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Help me pick my next telescope to complement my widefield ED80...

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#1 canyonblue737


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Posted 01 August 2020 - 11:56 AM

I've fortunately gotten better at imaging this year by leaps and bounds with my ES ED80 FCD100. Right now I'm making very satisfying images finally that I'm continuing to learn how to process better. I use ASIAir Pro along with guiding and electronic focus and everything is working well. I am interested in a counterpart to my widefield scope (I *really* don't intend to have more than 2 scopes at a time) as my next "big" purchase either this fall or spring of next year so I am curious what everyone's thoughts are. As for my widefield setup I don't intend to upgrade my ED80 for a few years, but I do wish it had a tiny bit more focal range and that I could get slightly more of a flatter field (I've done my best and about 90% of the image is flat now) so maybe a few years down the line something like a SkyWatcher Esprit 100 APO is in the cards.

That said...


I'm thinking Celestron EdgeHD 8 with the .7 reducer and an OAG. The focal length will obviously be significantly more that my ED80, with an OAG it should prove to work well with my iOptron CEM40 mount (I have an ZWO 174MM Mini ideal for SCT OAG guiding) and I'll certainly be able to hook it to a laptop for avi capture and planetary work too. I started in all this 5 years ago with a C8 SCT that I don't have anymore and I have a soft spot for the SCT design but I know like everything it has compromises. Do you think going to an SCT is the right choice? 480mm on my ED80 f/6, 1422mm on an EdgeHD f/7 with .7 reducer, 2032mm on the EdgeHD f/10 with no reducer for planetary. That should give a nice blend that lets me do everything from widefield DSO to galaxies and globular clusters to planets right?

Any other ideas for a 2nd scope that isn't an SCT and would work with my existing CEM40 mount? Thanks!

#2 SilverLitz


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Posted 01 August 2020 - 12:23 PM

EdgeHD 800 w/ 0.7x FR seems like a very good compliment, and probably as long as you will want to go with your CEM40.  With FR it will give you a 0.67"/px image scale with a 294, which should be nicely sampled for 3" or better seeing.


I have an Esprit 100, that I use at both native 550mm and 413mm w/ 0.75x, doing most at 413mm.  I added an EdgeHD 925 w/ 0.7x FR as my galaxy scope, but I have the more robust G11 as my mount.  I am currently imaging on the small pixel ASI183mm-Pro, which is clearly oversampled with the Edge, but seems to work well with my 1.5" typical seeing.  I plan on adding an APS-C camera when something like a mono ASI2600 becomes a reality, which should be an ideal fit for my EdgeHD 925.

Edited by SilverLitz, 01 August 2020 - 12:24 PM.

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#3 Stelios


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Posted 01 August 2020 - 01:59 PM

I have an EdgeHD 800 and love it. I use it exclusively with the reducer and an OAG--unless you have a large pixel camera and/or exceptional seeing it will almost never make sense to image at F/10.


I invested in a Moonlite focuser (with controller and motor for autofocus) for the Edge. This lets me lock the mirrors and (in conjunction with OAG) totally eliminates any mirror flop or differential flexure. Well worth the $850 expense for the combo, and I am *not* made of money (still saving for Astrodons). 


Your alternative to the Edge is probably a larger refractor, perhaps an Esprit 120 (which is more-or-less equivalent to my APM115/805). Although the APM is a great scope that improves on what an ED80 can do for medium-sized objects, the Edge beats it on smaller targets such as galaxies and planetaries, even when I pair the APM with the small-pixel ASI183. At comparable image scales the larger aperture is superior. 


The Edge also costs much less, even with the Moonlite thrown in. 

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#4 canyonblue737


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Posted 01 August 2020 - 06:10 PM

Thanks, I really do think it seems the obvious choice for me if I want a significant boost in focal length but without the weight, length etc. that comes with refractors that would approaching the same. Thanks again, glad it sounds sensible... I do want an electronic focuser for it but I am a ASIAir guy and that only works with their own ZWO EAF which unfortunately only works out of the box with a feathertouch focuser on the EdgeHD 8, that would be $315 + $200 for the EAF. There are supposedly some 3D printed parts that might get it to work with the stock focuser so I'll have to look into that as another option if I can get the same results as upgrading to the feathertouch. Thanks again.

#5 jprideaux


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Posted 02 August 2020 - 08:36 AM

I did read elsewhere here on Cloudy Nights that ZWO does have plans to mass-produce and sell their own parts to allow their EAF to be used on the focus knobs of the Edge. I don’t know when this product will be ready.

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