planetary performance up to about 40x per inch in good seeing.  But I digress."

 

Would give me pause on this scope. My 120 (on good seeing nights) has no issue with 250X. Seeing isn't always that good, but on good nights 250 is fine.

I'm not writing it off entirely just yet.  All scopes had challenges with the poor transparency last night - we have long dense tendrils of smoke from nearby wildfires drifting through the area.  That certainly has an impact on contrast and fine detail on planetary targets.

 

It's possible that my time on Mars was especially smoky.  It's so hard to measure variable transparency due to particulates in the air, in the dark.  By day you can see the smoke tendrils.  Much harder at night.  Our site has a NELM at zenith of about 5.  It used to be darker when we started more than a dozen years ago,

 

Best,

 

Jim

[Jimmy462]

No focuser cap which might have been a problem.  My scope may have been a demo/dealer sample for all I know.  And my dealer worked on it before shipping it (recentered the objective elements using instructions from Skywatcher Europe).  Anything is possible.  Mine came with a few miscellaneous imaging adapters too (Canon adapter ring, some kind of extension tube, etc.  Is that normal?

 

This is likely a very early unit.  I've heard rumors that they are going to revise the prescription/glass types to shave costs in the not too distant future, too.  It will be interesting to watch how the scope's optical group evolves.  Another interesting thing is that this scope like a few of the very earliest dealer samples (such as at NEAF) has non-typical multi-coatings.  Every Synta refractor I've ever owned (and every Long Perng who I believe to have a corporate relationship - interlocking directorates - with Synta) has used what we call "China Green" multicoatings.  These are thickly applied, deep green hued coatings.  This scope uses the more typical dual-hued formulation that you find on fancier scopes.  Perhaps the Esprits also use something other than China Green?  I've never looked down the business end of an Esprit.

 

Best,

 

Jim

Hi Jim,

 

Thanks so much for all of your great reporting and personal attention to all of the questions and commentary that you've been fielding, it's all been very educational.

 

Having followed the various threads on these new SW scopes I must confess that it seems quite odd to me that there exists such a disparate pair of reviews as for yours and Daniel Mounsey's scopes. Is it possible that such optical manufacturing differences can arise? My initial suspicion here is that something is clearly awry.

 

That it were possible for a set of qualified eyes (knowledgeable of the SW build) to examine your scope (perhaps to the point of dismantlement and examination of the optical cell and its elements) against Daniel's (or a factory-sealed) known sample, I would be curious to find out what those inspections would reveal.

 

Color me skeptical, but something seems "not quite right" here.

 

Best,

Jimmy G

[gnowellsct]

Hi Jim,

 

 

 

Having followed the various threads on these new SW scopes I must confess that it seems quite odd to me that there exists such a disparate pair of reviews as for yours and Daniel Mounsey's scopes. Is it possible that such optical manufacturing differences can arise? My initial suspicion here is that something is clearly awry.

 

 

Best,

Jimmy G

Actually if you studying manufacturing statistical variance is very much what is going on in all products.  That's why at the high end they talk about "six sigma" as the ultimate goal in quality control.  It's also why a lot of states have "lemon laws" because some cars, really, there doesn't seem to be anything that can be done to fix them.

 

And so it is with scopes.  I suspect that your suspicion about the lens cell is likely justified.  It takes a long time to wade through this web site  but the interesting thing is that the owner intervenes in the worst cases, and does things like re-spacing lenses or re-machining a lens cell.  The fixes are not just limited to refractors.

 

Greg N

[austin.grant]

Your description of the focuser damage was tough to hear, but if the scope was a performer it was a reasonable item to repair or replace. After reading your further reviews, and the trouble you had getting decent magnification, it seems foolish to keep this sample of the scope. It is doubtful that this is a representative sample of this scope, and regardless, it sounds like a ****. Don't reward the manufacturer by keeping it... Return it as a defective, damaged on arrival piece of gear and get your money back.

[Starman81]

That’s odd Jim. How are the fires treating you now? Have you had a decent night?  I saw your comments on how it compared to the sky watcher 120 ED. I’ve used four 120ED’s and I think the 150ED was a cut above if anything. Thoughts welcome.

 

Daniel, Jim compared the 150ED to an ES 127ED and said the ES 127ED would be a better choice for a planetary enthusiast. He did not mention the SW 120ED. 

 

And the SW 120ED rates better than the ES 127ED, so I find it very hard to believe the 150ED is 'a cut above' the 120ED. In what way or ways was it a cut above? Obviously not color correction as we know the mystery glass is not the tried-and-true FPL-53 + Schott combination. Smoother optical figure? Likely tougher to do with bigger lenses and more time consuming, so more production costs and not at all likely at this price point.  

 

Your reports and Jim's report are really seemingly diametrically opposed at the moment... The only way to reconcile it could be that you got a SUPER DUPER sample and hit the optical lottery, so-to-speak, whereas Jim got a run-of-the-mill sample. Or, if yours is closer to the mean, then Jim got a lemon. 

 

I am really curious to see as time goes on how many samples are closer to Jim's and how many are closer to yours. I need to go read John Huntley's report and see where it fell. 

[MGD]

Daniel's comments to Jim concerning the SW120ED were made before Jim mentioned the ES 127 ed. In the other review John claimed the 150 was equal to his 120ed in a side by side comparison I believe. I think Jim deserves another sample to be sent to compare and keep the best. At least he could swap parts around all on their dime of course.

Mike 

[John Huntley]

Daniel's comments to Jim concerning the SW120ED were made before Jim mentioned the ES 127 ed. In the other review John claimed the 150 was equal to his 120ed in a side by side comparison I believe. I think Jim deserves another sample to be sent to compare and keep the best. At least he could swap parts around all on their dime of course.

Mike 

My 1st ED150 equalled the ED120 on colour control I felt. It's star test was not anywhere near as good as the 120 and the views of tight double stars and Saturn lacked the crispness and contrast that the ED120 was showing at similar magnifications. This ED150 unit had received a blow during transit which might have affected the collimation, notably the centering of the lens elements. The focuser optical axis alignment and the cheshire eyepiece test did not show evidence of objective tilt or focuser mis-alignment.

 

The ED150 that was sent to replace it failed the cheshire test by quite a large margin, had an awful star test and an objective lens retention ring that was not installed levelly - it was noticably tilted. I did not bother comparing this 2nd scope with any thing else. That unit is to be returned this week and I hope a 3rd one will be provided. 3rd time lucky, perhaps

 

The Skywatcher importer here in the UK has proved very responsive in replacing the scopes quickly so far, which I am grateful for.

Edited by John Huntley, 13 August 2018 - 03:49 AM.

[John Huntley]

No focuser cap which might have been a problem.  My scope may have been a demo/dealer sample for all I know.  And my dealer worked on it before shipping it (recentered the objective elements using instructions from Skywatcher Europe).  Anything is possible.  Mine came with a few miscellaneous imaging adapters too (Canon adapter ring, some kind of extension tube, etc.  Is that normal?

 

This is likely a very early unit.  I've heard rumors that they are going to revise the prescription/glass types to shave costs in the not too distant future, too.  It will be interesting to watch how the scope's optical group evolves.  Another interesting thing is that this scope like a few of the very earliest dealer samples (such as at NEAF) has non-typical multi-coatings.  Every Synta refractor I've ever owned (and every Long Perng who I believe to have a corporate relationship - interlocking directorates - with Synta) has used what we call "China Green" multicoatings.  These are thickly applied, deep green hued coatings.  This scope uses the more typical dual-hued formulation that you find on fancier scopes.  Perhaps the Esprits also use something other than China Green?  I've never looked down the business end of an Esprit.

 

Best,

 

Jim

My ED150's were both fitted with a plastic protector over the dual speed knobs of the focuser Jim. And both came with the Canon adapter and the other tube, whatever it is !. My scopes both had coatings that had more of a purple hue than the deep green that my ED120 has.

 

Thanks very much for sharing your findings with the ED150 so openly and honestly. We need this in amateur astronomy IMHO

[CHASLX200]

Okay all y'all, Jim kept a scope that I would've sent back.  So, it's probably not a good sample.  If you're debating APM vs. S-W, either buy the APM that has lots of glowing user reports, or wait until more S-W owner posts come in.

 

I sure wouldn't keep a $2500 refractor that goes soft at 30x per inch!

I agree. Even if it goes soft 60x per inch it would go back jack.

[CHASLX200]

Hi Daniel.  I see overcorrection because it's a simple doublet the Fresnel rings on the inside of focus, filtered or au naturel, are mushier and less distinct than the rings on the outside of focus, which is the opposite of other Synta ED doublets I've owned.

 

As for acclimation, the scope was out in stable temperatures last night (high pressure system built in) and is stored in an unheated shed.  No change in performance over the course of the 3.5 hour session.

 

I agree that there are qualitative differences to be seen scope to scope on the Moon.  However it's rare that a truly bad optic does not look, well, pretty good, on Luna if you are not being critical.  That is, the same scope that starts to put graininess in the image at 170x on Jupiter nonetheless puts up a seemingly sharp, contrasty view of the Moon at 275-300x.  Chalk it up to limitless light and lots of high contrast features (brilliant highlands and inky shadows).

 

My point about Luna is that it can mislead one into thinking the scope is better than it is.  Terestrial use is similar.  This scope was putting up wonderful views of bricks on the facade of a Target store 2 miles away.

 

Best,

 

Jim  

I agree about lunar details vs the planets. I had a real bad 18" Tectron Dob 3 years ago with a Nova mirror. Low power deep sky was fine and the moon looked pretty good at 200x, but Jupiter was always one turn of the focus knob away from snapping in sharp.  The planet would never get sharp. Had to be the worst mirror i ever owned.  So even the so called high end optics and have duds.

[CHASLX200]

At best 600x on a 6" gets you nothing but larger scale with no additional detail.  More typically the image suffers to some degree compared to that back in the "non-empty-magnification" range.  The best magnification for high magnification observing is that magnifiication which yields more detail than any lower magnification and introduces nothing objectionable into the equation (e.g., no excessive dimming, no softness/breakdown of the image, etc.).

 

Best,

 

Jim 

600x is only good for star images and the moon as my 125 ETX still did pretty good at 600x on the moon.  Forget planets at 100x per inch on any scope as they get too dim Jim.