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Reducer for AT72EDII

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22 replies to this topic

#1 saptharishi

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Posted 24 July 2019 - 01:25 AM

Hi Friends,

 

I am planning to buy a 0.8x reducer for AT72EDII scope.  I see the following options, and the prices are different:

 

- Tele Vue 0.8X Reducer/Flattner for 400-600mm Refractors. (Televue TRF-2008 0.8x Reducer/Flattener)

- Astro-Tech 0.8x Reducer/Field Flattener for F/6 Refractors

- Orion 8894 0.8x focal reducer for refractor telescopes

 

Any thoughts on which one would be the versatile.  Televue TRF-2008 is double the price of the the other two options.  Does it worth spending the money on Televue TRF-2008.  Please let me know your thoughts.  If any of you have used these reducers or compared them, please post your experience. Thanks in advance.



#2 james7ca

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Posted 24 July 2019 - 01:59 AM

Do you plan on trying to use this for visual work? If so, that may not work that well since the backfocus is limited to something near to 55mm (probably for all of these). Thus, it may not come to focus with a 2" diagonal. I don't know, maybe you could place it after the diagonal but then the scope might not have enough focus travel.

 

See here for the optical path length for various diagonals:

 

  https://www.cloudyni...omparison-r2877

 

However, for imaging I'd just go for the Astro-Tech 0.8X reducer. The Tele Vue MIGHT produce better results, but unless you try both you'll probably have no way to know for sure (unless someone else has already done that testing with the AT72EDII).



#3 saptharishi

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Posted 24 July 2019 - 03:07 AM

Thanks so much James7ca.  I do you it for visual,  but I will remove the reducer while doing visual astronomy. Reducer is only for the imaging. 



#4 tonyt

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Posted 24 July 2019 - 05:31 AM

This scope is very fussy about reducers; I'd ask Astronomics for a recommendation - you may be better off with a flattener.



#5 saptharishi

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Posted 24 July 2019 - 06:24 AM

Hi Tonyt, When you say, it is a bit fussy, I guess you had some bad experience using the scope with the reducer.  Can you share your experience.Thanks a lot.



#6 tonyt

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Posted 24 July 2019 - 07:00 AM

I had the TS version of the scope and it didn't work well with the TS .8 reducer or the WO 6AII reducer. The 70mm f/6 triplets seem to work better with reducers. I guess more aberrations can be better corrected in the outer field with the extra element. In any case I suggest you don't buy a reducer until you can confirm that it works with your scope.



#7 Ed D

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Posted 24 July 2019 - 07:28 AM

I have used my ATR8 Astro Tech .8x reducer/flattener for a few years with my AT72ED and have gotten very good results.  Cameras used were my ASI290MC and Canon T3i.  No experience with any of the other equipment you listed.

 

Ed D


Edited by Ed D, 24 July 2019 - 07:28 AM.

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#8 johrich

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Posted 24 July 2019 - 08:46 AM

I also have used the ATR8 with my AT72EDII and have been happy with the results.  I use it with an ASI183MC cool and Canon SL1.

 

johrich



#9 kolsen

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Posted 24 July 2019 - 08:58 AM

FYI the ATR8 has been on backorder since January.  Astronomics says it probably won't be delivered until October.



#10 saptharishi

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Posted 25 July 2019 - 01:55 AM

Good to know that ATR8 works well with AT72EDII.  Given that the Televue version should also work with AT72EDII, since it is readily available I am tilted towards it.



#11 krockelein

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Posted 30 January 2020 - 12:18 AM

Has anyone heard when the .8 reducer/flatteners for the AT72EDII will be in?  I emailed through the astronomics link, but haven't gotten a response back yet.


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#12 LPA

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Posted 30 January 2020 - 10:16 PM

Has anyone heard when the .8 reducer/flatteners for the AT72EDII will be in?  I emailed through the astronomics link, but haven't gotten a response back yet.

I was told by them that the FF/FR's are being manufactured now and will be shipped to them via air freight. No date though. In the meantime, I've gotten good results using the TV85 0.8x FF/FR, but the AT FF/FR will have threaded connections to the camera and AT72EDII, which I prefer.

 

Larry


Edited by LPA, 30 January 2020 - 10:16 PM.

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#13 krockelein

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Posted 31 January 2020 - 12:36 AM

Thanks, Larry. Well, it looks likely then that I’ll have to put aside plans to image the Horsehead and Flame or any other large target this winter. I get too much aberration around the outside with my ASI1600 without a flattener/reducer, and I don’t have the benjamins to buy another one in the interim. I agree with you about the threaded ends, though. 



#14 Don W

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Posted 31 January 2020 - 01:16 PM

I have had one on order since April of last year.


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#15 Odin Exodus

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Posted 31 January 2020 - 03:05 PM

Not to divert the conversation, but I have classifieds posted despite placing orders through Astronomics for the reducer/flattener to use with the AT72 and AT130. Surprised they didn't come with the last shipment of scopes..  At this point, I'll take what I can get.  I scooped the Orion 8894 on classifieds but haven't had a chance to take it out for a spin (gray skies for the last month+). My one concern is that it is only a reducer and isn't labeled as a flattener. Would this affect the quality of the image? And if so, that may eliminate 1 out of your 3 options.  I'll try and get out on a clear night and report back with any findings.



#16 krockelein

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Posted 02 February 2020 - 11:32 AM

Don, seriously?  Since April?  Ok, this is my first time making purchases from Astronomics and I really hope it's not indicative of the normal experience.  My frustration level is rising as I just bought the AT72EDII and the FF specifically for imaging some large nebulae, and now the window of opportunity for capturing my targets is passing for the year.



#17 Chilihead

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Posted 02 February 2020 - 03:24 PM

Don, seriously?  Since April?  Ok, this is my first time making purchases from Astronomics and I really hope it's not indicative of the normal experience.  My frustration level is rising as I just bought the AT72EDII and the FF specifically for imaging some large nebulae, and now the window of opportunity for capturing my targets is passing for the year.

I'm guessing this has a lot to do with tariff issues, not with Astronomics. 


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#18 krockelein

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Posted 02 February 2020 - 07:02 PM

Oh, that's a very good thought that I hadn't considered.  Thank you for suggesting it.



#19 RaulTheRat

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Posted 02 February 2020 - 07:43 PM

This scope is very fussy about reducers; I'd ask Astronomics for a recommendation - you may be better off with a flattener.


I'm with this, couldn't get a reducer to work well (only tried one, the TS 0.8x) and went with a plain flattener which is good.

#20 LPA

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Posted 03 February 2020 - 09:29 AM

Don, seriously?  Since April?  Ok, this is my first time making purchases from Astronomics and I really hope it's not indicative of the normal experience.  My frustration level is rising as I just bought the AT72EDII and the FF specifically for imaging some large nebulae, and now the window of opportunity for capturing my targets is passing for the year.

If you don't want to wait, get the TV85 FF/FR. I posted images with this reducer on my AT72EDII here:

https://www.cloudyni...-with-at72edii/

 

Larry



#21 saptharishi

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Posted 09 February 2020 - 10:57 AM

If you don't want to wait, get the TV85 FF/FR. I posted images with this reducer on my AT72EDII here:

https://www.cloudyni...-with-at72edii/

 

Larry

Hi Larry, I guess you are referring to Televue TRF-2008 0.8x Reducer/Flattener, right?


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#22 LPA

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Posted 09 February 2020 - 12:43 PM

Yes, that is the one I used for those images. There is very slight distortion at the extreme image corners, otherwise correction is very good. Here is the link to an uncropped, full-size image of the Horsehead and Flame taken with my Pentax K3ii + TV0.8x + AT72EDII:

http://www.remotesen...ead_ABE_HTc.jpg

 

Larry


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#23 saptharishi

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Posted 12 February 2020 - 02:37 AM

Beautiful! I am also planning to get the TV FF/reducer as the AT version does not seem to be available.  Thanks for much for the sharing your experience with TV0.8x, Larry.




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