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New Mewlon 180C ?

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173 replies to this topic

#26 vkx86

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Posted 28 October 2016 - 03:41 AM

...especially since it comes with the not-so-hot 6x30 finder.

Found that info:

 

"When people ask me to recommend a good 8X50 finder for their telescopes, I often direct them to this 6X30 unit from Takahashi instead. It's expensive, but worth every penny. Finders from the big companies seem to be getting cheaper and less useful these days. Edge sharpness and good coatings are becoming a distant memory. This Takahashi unit is sharp right out to the edge, and its coatings are excellent. The eyepiece has a generous field of view, and is held on via a compression ring - a nice touch. What's more, the view is almost as bright as any of my 8X50 finders"

 

on scopereviews cite


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#27 Marcsabb

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Posted 28 October 2016 - 07:56 AM

 

...especially since it comes with the not-so-hot 6x30 finder.

Found that info:

 

"When people ask me to recommend a good 8X50 finder for their telescopes, I often direct them to this 6X30 unit from Takahashi instead. It's expensive, but worth every penny. Finders from the big companies seem to be getting cheaper and less useful these days. Edge sharpness and good coatings are becoming a distant memory. This Takahashi unit is sharp right out to the edge, and its coatings are excellent. The eyepiece has a generous field of view, and is held on via a compression ring - a nice touch. What's more, the view is almost as bright as any of my 8X50 finders"

 

on scopereviews cite

 

A little clarification... the Tak 6x30 is not a bad product, but it's nothing like the 7x50 which was packed with the 'B' version of the scope. Considering the price I feel Takahashi cut some corners here.


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#28 Bill Barlow

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Posted 28 October 2016 - 09:33 AM

There is a big difference in using a 30mm vs. 50mm finder scope I would think for someone like me who star hops to their targets.  Images should be noticeably brighter in the 50 compared to the 30.  

 

Bill


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#29 Marcsabb

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Posted 28 October 2016 - 10:53 AM

Indeed, the 7x50 is very bright, courtesy also of the excellent coating.

 

I forgot to add in the other post that the 7x50 finderscope also has an illuminated reticle, one more reason to prefer it to the smaller one.


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#30 vkx86

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Posted 28 October 2016 - 11:21 AM

Probably Takahashi decided to use their entry-level finder on their entry-level Mewlon, as they already did with Mewlon-180A.

Interesting, what was the original price of Mewlon-180B in yen. 

Marcsabb, you mentioned re-coating in your plans - is your Mewlons's mirror's condition after 16 years so bad?


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#31 Marcsabb

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Posted 28 October 2016 - 01:46 PM

Probably Takahashi decided to use their entry-level finder on their entry-level Mewlon, as they already did with Mewlon-180A.

Interesting, what was the original price of Mewlon-180B in yen. 

Marcsabb, you mentioned re-coating in your plans - is your Mewlons's mirror's condition after 16 years so bad?

The equivalent price was 1800$. I don't know if that price included end sales taxes though.

 

Mirros of my tak are not in bad condition but I feel the image is a bit dimmer than it should. Also, the past owner (I bought it used) must have been a kleenex affictionado as there are signs of the mirrors having been wiped with a cloth. You need a flaslight pointed at the primary to see the tiny scratches, but they're there. Other than that, it's in good condition with no stains or any visible defects.



#32 vkx86

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Posted 28 October 2016 - 02:22 PM

Seems Tak pricing level for Mewlon-180 is consistent.

Regarding Tak cutting corners on finder you'd mentioned:

Why did they put bigger finder on 'B' model and then halt Mewlon-180 production for many years?

Looks like Tak got rid from 180's mirror sets they had by throwing bigger finder to help sales.



#33 Marcsabb

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Posted 28 October 2016 - 05:18 PM

Seems Tak pricing level for Mewlon-180 is consistent.

Regarding Tak cutting corners on finder you'd mentioned:

Why did they put bigger finder on 'B' model and then halt Mewlon-180 production for many years?

Looks like Tak got rid from 180's mirror sets they had by throwing bigger finder to help sales.

The 180 is the oldest Mewlon, introduced in 1990. Then came the 250 the next year and then the 300. The 210 arrived in late 1993. The 180B looks like a 210 only a bit smaller and it also got the same M71 to 2" visual back (earlier 180s had a different accessory at the back).

 

The 180 was probably discontinued because, by 2005-2006, the 210 sold more than all the rest of the Mewlon line and its little brother seemed supefluous. Yet many people with whom I have spoken and who have owned both, rate the optics of the 180 as slightly better than the 210; it has always been praised for its fast cooldown time, too.

 

In the previous page there is a picture of a 180 and a 210 side by side; the smaller size of the 180 is readily appreciable, making it a handier scope for people who want to travel light. Used Mewlon 180s are always in great demand so probably Takashi realized ther is still a market for them.


Edited by Marcsabb, 28 October 2016 - 05:23 PM.

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#34 Bill Barlow

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Posted 28 October 2016 - 05:29 PM

Would be nice if Takahashi put a RACI finder on these telescopes instead of the straight thru version.  I had the only straight 6x30 finder on my first SCT, a C6, and found how uncomfortable it is to use one of these when the scope is pointed toward the zenith.

 

Bill



#35 ryderc1

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Posted 28 October 2016 - 07:25 PM

There is a big difference in using a 30mm vs. 50mm finder scope I would think for someone like me who star hops to their targets.  Images should be noticeably brighter in the 50 compared to the 30.  

 

Bill

Partially offseting the smaller aperture is the 6x30 finder's 7.5 degree field of view vs. the 6.2 degrees of  the 7x50.  Having owned and used both finders with scopes on non-driven mounts, I found both to be excellent.


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#36 vkx86

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Posted 29 October 2016 - 12:07 AM

Would be nice if Takahashi put a RACI finder on these telescopes instead of the straight thru version. 

Probably the issue can be addressed with that 90 degree viewer for polar finders.

Also I'd noticed that Tak has no angled finders in their lineup (or maybe I missed them).


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#37 Bill Barlow

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Posted 29 October 2016 - 09:22 AM

It doesn't say that it will fit a Tak finder scope.  Plus from what I remember, polar alignment prisms like this one have the star field backwards, so not much use for visual star hopping.

 

Bill


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#38 vkx86

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Posted 29 October 2016 - 10:34 AM

It doesn't say that it will fit a Tak finder scope.  Plus from what I remember, polar alignment prisms like this one have the star field backwards, so not much use for visual star hopping.

 

Bill

I think that if connection cup of that viewer is larger, than Tak finder's ocular housing - then it can be fitted with little DYI: 

a strip of plastic rolled into ring inside connection cup should do the trick.

That viewer has Amici prism, so finder view orientation will be intact.


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#39 Bill Barlow

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Posted 29 October 2016 - 06:41 PM

Okay, we'll that's good as I didn't know that.  But a 30mm finder seems too small for what I need one for.  A 50mm will go much deeper, especially in a light polluted area.

 

Bill



#40 vkx86

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Posted 30 October 2016 - 12:42 AM

But a 30mm finder seems too small for what I need one for. A 50mm will go much deeper, especially in a light polluted area.

Bill


Seems that finder is a show-stopper...
Maybe better that Tak should continue with 7x50 finder - the difference is small (~150 USD?).
On the other hand, it's mainly a planetary scope and that 6x30 finder should be enought to find planets, in my opinion.

#41 Max Power

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Posted 30 October 2016 - 11:03 AM

Anybody who doesn't buy a scope because of a easily replaceable item probably can't afford it anyway.
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#42 Bill Barlow

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Posted 30 October 2016 - 04:29 PM

Unfortunately it doesn't look like it is easy to replace these Tak straight through finders.

 

Bill



#43 payner

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Posted 30 October 2016 - 07:59 PM

And my guess is impossible if using the factory bracket that is built into the telescope. Other cassegrain Taks I've had the diameter would negate a larger diameter than what was designed and cast by Tak.

 

Randy



#44 vkx86

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Posted 31 October 2016 - 12:01 AM

I don't think finder housing is cast as a whole with the base. It most probably connected by screws from inside that big cast ring that main mirror assembly connected to with three screws.

Tak maybe offer upgrade later.

In any case, one can drill and tap two holes in that cast ring and put regular finder shoe there.

It's half-hour DIY that will solve the problem for some folks.


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#45 Max Power

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Posted 31 October 2016 - 09:13 PM

I removed one of the back end screws and put a one hole finder shoe on. Hate straight thru finders.
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#46 vkx86

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Posted 02 November 2016 - 02:35 AM

Marcsabb, what is the widest FOV you can get from your Mewlon?

#47 Marcsabb

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Posted 02 November 2016 - 07:01 AM

I've never calculated it; I can tell you that it has a roughly a 15-16mm image circle without the corrector / reducer.


Edited by Marcsabb, 02 November 2016 - 07:02 AM.


#48 vkx86

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Posted 02 November 2016 - 11:24 AM

I've never calculated it; I can tell you that it has a roughly a 15-16mm image circle without the corrector / reducer.

From that drawing:

schemamewlon1.jpg

can you please tell me primary mirror baffle minimal internal diameter? - That is where the baffle connects to primary mirror cell.


Edited by vkx86, 02 November 2016 - 11:31 AM.


#49 Marcsabb

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Posted 02 November 2016 - 05:48 PM

I don't have a suitable caliber at hand to measure it, but, from a quick visual inspection, the rear port in the primary cell is a bit larger than a 2" barrel. I've swapped the default visual back for a large Baader Clicklock made for other Takahashi scopes. To mate it to the rear cell, a M71 to M72 adapter is needed as the Mewlons employ a different flange.

I also found the original datasheet I had saved from Takahashi Europe mirror site, when the Mewlon was still on sale, and I can confirm that the fully illuminated image circle is 16mm for the 180 and 18mm for the 210.
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#50 vkx86

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Posted 02 November 2016 - 11:36 PM

...from a quick visual inspection, the rear port in the primary cell is a bit larger than a 2" barrel...

...I can confirm that the fully illuminated image circle is 16mm for the 180...

Larger than 2"? You maybe mean larger than 1.25"?

From that Mewlon-180C photo (I don't think that was changed from your Mewlon-180B) it looks like it is maybe a bit larger than 1.25" but smaller than 2":

 

m180cb.jpg

 

I don't know how to convert fully illuminated circle to scope's max FOV (is that possible?). I want to calculate scope's max FOV by restricting barrel - looks that in Mewlon's case it's primary mirror baffle rear opening (if it larger than 1.25").


Edited by vkx86, 02 November 2016 - 11:56 PM.

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