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Skywatcher Equinox 66ED APO Astrograph for DSLR?

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#1 Falcon-

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Posted 06 October 2009 - 12:59 AM

After getting advice to go with a small refractor as an AP telescope for my CG-5 mount and Canon XT (the AT66ED and WO Zenithstar 66ED were mentioned by forum members as examples).

After reading
jmX's post about his new Equinox 80 I did some searching and see that SkyWatcher also makes a 66mm scope that they call an "astrograph" and specifically claim flat fields for, as they do for the 80mm that jmX is using.

Given I had been specifically warned I would need a field flattener for the other two scopes this makes the SkyWatcher 66 apo very appealing - if not quite believable. I notice though that it is a 1.25" focuser rather then a 2" focuser as seen on most other scopes and wonder if I would get vignetting on a DSLR with an APS-C sized sensor such as my 350D with this scope. I also wondered just how far their Astrograph/Flat-field claims go.

As it stands right now the Equinox 66ED APO Astrograph sure looks like an excellent first AP-specific scope purchase! Do you have any experience that says otherwise?

Thanks :bow:

- Sean

#2 Nils_Lars

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Posted 06 October 2009 - 01:15 AM

I would always recommend something like this as a first AP scope , I got by for a long time with just an ED80 and there are a lot of targets that can be done well.

#3 Falcon-

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Posted 06 October 2009 - 01:34 AM

sure, but what I really wonder is if, in comparison to those other small refractors of the same price range, the Skywatcher Equinox is actually going to provide a flatter field without the use of a field flattener. Right now I am trying to chose between the Equinox 66ED, the AT66ED and the WO Zenithstar 70ED - if the equinox REALLY has a flatter field then it probably wins.

#4 David Rosenthal

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Posted 06 October 2009 - 06:29 AM

I shot through a 66SD and a DSLR and the field was real bad with out the flattener. I used a WO 0.8X FR/FF with it and it was much better than with out.

#5 RogerRZ

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Posted 06 October 2009 - 06:38 AM

I'd like to add that my 66 Equinox had the nasty lens spacer issue. No problem with visual, but as soon as I strapped a camera to is, I got quite a bit of diffraction which is, in my opinion, not acceptable in an "imaging refractor"..

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#6 Stardaug

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Posted 06 October 2009 - 06:52 AM

You'll still need a field flattener/reducer most likely. I originally bought a Equinox 66mm and it had the lens spacer issue noted by Roger. Created negative defraction spikes when imaging. Seems there was a number of them out there afflicted with this problem. I returned it and upgraded to the 80mm ED and it works great, visually and imaging.

#7 Clay Kessler

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Posted 06 October 2009 - 09:11 AM

The only thing that would frighten me is the 1.25" focuser. How much less expensive is it in comparison to the others?

#8 Falcon-

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Posted 06 October 2009 - 12:16 PM

Clay - It is all of an entire $4usd less expensive then the AT66ED and $43 less then the WO ZS 66ED. The 1.25" focuser made me wonder as well, but if it did not need a field flattener it would be quite a lot less expensive since I do not yet own one. From the sounds of the experience Stardaug and RogerRZ had that is not the only worry with that scope... leaning me back towards the AT66ED + flattener.

Stardaug - can I assume you use a field flattener with your equinox 80ed? If so, what one?

#9 jmX

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Posted 06 October 2009 - 12:32 PM

My advice is get something that is a proven combo, something you can see full uncropped images from to make sure most of the frame is actually usable. I never saw any good photos from the Equinox 66, but I guess I didn't look very hard. Just about everything is going to require a field flattener, and all flatteners are 2", not 1.25", so stay away from the scopes with 1.25" focusers.

http://www.weatherandsky.com/ uses the EQ80 scope with a flattener, as I and many others do, and I think it might be one of the cheapest proven setups out there.

#10 Falcon-

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Posted 06 October 2009 - 12:42 PM

jmX - sound advice. What flattener do you use with your EQ80?

#11 Jimmy2K63

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Posted 06 October 2009 - 12:55 PM

SO are you saying something like the AstroTech AT66ED would be more suitable to use as an imaging scope?

#12 David Rosenthal

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Posted 06 October 2009 - 02:43 PM

Here is a UNCROPPED shot using a DSLR + 66SD + WO 0.8X FR/FF Type II. AS you can see, the corner stars are round, but, FWHM is higher than the center. Pretty good results from a inexpensive combo!

http://www.pbase.com...image/106520695

#13 jmX

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Posted 06 October 2009 - 02:52 PM

jmX - sound advice. What flattener do you use with your EQ80?


I use the televue 0.8x flattener. I also picked up a much cheaper astrotech 1.0x flattener, but have not tried it yet. The televue worked fantastically, but is pricey and cuts my 500mm focal length to 400mm. The september shots on my website are all Equinox80+TV 0.8x flattener at 400mm f/5.

Keep in mind that some of the williams optics flatteners might be harder to find now, as they've moved from California to Taiwan recently and it seems like they want to sell direct to the customer from taiwan. A few places still have some of their stuff in stock, but if you pick a scope that wants a WO flattener, make sure you can find one before you order the scope.

#14 Stardaug

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Posted 06 October 2009 - 05:28 PM

Stardaug - can I assume you use a field flattener with your equinox 80ed? If so, what one?


I'm using a Televue 0.8x FF/FR with the Equinox 80mm ED. Very nice combo. Without the FF/FR I have egg shaped stars in the corners but I usually just crop that out anyhow.

#15 buc240

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Posted 06 October 2009 - 05:29 PM

No matter which of the mentioned scopes you would like to purchase they will ALL require a Flattner/Reducer or Flattner to achieve an acceptably flat field across the frame when using the large chip of a DSLR, The Televue trf2008 0.8 FF/FR will work well with all of the mentioned scopes, but in experience the WO 0.8 II will not work as good with some, my reccomendation would be to buy the original ED80 from Orion and purchase either the WO II if you can locate it or better yet the trf2008, the ED80 is a time proven performer with an ideal focal length with reducer @ 480mm and F/6 and will produce a nicely flat field with either flattner reducer. The smaller 66mm scopes will not yield as flat a field as the ED80 with a DSLR chip and one of the mentioned reducers, another very sound option would be the newer Stellarvue SV70ED very well color corrected optics and works great with the trf2008 and is priced very affordable, I would choose the SV70ED and trf2008 as my first choice and the ED80 as the second.......my 2 cents

#16 Falcon-

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Posted 07 October 2009 - 03:12 AM

I also picked up a much cheaper astrotech 1.0x flattener, but have not tried it yet.


jmX - I would love to hear how the Astrotech 1.0x flattener works for you with that scope! Please do post once you get a chance to use it.

#17 Nils_Lars

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Posted 07 October 2009 - 03:07 PM

I bought my ED80 used and had the lens spacer issue also but I found a guide on Andys shotglass that showed how to pull the spacers out and cut 2/3 of them off and put back and it took care of that problem.






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