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Reducer for Tak Mewlon 180

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#1 bdg

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Posted 19 June 2019 - 12:40 AM

I am planning to use Mewlon 180 for NV (visual) - need a reducer faster than Takahashi’s Mewlon compatible  0.8x reducer. Any idea if Celestron 0.6x reducer or something generic works.



#2 chemisted

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Posted 19 June 2019 - 06:19 AM

Have you considered the Astro-Physics CCDT67?



#3 bobhen

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Posted 19 June 2019 - 06:44 AM

I use an Antares .7 2" reducer ($89) with my NVD Micro and Mewlon 210. Don't get the 2" .5 there is too much edge distortion. Got my from Scopestuff.

 

HERE is a link.

 

Bob


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#4 bdg

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Posted 19 June 2019 - 08:42 AM

Have you considered the Astro-Physics CCDT67?

I looked at it but didn’t know if it works for visual. 



#5 chemisted

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Posted 19 June 2019 - 03:20 PM

I looked at it but didn’t know if it works for visual. 

It should work just fine.  It's only requirement is to have a heathy focal ratio.  I have used mine visually with my f/9.3 OGS RC-10 and NVD Micro and it worked great with pinpoint stars throughout the FOV.



#6 Gavster

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Posted 19 June 2019 - 04:47 PM

Will you also be using your c11 edge with the nv monoculars? My c11 edge with the 0.7x edge reducer is one of my favourite nv scopes.



#7 bdg

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Posted 19 June 2019 - 07:22 PM

It should work just fine.  It's only requirement is to have a heathy focal ratio.  I have used mine visually with my f/9.3 OGS RC-10 and NVD Micro and it worked great with pinpoint stars throughout the FOV.

Thanks, I think its inexpensive enough to give a try, figuring out the spacing could be challenging.

 

Will you also be using your c11 edge with the nv monoculars? My c11 edge with the 0.7x edge reducer is one of my favourite nv scopes.

Not sure due to portability issues. I don’t have edge 11 reducer either.


Edited by bdg, 19 June 2019 - 07:23 PM.


#8 chemisted

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Posted 19 June 2019 - 08:09 PM

I don't have the Tak so I cannot comment exactly but I wouldn't worry about the spacing very much.  The key thing with these reducers and NV is will they come to focus.  I have fixed mirrors on my RC-10 and, while the backfocus of the instrument is quite good, these NV devices suck up a lot of backfocus and are troublesome in that regard sometimes.  My configuration was to screw the CCDT67 onto my Baader BBHS silver T-2 diagonal with a 2" to T-2 thin adapter and then use a T-2 to C-mount adapter for the NVD Micro connection.  This worked well as far as coming to focus is concerned.  I may not have achieved the full .67X reduction but I think I came pretty close.


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#9 bdg

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Posted 21 June 2019 - 02:45 PM

I don't have the Tak so I cannot comment exactly but I wouldn't worry about the spacing very much.  The key thing with these reducers and NV is will they come to focus.  I have fixed mirrors on my RC-10 and, while the backfocus of the instrument is quite good, these NV devices suck up a lot of backfocus and are troublesome in that regard sometimes.  My configuration was to screw the CCDT67 onto my Baader BBHS silver T-2 diagonal with a 2" to T-2 thin adapter and then use a T-2 to C-mount adapter for the NVD Micro connection.  This worked well as far as coming to focus is concerned.  I may not have achieved the full .67X reduction but I think I came pretty close.

just ordered CCDT67, is there any difference where the reducer is inserted in the optical train i.e. before or after diagonal .



#10 chemisted

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Posted 21 June 2019 - 04:59 PM

Before the diagonal (close to the NV device) will give a smaller reduction.  The arrangement that I described will probably get pretty close to 0.67X.  I also have the GSO 0.75X reducer claimed to be for RCs but I have used it very successfully with my two refractors when used in afocal mode with the TV 55mm Plossl.


Edited by chemisted, 21 June 2019 - 07:06 PM.



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