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Where are the Mak-Newt people?

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#76 glend

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Posted 20 September 2015 - 05:42 PM

Pushing long focal length scopes visually is one way of getting high magnification if your chasing that.  My iStar 127mm f12 R30 antiastigmatic refractor (which I built) is a good planet scope (with it's 1275mm focal length) and the colour rendition is not bad considering its an Achro with 30% reduction type glass. At f12 there is little CA to worry about anyway (easily cleaned out with the Baader Semi-APO filter) but I would not want to image through it and it's hard to guide a long refractor anyway.


Edited by glend, 20 September 2015 - 05:44 PM.


#77 Star Ship

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Posted 15 October 2015 - 06:51 PM

I keep reading the post of you Mak-Newt people about the "best-kept secret in astronomy" the Mak-Newt.  Thus, today I took the plunge and picked up a used Orion 190. Looks to be in great shape-- no squirrel nest in between the glass-- I'll let you know how it works out, with numerous, boring post, about overdone topics.  Really, thanks to you all for the excellent info. :)


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#78 bierbelly

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Posted 22 October 2015 - 10:53 AM

:gotpopcorn:



#79 Drew57

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Posted 22 October 2015 - 02:38 PM

frosty.jpg

 

You read my mind bierbelly, a 2" OIII filter is next on my list! Well, that and a ES 82o series 30mm eyepiece and rotating ring$...and..?

 

I was in Wisconsin under some very cold but good viewing, and on each of the nebula viewed clean also swapped in a Tele Vue NebuStar filter; which was certainly some improvement in finer or extended detail. It still amazes me how well a little 6" scope does in some good seeing. Going to have to go to a club event since the views through those big cats & dobs I'm reading about on CN will blow me away.

 

Thank goodness for the Kendrick system, or the viewing would have been over very soon.

 


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#80 BLACKDRAGON

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Posted 22 October 2015 - 03:44 PM

attachicon.giffrosty.jpg

 

You read my mind bierbelly, a 2" OIII filter is next on my list! Well, that and a ES 82o series 30mm eyepiece and rotating ring$...and..?

 

I was in Wisconsin under some very cold but good viewing, and on each of the nebula viewed clean also swapped in a Tele Vue NebuStar filter; which was certainly some improvement in finer or extended detail. It still amazes me how well a little 6" scope does in some good seeing. Going to have to go to a club event since the views through those big cats & dobs I'm reading about on CN will blow me away.

 

Thank goodness for the Kendrick system, or the viewing would have been over very soon.

 

That looks cold enough to have to look for two spherical objects that might have dropped off your equipment!!!    



#81 Drew57

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Posted 22 October 2015 - 09:07 PM

frosty2.jpg

 

I was tenting it, and climbing into the frozen sleeping bag at 2 or 3 am definitely took sleep from the eyes for a bit! But I had a good down bag and 3 1/2" thick sleeping pad for my old bones. When frost forms does the air get drier and clearer? The sky grew more crystal clear as the night went on at least to my light polluted city eyes...or maybe the wine was wearing off!

 

The polar scope eyepiece in the mount dewed up immediately but I got dead-on R.A. alignment anyway. The finder scope suffered the same; so I used a Hotech laser for rough aim sometimes. I try to avoid using the laser as it can disturb others who want a natural experience, but its only on for 30 seconds or so each time. I'm still having issues during star alignment with the iOptron mount, but everything worked great optically at least. I'm missing something with the alignment procedure, but will figure it out.

 

In any case the f/4.8 Mak-Newt can be slewed to a location and objects picked up pretty quick given the wide field; or even unclutched and visually pointed, locked, and set to track. I had about 2.7o true field with the 20mm EP. Stars nice and sharp to very near the extreme edges in the EP, so anyone would be very satisfied with the quality of this type of scope.

 

Also, very glad I found CN as there is a wealth of information and cool people to converse with from all over the world. CN will definitely enhance my experiences ongoing now that I'm finally using some equipment instead of just having read/learned about astronomy.

 

So one Mak-Newt person is newly kicking around MN & WI. I've got my mind set on going down to Texas near Big Bend NP, as I once paddled, climbed, and hiked there. On top of the Mesa De Anguila I saw stars and milky way unmatched in all my experience, surpassing even the deep BWCA and Quetico canoe wilderness.

frosty3.jpg


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#82 Eric Seavey

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Posted 28 February 2016 - 06:13 PM

I got one a month ago!  Definitely a deep space astrograph, and not great for planetary imaging like the 11 to 14 inch scopes.... The images taken with a MN 190 appear calmer or something... don't know how to explain it.  All the stars are little round discs from edge to edge.  Here is my setup with an autoguider on the Orion Atlas Pro AZ/EQ-G that has two nice features I like:  One is the extra saddle for a secondary scope.. in my case the autoguider. Second, is the DSLR camera control.  Of course I could purchase these separately and buy a less expensive mount, but would end up paying about the same as this package.  I will capture Pleiades again and framed better than my previous try, and will post it here.

IMG_0723.JPG

Edited by Eric Seavey, 29 February 2016 - 12:15 PM.

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#83 bierbelly

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Posted 01 March 2016 - 11:59 AM

I got one a month ago!  Definitely a deep space astrograph, and not great for planetary imaging like the 11 to 14 inch scopes.... The images taken with a MN 190 appear calmer or something... don't know how to explain it.  All the stars are little round discs from edge to edge.  Here is my setup with an autoguider on the Orion Atlas Pro AZ/EQ-G that has two nice features I like:  One is the extra saddle for a secondary scope.. in my case the autoguider. Second, is the DSLR camera control.  Of course I could purchase these separately and buy a less expensive mount, but would end up paying about the same as this package.  I will capture Pleiades again and framed better than my previous try, and will post it here.

Nice setup.  One thought though.  That little Celestron power pack may not have enough juice to power all of your mount and the accessories all night, and it takes a while to recharge it.  Especially true if you find it necessary to use a dew heater.



#84 Patrick

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Posted 01 March 2016 - 04:51 PM

 

 

I have a wonderful Skywatcher MN190 Mak-Newt, but they seem to be orphans on Cloudy Nights. Where do they hang out?

Not many Mak-Newts are sold globally I suspect.  I've had a couple.  I prefer a straight Newt to a Mak-Newt to be honest.  It's just simpler, lighter and cheaper, with few drawbacks other than diffraction spikes from the spider arms.  I don't dislike them by any means.  I just don't find that they add enough extra compared to the more common similar alternative.

 

- Jim 

 

 

Good points Jim but the M-W Mak-Newts mitigate pretty much everything you mention except the cheaper part.    Also remember they have substantially less coma than an equivalent F ratio Newt (and adding a Paracor starts to complicate the Newt).  The meniscus is no more complicated nor more prone to dewing than the front element of a refractor and refractors are noted for their fuss-free-ness.

 

It does come at a hefty price though relative to a conventional Newt and the Mak-Newt is no exception to the good old Law of Diminishing Returns, but it's not flagrant about it either, especially compare to an equal aperture APO. 

 

Jeff

 

 

I think I have to agree with Jim here.  A simpler Newtonian in the f/6 to f/8 range (ie 8" f/6 or 6" f/8) can put up some very stunning views.  I'm not sure what you mean by a Paracorr complicating the Newt, since that's what they were designed for, but then even without it,  at f/6 to f/8 a Newt does not have annoyingly bad coma. 

 

I owned and used a ES 6" Comet Hunter for a few seasons but finally sold it because the views through it were no better than my C6 (at higher powers) and not nearly as good as my Edge 8.  The main advantage of the Comet Hunter was it's flat and wide field of view.  But for it's aperture, it's very heavy and cumbersome.

 

I suspect it's for those reasons that they're not more popular.

 

Patrick



#85 bierbelly

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Posted 02 March 2016 - 01:57 PM

Sometimes the wide, flat field of a MakNewt can be a positive boon.  On a particularly dark night (Cherry Springs State Park, IIRC) I was able to see what appeared to be the entire Pleiades cluster (or most of it anyway), including some nebulosity.  Both portions of the Double Cluster in one eyepiece field.  A significant extent of the Veil nebula, without a filter.  More recently I was able to see the Andromeda galaxy including a lot more than just the center bulge. Wide field has it's advantages, especially at a dark sky site.  Some things just don't look as good up close.



#86 rjbokleman

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Posted 04 April 2016 - 04:42 PM

What a great thread.  I'm thinking of picking up the SW or Orion.  Why would one pay an extra $100.00 for the Orion other than the color difference between Black and White?  Anyone know?

 

Orion

http://www.telescope...Tax_Blues-09978

 

SW

http://skywatcherusa...nian-190mm.html

 

I'm looking to gather more light and more detail in my AP efforts.  I was thinking about an AT8RC (Carbon) to get more focal length over my SW100ED Refractor or perhaps even an Edge 8 HD.  All different beasts for sure.  The RC would give me some nice diffraction spikes that the others would not and I like those from my attempts with a standard Newt, but hate the vignetting you get from any kind of standard Newt.  Even the new SW Quattro's have a big vignetting issue with the secondary.

 

My understanding of the Mak-Newt is that it will provide similar or better performance to my SW100ED, but faster and more resolution given it's 190mm diameter.  I might miss the diffraction spikes of the RC/Newt, but I think I can live without those.  If I'm ambitious they could be added during post processing.  :lol:

 

BTW, this would go on my iOptron iEQ45 Pro.  I'm assuming that's enough mount for this scope?


Edited by rjbokleman, 04 April 2016 - 04:44 PM.


#87 Mike Conley

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Posted 27 April 2016 - 07:33 AM

 

 

 

I have a wonderful Skywatcher MN190 Mak-Newt, but they seem to be orphans on Cloudy Nights. Where do they hang out?

Not many Mak-Newts are sold globally I suspect.  I've had a couple.  I prefer a straight Newt to a Mak-Newt to be honest.  It's just simpler, lighter and cheaper, with few drawbacks other than diffraction spikes from the spider arms.  I don't dislike them by any means.  I just don't find that they add enough extra compared to the more common similar alternative.

 

- Jim 

 

 

Good points Jim but the M-W Mak-Newts mitigate pretty much everything you mention except the cheaper part.    Also remember they have substantially less coma than an equivalent F ratio Newt (and adding a Paracor starts to complicate the Newt).  The meniscus is no more complicated nor more prone to dewing than the front element of a refractor and refractors are noted for their fuss-free-ness.

 

It does come at a hefty price though relative to a conventional Newt and the Mak-Newt is no exception to the good old Law of Diminishing Returns, but it's not flagrant about it either, especially compare to an equal aperture APO. 

 

Jeff

 

 

I think I have to agree with Jim here.  A simpler Newtonian in the f/6 to f/8 range (ie 8" f/6 or 6" f/8) can put up some very stunning views.  I'm not sure what you mean by a Paracorr complicating the Newt, since that's what they were designed for, but then even without it,  at f/6 to f/8 a Newt does not have annoyingly bad coma. 

 

I owned and used a ES 6" Comet Hunter for a few seasons but finally sold it because the views through it were no better than my C6 (at higher powers) and not nearly as good as my Edge 8.  The main advantage of the Comet Hunter was it's flat and wide field of view.  But for it's aperture, it's very heavy and cumbersome.

 

I suspect it's for those reasons that they're not more popular.

 

Patrick

 

So in your opinion Patrick the claims of apo refractor performance are false? I've never looked through a MN design but have been very impressed with newtonian scopes.

Mike



#88 GJJim

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Posted 30 April 2016 - 10:03 AM

 

I think I have to agree with Jim here.  A simpler Newtonian in the f/6 to f/8 range (ie 8" f/6 or 6" f/8) can put up some very stunning views.  I'm not sure what you mean by a Paracorr complicating the Newt, since that's what they were designed for, but then even without it,  at f/6 to f/8 a Newt does not have annoyingly bad coma. 

 

I owned and used a ES 6" Comet Hunter for a few seasons but finally sold it because the views through it were no better than my C6 (at higher powers) and not nearly as good as my Edge 8.  The main advantage of the Comet Hunter was it's flat and wide field of view.  But for it's aperture, it's very heavy and cumbersome.

 

I suspect it's for those reasons that they're not more popular.

 

Patrick

 

So in your opinion Patrick the claims of apo refractor performance are false? I've never looked through a MN design but have been very impressed with newtonian scopes.

Mike

 

My Intes-Micro MN74 is a Mak-Newt designed for use as an astrograph. It has a large CO and to even view with eyepieces, it requires an extension tube in the focuser. But oddly enough at outreach events it puts up fantastic views of Jupiter -- views that are sharp, contrasty, full of detail -- very refractor like. Unlike a refractor, a short focal ratio MNT requires regular fiddly collimation. 



#89 glend

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Posted 30 April 2016 - 06:42 PM

What a great thread.  I'm thinking of picking up the SW or Orion.  Why would one pay an extra $100.00 for the Orion other than the color difference between Black and White?  Anyone know?

 

Orion

http://www.telescope...Tax_Blues-09978

 

SW

http://skywatcherusa...nian-190mm.html

 

I'm looking to gather more light and more detail in my AP efforts.  I was thinking about an AT8RC (Carbon) to get more focal length over my SW100ED Refractor or perhaps even an Edge 8 HD.  All different beasts for sure.  The RC would give me some nice diffraction spikes that the others would not and I like those from my attempts with a standard Newt, but hate the vignetting you get from any kind of standard Newt.  Even the new SW Quattro's have a big vignetting issue with the secondary.

 

My understanding of the Mak-Newt is that it will provide similar or better performance to my SW100ED, but faster and more resolution given it's 190mm diameter.  I might miss the diffraction spikes of the RC/Newt, but I think I can live without those.  If I'm ambitious they could be added during post processing.  :lol:

 

BTW, this would go on my iOptron iEQ45 Pro.  I'm assuming that's enough mount for this scope?

I have both the Skywatcher MN190 and the RC08, and I can say that I enjoy imaging through the MN190 much more. Sure the RC08 has a longer focal length and can ''get in close'' but its long focal length means it is slow in comparison. The small central obstruction of the MN190 is a clear winner on contrast.  For narrow band imaging I am using the MN190 pretty much exclusively, for OSC imaging I use the RC08. Sure the RC is lighter, but the MN190 does not tax my NEQ6 on the pier.  Forget SW100EDs I used to have one and go rid of it, as with the RC is was slow. 

If you have to have one scope get the MN190. And for the guy that was debating the Skywatcher or Orion version, I can't see what Orion is offering to justify a $100 price premium other than jacking up their profit margin. Orion actually got out of the MN market for a few years and Skywatcher stuck with it and built up a following.  The Orion initially offered a larger secondary (bigger central obstruction and lower contrast), but the Skywatcher was optimised on the smaller secondary which is large enough for any APS-C sized sensor.  I am not a fan of the Skywatcher or Orion focuser and the slide out extension tube, frankly it is sloppy when your imaging with a DSLR.  Moonlight finally have a focuser adaptor that suits the MN190. Initial attempts by people to upgrade the focuser failed to take into account the need to move the focuser up and down the tube to properly centre it over the secondary (which of course is mounted further forward on the corrrector lense). After sending drawings and photos to Ron at Moonlight he has changed the MN190 adaptor to provide the same range of up and down adjustment that the stock focuser provides, and he has them in production now (so he tells me).



#90 David_Ritter

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Posted 30 April 2016 - 07:23 PM

Finally got around to posting a picture of my MN190:

 

EQ8 with the MN190 and GSO 6" Newt

 

In this photo its set up for imaging from my back yard in the city. Piggybacked on top is a GSO 6" f6 Newtonian which is being used as the guide scope.

 

I also have a home-made dob mount for the MN190 that I usually use in the winter. Works very well as a grab-and-go scope on the dob. (ok, lug-and-go might be a better description)


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#91 dr.who

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Posted 01 May 2016 - 05:15 PM

Well... I am (again) a MN person. I bought the ES Comet Hunter yesterday. I realized that my least expensive outreach scope was several thousand dollars and wasn't keen on that. Especially after last night with several kids running and playing tag around the AP 155. So hello new outreach scope! It is physically bigger than the ES 102 (people at an outreach tend to go to the biggest scope on the field first even if the views are better in a smaller scope) and puts up views equal to the ES 127 so it should be perfect. Plus no squatting on the ground or climbing ladders for people trying to view.

I would have loved to get the SW 190 but it was out of budget. Maybe later I will upgrade...
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#92 PowellAstro

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Posted 01 May 2016 - 08:47 PM

@ Dr. Who

Can you post some close up pics of the CH and would love to hear more on optical performance.

#93 dr.who

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Posted 02 May 2016 - 11:22 AM

When it arrives I will be happy to. Anything in particular you are looking to see? As to performance, I had one before. It performed very well with crisp clean pinpoint stars to the edge of the field. It was very close in performance to my 127 APO which is why it was sold. Too close in performance. I am buying it again because it will be for outreach use and some EAA. I plan to test it with my QSI and Astro Toaster to see if the 814 chip will do as well as the APS-C for near real time observing (NRTO) of DSO.



#94 Yu Gu

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Posted 02 May 2016 - 11:30 AM

Hi David,

 

I see you upgraded the focuser to a feathertouch. Which adapter did you use?

 

Thanks!

Gu

 

Finally got around to posting a picture of my MN190:

 

 

 

In this photo its set up for imaging from my back yard in the city. Piggybacked on top is a GSO 6" f6 Newtonian which is being used as the guide scope.

 

I also have a home-made dob mount for the MN190 that I usually use in the winter. Works very well as a grab-and-go scope on the dob. (ok, lug-and-go might be a better description)



#95 PowellAstro

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Posted 02 May 2016 - 11:56 AM

When it arrives I will be happy to. Anything in particular you are looking to see? As to performance, I had one before. It performed very well with crisp clean pinpoint stars to the edge of the field. It was very close in performance to my 127 APO which is why it was sold. Too close in performance. I am buying it again because it will be for outreach use and some EAA. I plan to test it with my QSI and Astro Toaster to see if the 814 chip will do as well as the APS-C for near real time observing (NRTO) of DSO.


This sounds really good. Was it sharp to the edge with the ES 82 degree 30mm? How was the high power for planetary viewing? It would be good to see close ups of the primary mirror cell adjustments and the secondary housing. Did you do any star test?

#96 tazer

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Posted 02 May 2016 - 05:18 PM

Until dr.who's ESLCH arrives I'll do my best to answer questions.

 

The ESLCH is a bit finicky to collimate but if you bear with it the rewards are great. The CO% is larger than most MNs but then this scope is geared more toward imaging. Nonetheless it provides some spectacular views.

 

I've had some great views of Jupiter at 311X (ES 82 4.7mm with TeleVue 2X Barlow.) I haven't used the ES 82 30mm in it yet but I expect it to be sharp most of the way to the edge. MN coma correction isn't 100% so that's not a shock. The views really are pleasing through it.

 

Here is a pic of the primary cell I which I put together a while back (I don't have a picture of the secondary holder handy):

 

get.jpg

 

My copy is a couple of years old, but here are my thoughts. First, the mirror clips were way too tight when it arrived. In fact the clips left permanent marks on the mirror. Not a big deal as the clips cover the marks they created, but there was massive pinching/astigmatism due to this. Perhaps they did it for shipping reasons, I'm not sure. What they didn't do is tell me to loosen the clips up a bit, so the first year my views through it were lousy.

 

Second, the springs are a bit on the soft side. Collimation wouldn't even hold when moving the scope from the counter to the mount outside. Replacing the primary springs helped greatly. 

 

Third, the primary adjustment screws have a central grub screw used to lock them in place. Tighten them just a bit too much (and I mean a bit) and the screw in the primary cell will start backing out. You've then got to take it all apart and re-secure the screw on the primary. Some Loctite will rectify this problem but I simply chose to not use the grub screws.

 

Fourth, the center spot was off by several mm so my views were further compromised by this. I ended up respotting it with a Catseye Hotspot.

 

The trick to collimating this scope and keeping the coma-free field well centered is to throw the instructions away. Seriously, the manual that came with mine is for classic Newtonians and make no consideration for primary-corrector alignment. In a classic Newt you're primarily concerned with primary-focuser axial alignment but in an MN you are concerned with corrector-primary-focuser axial alignment. Since the corrector doesn't move, you have to align the primary to it first then modify the secondary/focuser positioning. I had to go through numerous iterations to get it right but once I did the views were very rewarding.

 

It's a perfect scope for widefield browsing on an alt-az mount (goes nicely on my Losmandy AZ8), planetary/lunar/solar views are excellent, and it does really well for imaging. In fact I'll have my ESLCH out on Monday on my AZ8 to share the Mercury transit with the public.

 

Mark

 

 


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#97 David_Ritter

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Posted 02 May 2016 - 06:07 PM

 

Hi David,

 

I see you upgraded the focuser to a feathertouch. Which adapter did you use?

 

Thanks!

Gu

 

 

Hi Gu,

 

Starlight Instruments made a custom adapter for me. I sent them the original base and they measured it and made an adapter ring that fit in the original base.  The ring was the correct size for one of their 2" focusers. The cost was quite reasonable, I forget the exact price but it was about the same as any of the standard base adapters they stock.

 

One other thing, the focuser I selected has only 1.5 inches of travel. This was to keep it at a minimal height for use with a camera and filter wheel. To get to focus with eyepieces I need to use a 2 inch extender.

 

David



#98 Yu Gu

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Posted 03 May 2016 - 07:34 AM

Hi David,

Thanks! I guess they are later selling it as this: http://starlightinst...product_id=431 

 

Could you please pose a photo of your adapter?

 

Clear Skies,

Gu



#99 Yu Gu

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Posted 03 May 2016 - 07:40 AM

When it arrives I will be happy to. Anything in particular you are looking to see? As to performance, I had one before. It performed very well with crisp clean pinpoint stars to the edge of the field. It was very close in performance to my 127 APO which is why it was sold. Too close in performance. I am buying it again because it will be for outreach use and some EAA. I plan to test it with my QSI and Astro Toaster to see if the 814 chip will do as well as the APS-C for near real time observing (NRTO) of DSO.

 

I had a similar experience as you except that the comparison was with a TEC 140ED. On my sample (the first version), the optical correction and surface smoothness was on par with the TEC. The focal length was about the same but the MN has a larger aperture and flatter field. Planetary wise, it's noticeably better than the 140. I could see white spots on Jupiter routinely with MN but not in the 140.  That's the reason why the 140ED was sold.

 

But I was bugged by refractor bugs again later and now I have a TEC 160FL. I've not done any comparison between the two yet but they seem to be comparable in performance.

 

Gu 



#100 David_Ritter

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Posted 03 May 2016 - 05:28 PM

Gu, below is a picture of the focuser and adapter ring.

 

When I ordered the focuser, Starlight Instruments did not have a stock part for adapting to the MN190 so my ring was considered a custom adapter. I would guess that the part you found on their site has been added since I ordered mine. It may be worth checking with Starlight Instruments if you want to verify that the catalog item is the same as the one I have.

 

Also, the product page for the ring you found indicates its for an FTF2020BCR focuser, which has 2 inches of travel.  The focuser I have is an FTF2015BCR, which I think has the same body as the 2020 but only has 1.5 inches of travel. Again, best to contact Starlight Instruments to confirm this.

 

David

 

MN190 Feather Touch Focuser and Adapter Ring
 
Edit: one more thing... the 2" to 1.25" adapter did not come with the focuser. Its a TeleVue adapter that came with one of my PowerMates. I should probably order an adapter for the focuser at some point... but the TV adapter is working fine and the Powermate is safely stored in a plastic bag to keep dust out.
 
Edit2: ok, two more things... this is setup for imaging. The 2 to 1.25 adapter is just acting as a dust cover. For visual use, to get to focus I need a 2 inch extension between the focuser and eyepieces.  But the camera has enough back-focus distance that it works very well without the extension (its a CCD but I've set it up like a DSLR with 55mm back-focus).

Edited by David_Ritter, 03 May 2016 - 05:35 PM.



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