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SW 180mm Mak just ordered

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#1 precaud

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Posted 21 November 2018 - 12:41 PM

I just ordered a new SW 180 Mak from our host. Was considering the Orion version but with the sale price the difference wasn't worth considering, and I do like to support this site's sponsor.

 

This replaces a 6" F/8 achro that was not being used much since getting the ES ED127. It will live on an ASGT. I would have preferred more aperture, but I think this is the largest Mak that would work well on that mount, and a good tradeoff between size and portability. It is my first scope of this type, all prior ones being newts and fracs. So I look forward to playing with it.

 


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#2 junomike

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Posted 21 November 2018 - 01:39 PM

Great choice.

I really liked the 7" Mak , especially  for Lunar views.


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#3 Peter Besenbruch

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Posted 21 November 2018 - 05:46 PM

I just ordered a new SW 180 Mak from our host. Was considering the Orion version but with the sale price the difference wasn't worth considering, and I do like to support this site's sponsor.

 

This replaces a 6" F/8 achro that was not being used much since getting the ES ED127. It will live on an ASGT. I would have preferred more aperture, but I think this is the largest Mak that would work well on that mount, and a good tradeoff between size and portability. It is my first scope of this type, all prior ones being newts and fracs. So I look forward to playing with it.

Very nice, and welcome to the club. We are an elite group of people who only settle for the best, and never want to pay for it. ;) Enjoy.


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#4 precaud

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Posted 21 November 2018 - 07:17 PM

Very nice, and welcome to the club. We are an elite group of people who only settle for the best, and never want to pay for it. wink.gif Enjoy.

The word you're looking for is "discerning"... 

 

It also means I have one more forum to frequent here   :)


Edited by precaud, 21 November 2018 - 07:20 PM.

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#5 dscarpa

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Posted 22 November 2018 - 07:23 PM

 Speaking as the owner of a IM715 I think you'll like it. Excellent for lunar-planetary and doubles of course but quite good for DSOs as well. David


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#6 Tyson M

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Posted 22 November 2018 - 11:24 PM

I was very close to buying one again. I tried it and liked it a lot, but not as an only scope.  I wanted to starhop and learn a bit more.

 

Optically they are very good.  They almost needs tracking, unless you are a great starhopper.  Now that I don't need one scope as an only scope, I would buy one again, that is the SW version for the larger 2" SCT threaded opening. 



#7 Peter Besenbruch

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Posted 23 November 2018 - 12:37 PM

I was very close to buying one again. I tried it and liked it a lot, but not as an only scope.  I wanted to starhop and learn a bit more.

 

Optically they are very good.  They almost needs tracking, unless you are a great starhopper.  Now that I don't need one scope as an only scope, I would buy one again, that is the SW version for the larger 2" SCT threaded opening. 

These scopes have just under a degree field of view. If you are going to star hop any distance, it's better to mount an 80mm finder on it. Perhaps one with an air spaced, f5-ish objective that supports 2" eyepieces. Also, it's easier to hop with an equatorial mount than an alt-az, particularly when using printed star maps.

 

For high power work, tracking is very nice. Again, equatorials tend to dominate here, though a few high end alt-az mounts offer tracking as an option. The Celestron offerings tend to be too unstable and/or too short.


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#8 dscarpa

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Posted 23 November 2018 - 02:41 PM

 I have zero problem tracking manually with my IM715D with 2" back on a Giro 3 mount and high power is used a lot. On a mount with bad action it's a pain with any scope. I use a combo of 50mm SV finder and red dot which is good for most objects in my darkish back yard but the 80mm on my C9.25 is a lot better. It's much easier to star hop on a GEM. In the olden days I used a 1* FOV eyepiece and  scale with 1* increments scaled to my star atlas. I then paced  it off on both axis from a known star or DSO with my 6" newt on a GEM.  David


Edited by dscarpa, 23 November 2018 - 02:42 PM.

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#9 precaud

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Posted 25 November 2018 - 03:34 PM

It arrived yesterday afternoon in good shape (FedEx Home delivers on Saturdays). Chunky little dude. It mounts up nicely on the AS-GT. With a Baader 1.25" prism diagonal and my heaviest 1.25" eyepiece installed, the one 11-lb. counterweight balances it just fine. The finder will require a little more. If I go to the supplied 2" diagonal and some bigger glass, it'll have to add another pound or two. For first light, I'll stick with the 1.25".

 

The ergonomics look promising for using just a standard telescoping office chair for observing. I like that.

 

I have a roll of Reflectix but will try it first without it. First light may actually be tonight, as we're in a "calm after the storm" phase here, though its pretty cold out (41ºF high this afternoon, 19ºF low tonight). I'll put the scope out a couple hours early to acclimate.

 

Knowing that I'll need a storage bag/case for it, I looked around today and found this 30x14x14" padded gear bag for $52, and ordered one:

https://www.bhphotov...ng_Fixture.html

Sizing looks just about right.


Edited by precaud, 25 November 2018 - 03:35 PM.

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#10 precaud

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Posted 26 November 2018 - 09:22 AM

Last night, first light in the SW180 was hindered by thin high clouds gradually moving in from the NW about a 1/2 hour after I started. The OTA was set out at 41ºF 2-1/2 hours in advance to acclimate. It was 34º when I started. With that amount of "cooling" time, tube thermals were pretty well behaved but a star test showed the optics were severely over- or under-corrected (I forgot to ascertain which it was). So views were not very impressive. Since temps were still falling, I could only hope that the figure would improve later. In the meantime, I concentrated on getting to know the ergonomics, etc.

 

My fantasy of using an office chair for observing held good, except for objects within say 20º of zenith, which will require something lower. The ergonomics are much improved over the 6" F/8 frac it replaced.

The straight-through finder is good but I may replace it with a RACI/RDF combo next time out. Or maybe not - this will pretty much live on the goto mount, making the finder less relevant. Maybe an RDF only would do? What are other owners of this scope using?

Speaking of mount, the ASGT proved to be a very good match for the SW180.

This was my first time using a Mak, and hence first experience of "image shift" while focusing. It was quite pronounced. How much is considered normal for one of these?

 

My longest FL 1.25" eyepiece is a 35mm Orion Ultrascopic, which worked well with the scope and resulted in 77X magnification. I will probably be using that eyepiece a lot with this scope. The FOV is surprisingly small with it, and probably won't improve much if at all with my 2" 40mm Sterling plossl.

 

A little before 9pm the haloed moon was peeking up above the mountains to the east, revealing just how bad the transparency had become. I decided to call it a night, but first did a star test using Aldebaran, and took a quick look at nearby Uranus. The star test was much improved over the earlier one, patterns appearing essentially the same on both sides of focus. Phew. That was good to see. Collimation may be just a tad off, I'll check that out in more accommodating conditions. Set the goto for Uranus, put a 12.5mm in the focuser, and was greeted with a clearly-defined light blue orb at 216X. Stars in the fov were pinpoint.

 

All in: a) It's an enjoyable, easy-to-use scope, a high magnification specialist. b) I'm pretty sure I didn't get a lemon, and c) The image shift thing is really annoying and needs to be addressed.


Edited by precaud, 26 November 2018 - 09:26 AM.

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#11 rmollise

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Posted 26 November 2018 - 09:56 AM

Last night, first light in the SW180 was hindered by thin high clouds gradually moving in from the NW about a 1/2 hour after I started. The OTA was set out at 41ºF 2-1/2 hours in advance to acclimate. It was 34º when I started. With that amount of "cooling" time, tube thermals were pretty well behaved but a star test showed the optics were severely over- or under-corrected (I forgot to ascertain which it was). So views were not very impressive. Since temps were still falling, I could only hope that the figure would improve later. In the meantime, I concentrated on getting to know the ergonomics, etc.

 

My fantasy of using an office chair for observing held good, except for objects within say 20º of zenith, which will require something lower. The ergonomics are much improved over the 6" F/8 frac it replaced.

The straight-through finder is good but I may replace it with a RACI/RDF combo next time out. Or maybe not - this will pretty much live on the goto mount, making the finder less relevant. Maybe an RDF only would do? What are other owners of this scope using?

Speaking of mount, the ASGT proved to be a very good match for the SW180.

This was my first time using a Mak, and hence first experience of "image shift" while focusing. It was quite pronounced. How much is considered normal for one of these?

 

My longest FL 1.25" eyepiece is a 35mm Orion Ultrascopic, which worked well with the scope and resulted in 77X magnification. I will probably be using that eyepiece a lot with this scope. The FOV is surprisingly small with it, and probably won't improve much if at all with my 2" 40mm Sterling plossl.

 

A little before 9pm the haloed moon was peeking up above the mountains to the east, revealing just how bad the transparency had become. I decided to call it a night, but first did a star test using Aldebaran, and took a quick look at nearby Uranus. The star test was much improved over the earlier one, patterns appearing essentially the same on both sides of focus. Phew. That was good to see. Collimation may be just a tad off, I'll check that out in more accommodating conditions. Set the goto for Uranus, put a 12.5mm in the focuser, and was greeted with a clearly-defined light blue orb at 216X. Stars in the fov were pinpoint.

 

All in: a) It's an enjoyable, easy-to-use scope, a high magnification specialist. b) I'm pretty sure I didn't get a lemon, and c) The image shift thing is really annoying and needs to be addressed.

Any moving mirror focusing scope in this price range will show some image shift. Around 45" of shift is pretty much normal.

 

If you want a little more field (understanding that a high focal ratio MCT is not a wide-field instrument), look for an eyepiece with a larger AFOV instead of more focal length. Using a 40mm Plossl is like looking through a keyhole. ;)



#12 precaud

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Posted 26 November 2018 - 10:43 AM

Any moving mirror focusing scope in this price range will show some image shift. Around 45" of shift is pretty much normal.

 

OK, thanks for the context.

 

If you want a little more field (understanding that a high focal ratio MCT is not a wide-field instrument), look for an eyepiece with a larger AFOV instead of more focal length. Using a 40mm Plossl is like looking through a keyhole. [;)]

 

A 40mm 1.25" plossl has drinking-straw FOV, yes, But the 2" Sterling 40mm has the same 55-56º as the rest of the line, and the big eye lens makes it feel bigger than that.



#13 rmollise

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Posted 26 November 2018 - 12:48 PM

OK, thanks for the context.

 

 

A 40mm 1.25" plossl has drinking-straw FOV, yes, But the 2" Sterling 40mm has the same 55-56º as the rest of the line, and the big eye lens makes it feel bigger than that.

 

If you're happy with it, that's great. But it's easy enough to get to 70 plus degrees of AFOV these days without spending a whole lot of money. To _me_ 56-degrees is still "keyhole peeping." ;)



#14 precaud

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Posted 26 November 2018 - 04:35 PM

If you're happy with it, that's great. But it's easy enough to get to 70 plus degrees of AFOV these days without spending a whole lot of money. To _me_ 56-degrees is still "keyhole peeping." wink.gif

 

Well, to each their own, for sure.

 

I have wider-AFOV EP's, I just haven't gotten to using 2-inchers with it yet. And its not as though the choice is wide open and only determined by user preference. I have read that the 180 Maks have a rear cell opening of 31mm. Which, IIUC, means that any eyepiece with field stop larger than that will vignette. How visible that will be remains to be seen.



#15 luxo II

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Posted 26 November 2018 - 04:40 PM

Well you should try it, the vignetting isn’t a hard cut-off as you appear to assume. TMB Paragons and a 38mm 70 degree SWA are just fine in your scope. Best low power eyepiece of all however IMHO was a 50mm Vixen LV which gave a view of clusters like diamonds on black velvet.
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#16 Peter Besenbruch

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Posted 26 November 2018 - 09:17 PM

A little before 9pm the haloed moon was peeking up above the mountains to the east, revealing just how bad the transparency had become. I decided to call it a night, but first did a star test using Aldebaran, and took a quick look at nearby Uranus. The star test was much improved over the earlier one, patterns appearing essentially the same on both sides of focus. Phew. That was good to see. Collimation may be just a tad off, I'll check that out in more accommodating conditions. Set the goto for Uranus, put a 12.5mm in the focuser, and was greeted with a clearly-defined light blue orb at 216X. Stars in the fov were pinpoint.

 

All in: a) It's an enjoyable, easy-to-use scope, a high magnification specialist. b) I'm pretty sure I didn't get a lemon, and c) The image shift thing is really annoying and needs to be addressed.

Not a bad first light. Next comes collimation with a 15mm and a 7mm eyepiece. Be sure to check your diagonal against the straight through collimation. Then, possible insulation and a 40mm, 2" eyepiece. Yes, you will notice dimming, but you will get the whole field. Eventually, you might want to get a 55-60mm eyepiece if you want to use an OIII filter.


Edited by Peter Besenbruch, 26 November 2018 - 11:41 PM.

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#17 Tyson M

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Posted 26 November 2018 - 09:36 PM

The optics on these are almost unanimously good from anyone who buys it.

 

The image shift is the price to pay, mine had it. In bad seeing it was awful to use and try to focus, but that is like that with any scope.

 

Getting a new focuser on it can help mitigate that. I think a budget 40mm widefield is a great idea as well. 


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#18 Rock22

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Posted 26 November 2018 - 09:36 PM

I so enjoy using my 180mm mak.  I consider it the best scope purchase I've made so far, and I use it for visual and basic astrophotography. Just like the OP said, a good all-around scope.  (Second best purchase was the ES FirstLight 4" f/9.8 achro refractor for $140.)

 

I am not bothered at all by the narrow FOV, and have never found it a problem.  Insulation works for me, so I hope you are able to wrap it up and use it often.  Congratulations on the new scope!


Edited by Rock22, 26 November 2018 - 09:39 PM.

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#19 precaud

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Posted 09 December 2018 - 12:45 AM

I spent some time this evening going through the scope and all of the accessories, checking for proper collimation and alignment.

 

Everything is spot on. Including the supplied 2" diagonal.

 

This is the first scope I've ever got that is requiring no adjusting or tweaking.

 

Kudos to Skywatcher for the excellent QC. You guys have upped your game considerably.


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#20 RAKing

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Posted 10 December 2018 - 02:58 PM

Well you should try it, the vignetting isn’t a hard cut-off as you appear to assume. TMB Paragons and a 38mm 70 degree SWA are just fine in your scope. Best low power eyepiece of all however IMHO was a 50mm Vixen LV which gave a view of clusters like diamonds on black velvet.

I agree!  I haven't figured out the "magic number" for vignetting, but I use a Pentax XW 40 with a 2-inch diagonal on my MCT with no problems.  And yes, the view is like diamonds on black velvet.  cool.gif 

 

Cheers,

 

Ron



#21 Peter Besenbruch

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Posted 10 December 2018 - 09:50 PM

I agree!  I haven't figured out the "magic number" for vignetting, but I use a Pentax XW 40 with a 2-inch diagonal on my MCT with no problems.  And yes, the view is like diamonds on black velvet.  cool.gif

I can see vignetting with a 40mm wide angle, but I still use it on my 180. I also use a 56mm Plössl in conjunction with my OIII filter.



#22 precaud

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Posted 10 December 2018 - 11:47 PM

I think I'll try my 40mm 2" Sterling plossl first, before getting a 40WA for it. I have a 34mm Meade SWA but that thing is really heavy. I need to add some counterweight before putting a 2" diagonal and accessories on. The 1.25" prism diagonals are flyweights by comparison.

 

I got different results star testing the scope last night than on night one. It could be that it never achieved thermal stability, temps were dropping 4-5ºF per hour. I then read numerous posts about start-testing Maks and am now uncertain about what it is I should be looking for. Perhaps the best thing is to use this as an incentive to get my DPAC rig up and working again. Gotta make a new eyepiece for it. Much easier to interpret the results, and no thermals involved.



#23 precaud

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Posted 12 December 2018 - 10:06 PM

The star test results last night freaked me out. Even after three hours, the obstruction "hole" was dark on one side of focus but had rings on the other. Sign of significant SA. Haven't had the scope long enuf to know if this was just from it still being unacclimated, or maybe this is just the way it is.

 

So I set it up for terrestrial viewing today, using glints off of powerline ceramic insulators down the street. Some of them also have small print on them that aids in judging detail, The scope storage room was the same temp as outside so no acclimation was needed, but I gave it 1/2 hour anyway.

 

I was relieved to see that the star test rings were once again pretty much the same on both sides of focus, just as I had seen the first night.

 

So I explored magnification, taking it in steps up to 300X. Quite amazing to see it maintaining sharpness when the air was still.

 

I also compared the stock 2" mirror diagonal to a 2" TeleVue Everbright Dielectric. The TV may have been a skosh brighter. But I saw no difference in detail between them, even at 300X. Not even a hint of astig, which is so common in flats.

 

Very impressive.


Edited by precaud, 12 December 2018 - 10:08 PM.


#24 Peter Besenbruch

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Posted 14 December 2018 - 01:55 PM

So I explored magnification, taking it in steps up to 300X. Quite amazing to see it maintaining sharpness when the air was still.

300x? The scope is just getting started! ;) I've used 540x on the moon, and 450x on Saturn. Enjoy.


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#25 precaud

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Posted 14 December 2018 - 02:49 PM

300x? The scope is just getting started! wink.gif I've used 540x on the moon, and 450x on Saturn. Enjoy.

 

Well it remains to be seen if the optics in this one are that good... from what I've seen thus far, I won't be able to explore that territory until winter passes.

 

And it must be said... how often does seeing here allow for such high powers? Rarely...


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