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New Mewlon 180C ?

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#76 vkx86

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Posted 20 January 2017 - 04:31 AM

Still waiting......

Baby-μ worth waiting, your patience will be greatly rewarded ;-)


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#77 etsleds

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Posted 23 January 2017 - 02:51 AM

Re: baffle tube inner diameter, I measured mine around 33mm. The fall-off is really evident in wide pieces like a 21mm Ethos or 31mm Nagler and coma makes what you can see unpleasant when you're that wide anyway. I just considered mine to be a 1 deg view tops and was pretty happy with it.

 

It's a light, easy to balance, dew-free, good contrast, reasonable aperture scope. Sold it for the perverse reason that it was such reasonable performance in a handy package that I used it more than any of my other scopes...seriously. My other scopes were a bit less balanced in attributes, but better in one or more ways.

 

Contrast is indeed good, but refractor-like? It's not magic, it has a 33% measured central obstruction and you see that in steadiness of seeing and contrast. It's really well-executed and the DK design has a great central spot size, it's probably one of the best performing 33% CO scopes out there.

 

I agree it should sell well and I think it would be great "only" scope in this price range.


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#78 The Ardent

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Posted 24 January 2017 - 06:58 PM

I'm thinking about a TSA120 instead of the Mewlon. 

 

Still waiting......

Baby-μ worth waiting, your patience will be greatly rewarded ;-)

 


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#79 vkx86

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Posted 25 January 2017 - 12:39 AM

 

...it has a 33% measured central obstruction and you see that in steadiness of seeing and contrast. 

 

How central obstruction affects steadiness of seeing?


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#80 vkx86

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Posted 25 January 2017 - 01:08 AM

 

I'm thinking about a TSA120 instead of the Mewlon. 

After 3 months with Mewlon, I don't regret my decision (I also considered 120mm APO - ED120) to get a dedicated Lunar and planetary scope (I'm 99% Lunar and planetary observer).

My ED80 and Mewlon-180 are good tandem under my LP urban sky, with ED80 taking ~ 80% of use, as tester of seeing conditions (winter is not a good season for stable seeing in my location, I will see how this ratio will be in spring-summer-autumn).


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#81 Seiko4169

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Posted 25 January 2017 - 08:08 AM

 

I'm thinking about a TSA120 instead of the Mewlon. 

 

Still waiting......

Baby-μ worth waiting, your patience will be greatly rewarded ;-)

 

 

IMHO the TSA 120 is the much better all rounder. The Mewlon though (well my 210) goes deeper making targets easier to see. If I could have only 1, the TSA 120. Its just an amazingly versatile all rounder with incredible optics, low weight and small foot print.

 

Based on your other scopes and intended targets you may want to consider the TSA 120.


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#82 bobhen

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Posted 25 January 2017 - 08:28 AM

 

 

I'm thinking about a TSA120 instead of the Mewlon. 

 

Still waiting......

Baby-μ worth waiting, your patience will be greatly rewarded ;-)

 

 

IMHO the TSA 120 is the much better all rounder. The Mewlon though (well my 210) goes deeper making targets easier to see. If I could have only 1, the TSA 120. Its just an amazingly versatile all rounder with incredible optics, low weight and small foot print.

 

Based on your other scopes and intended targets you may want to consider the TSA 120.

 

Agree.

 

I also have a 210 and TSA 120. If I “had” to choose one, it would also be the TSA 120, and for all the reasons stated.

 

But the Mewlon 210 does go deeper, has obviously better contrast than any SCT, and will deliver more lunar/planetary detail. However, all Cassegrains are more fussy with seeing and temperature acclimation so the seeing has to be above average (more rare at my location than I would like) for the Mewlon to deliver to its potential on the moon and planets. But when it does, the views are really sharp and detailed.

 

I’m fortunate that I don’t have to choose, as the two they make a great combination, as one of the two scopes will usually be perfect for the conditions and the object of observation.

 

Bob


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#83 etsleds

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Posted 26 January 2017 - 04:57 PM

It's been my experience that my obstructed scopes show stronger fluctuation in image during unsteady seeing than my unobstructed scopes, for the same primary aperture. There's been various this and that said here and elsewhere about this, seems to be good technical basis for what I'm seeing.

 

 

 

...it has a 33% measured central obstruction and you see that in steadiness of seeing and contrast. 

 

How central obstruction affects steadiness of seeing?

 

 

Agreed, the TSA120 is another stellar and well-balanced choice for one all-rounder scope, trading off light collection & resolution for a sharper image.

 

 

 

 

 

I'm thinking about a TSA120 instead of the Mewlon. 

 

Still waiting......

Baby-μ worth waiting, your patience will be greatly rewarded ;-)

 

 

IMHO the TSA 120 is the much better all rounder. The Mewlon though (well my 210) goes deeper making targets easier to see. If I could have only 1, the TSA 120. Its just an amazingly versatile all rounder with incredible optics, low weight and small foot print.

 

Based on your other scopes and intended targets you may want to consider the TSA 120.

 

Agree.

 

I also have a 210 and TSA 120. If I “had” to choose one, it would also be the TSA 120, and for all the reasons stated.

 

But the Mewlon 210 does go deeper, has obviously better contrast than any SCT, and will deliver more lunar/planetary detail. However, all Cassegrains are more fussy with seeing and temperature acclimation so the seeing has to be above average (more rare at my location than I would like) for the Mewlon to deliver to its potential on the moon and planets. But when it does, the views are really sharp and detailed.

 

I’m fortunate that I don’t have to choose, as the two they make a great combination, as one of the two scopes will usually be perfect for the conditions and the object of observation.

 

Bob

 


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#84 plyscope

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Posted 26 January 2017 - 05:53 PM

Don't forget that the TSA 120 costs twice as much as a Mewlon 180!


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#85 vkx86

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Posted 27 January 2017 - 12:52 AM

 

It's been my experience that my obstructed scopes show stronger fluctuation in image during unsteady seeing than my unobstructed scopes, for the same primary aperture. There's been various this and that said here and elsewhere about this, seems to be good technical basis for what I'm seeing.

Both were closed tube-scopes, e.g. Frac and Mak?

Maybe  you mean open-tube scope (Cass, Newt) vs closed tube? - I noticed that wind gust affects open-tube scope's image since I'd owned 130-mm Sky-watcher mini-dob.



#86 etsleds

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Posted 27 January 2017 - 03:37 AM

No, I mean obstructed vs non-obstructed. Been my experience with Maks, SCTs, DKs, Newts vs apos...never had an off-axis reflector to try.

 

As I said, there's a lot been said on this, a quick Google search pulls up:

 

http://www.csun.edu/...n/tmb/tmb2.html

http://www.cloudynig...al-obstruction/

https://groups.googl...yE/0L_Od-ORz4AJ

 

I sort of came at this from the opposite direction, noticing it happening in my scopes and digging into why that might be.

 

 

 

 

It's been my experience that my obstructed scopes show stronger fluctuation in image during unsteady seeing than my unobstructed scopes, for the same primary aperture. There's been various this and that said here and elsewhere about this, seems to be good technical basis for what I'm seeing.

Both were closed tube-scopes, e.g. Frac and Mak?

Maybe  you mean open-tube scope (Cass, Newt) vs closed tube? - I noticed that wind gust affects open-tube scope's image since I'd owned 130-mm Sky-watcher mini-dob.

 


Edited by etsleds, 27 January 2017 - 03:47 AM.


#87 Fomalhaut

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Posted 27 January 2017 - 05:37 AM

I also have a 210 and TSA 120. If I “had” to choose one, it would also be the TSA 120, and for all the reasons stated.
 
Bob


I also have a Mewlon-180 and FCT100. And if I had to choose one, it would be the FCT100, and also for all the reasons stated.
IOW, I fully agree...

Chris

#88 vkx86

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Posted 27 January 2017 - 06:28 AM

 

No, I mean obstructed vs non-obstructed. Been my experience with Maks, SCTs, DKs, Newts vs apos...never had an off-axis reflector to try.

 

As I said, there's a lot been said on this, a quick Google search pulls up:

 

http://www.csun.edu/...n/tmb/tmb2.html

http://www.cloudynig...al-obstruction/

https://groups.googl...yE/0L_Od-ORz4AJ

 

I sort of came at this from the opposite direction, noticing it happening in my scopes and digging into why that might be.

 

Andrew, thanks for good direction on investigation!

 

I still prefer larger than 120mm aperture scope at my disposal on nights of good seeing - more Lunar and planetary details at price of some contrast loss (In case of Moon, my primary target, I doubt, that I can detect much difference in my Fovea centralis).

 

I would say, that potential Mewlon-180 buyers should evaluate their seeing conditions before hitting the "Purchase" button. And in my opinion, it come at excellent price-point for such a sharp optics in a compact & fast-acclimating package, better price-wise than larger than 80mm APOs.


Edited by vkx86, 27 January 2017 - 09:51 AM.


#89 plyscope

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Posted 02 February 2017 - 01:25 AM

My Mewlon 180C arrived yesterday. For some reason it took 12 days to get from the dealer in South Australia to me in Western Australia. It arrived safely though and I was even able to get a quick first light last night.

 

Despite poor seeing and high humidity I was impressed with the views. The moon was low and not at it's best. Orion was a better target and the Trapezium was fantastic. Stars E and F were visible. Collimation appears to be good though I will need better seeing to confirm. The finder scope alignment was good as delivered. Looking forward to spending more time with this new scope. It fits well with the Vixen GPD2 mount.

 

So far I like the light weight and compact design. I like the built in finder scope that acts as a handle. This is my first Cassegrain reflector.

 

IMG_0378 - Copy.JPG

 

IMG_0380 - Copy.JPG

 

IMG_0381 - Copy.JPG


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#90 plyscope

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Posted 02 February 2017 - 01:27 AM

More pictures.

 

IMG_0383 - Copy.JPG

 

IMG_0388 - Copy.JPG


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#91 bobhen

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Posted 02 February 2017 - 08:16 AM

For high power viewing, give that Mewlon 180 time to acclimate and make sure collimation is dead on and you will be rewarded with very sharp views.

 

I think you will also enjoy deep-sky viewing, as the Mewlons (for Cassegrains) all have really excellent contrast.

 

Enjoy.

 

Bob


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#92 Bill Barlow

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Posted 02 February 2017 - 10:41 AM

Andy, congrats on the new M180.  The tube paint finish looks a different shade of white when compared to your Tak refractors.  Enjoy the Mewlon.

 

Bill


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#93 vkx86

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Posted 02 February 2017 - 12:45 PM

Despite poor seeing and high humidity I was impressed with the views. The moon was low and not at it's best. Orion was a better target and the Trapezium was fantastic. Stars E and F were visible. Collimation appears to be good though I will need better seeing to confirm. The finder scope alignment was good as delivered. Looking forward to spending more time with this new scope. It fits well with the Vixen GPD2 mount.

 

Congrats! You will be amazed by Lunar and planetary views, that Mewlon-180 renders in good seeing...I am ;-)


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#94 plyscope

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Posted 02 February 2017 - 04:28 PM

Andy, congrats on the new M180.  The tube paint finish looks a different shade of white when compared to your Tak refractors.  Enjoy the Mewlon.

 

Bill

Hi Bill, yes it is a cream colour. It goes well with the new pale blue.


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#95 The Ardent

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Posted 02 February 2017 - 04:33 PM

Still waiting... now with envy and angst

#96 Bill Barlow

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Posted 02 February 2017 - 05:01 PM

How much does the M180 weigh?

 

Bill



#97 plyscope

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Posted 02 February 2017 - 11:50 PM

It weighs 6.2 kg.

 

http://www.astronomy..._mewlon180c.htm


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#98 vkx86

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Posted 03 February 2017 - 12:16 AM

Andy, if you plan more equipment photo sessions - it would be interesting to see a shot of Baby-Mu next to 6" f15 D&G  ;) 



#99 plyscope

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Posted 03 February 2017 - 08:11 AM

Eventually I will try to compare them directly. The Mewlon 180 is less than half the weight and one third of the length. I don't consider the D&G to be portable and have only ever used it in the back yard. It will be fun to compare the views.


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#100 Bill Barlow

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Posted 03 February 2017 - 11:05 AM

I would be interested on how the M180 compares to your TSA102, especially on planets.  I would think the M180 will outperform the Mewlon on deep sky targets.   What is the CO of the M180?

 

Bill


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