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C8 vs C11 / Edge HD or No?

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#1 Brandon E

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Posted 25 October 2021 - 07:46 AM

For many years, I have been using a non-computerized 8" dobs and am very happy with it. I recently moved to a bortle 6 area and I'm finding it pretty difficult to locate objects by star hopping. I have been wanting to get a computerized go-to setup for years now and decided to take the plunge.

I want a EAA rig with a focus on live viewing and NOT photography (today). I have a budget of $4500 and looking to maximize my investment.


First, HD optics for EAA, good? Bad? Not relevant? I ask because I had seen several comments on the 8 EVO EDGE HD being not as good as the Non-HD version for EAA. My understanding is HD optics are going to mostly benefit photography/imaging - https://www.celestro...s/edgehd-optics - so I am not really clear why you would not want this for EAA?


For the best telescope/mount for visual and EAA that allows me the flexibility to later branch, I think C11 on CGX makes most sense. It will be a great setup for visual or EAA. It will max my budget but I can add StarSense, WiFi, camera etc later.

I also get an EQ mount and if astrophotography becomes a later interest, I have options. I could add HyperStar to the C11 or go with the traditional camera at the back. I could even get a different OTA all together and do AP with that.


Basically, I am looking for a sanity check on my choice of opting for non-EdgeHD and the C11 over an 8" Edge HD on CGX.

Edited by Brandon E, 25 October 2021 - 08:37 AM.


#2 Tfer

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Posted 25 October 2021 - 09:10 AM

I love my C11, but the extra aperture isn’t required for EAA.  In fact, the longer focal length can actually be a bit of a hindrance.  I got it because of my interest in planetary imaging, and in that specific case, the greater resolution is a huge advantage.

 

For EAA in either case, you’ll require a reducer; either the 6.3 (for the standard version) or the 0.7 (for the Edge), so that needs to be budgeted in.

 

If you suspect that you’ll be moving towards AP, I’d probably go for the 8” Edge on an EQ mount.  Wider FOV and corrected optics would be more important than the resolution advantage of the standard 11”.


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#3 Mark Lovik

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Posted 25 October 2021 - 09:12 AM

Many of the recommendations depend on what you want to do with EAA.  I only have experience with the 8" non-Edge version of an SCT (very old Meade) and just getting good views with it.  I started with a much smaller scope first (AT72EDii with reducer).

 

Getting a larger mount is a good choice as long as the size and weight do not cause problems.  It is better to over mount than undermount - even for EAA.  EAA is more forgiving, but the more you push the limits, the more hassle you will incur.  A bigger mount with good polar alignment also makes it easier to get good results without guiding (depend on the mount and short subs here).

 

I chose to start EAA with the refractor first and glad it was my initial direction.  My little refractor with an inexpensive mono-camera (ASI 178) to start was an easy way to get into EAA and with surprising results.  I could see (with EAA) Magnitude 17 galaxies in a Bortle 5 sky within 2-5 minutes.  I scaled to the SCT in the end by:

 

1. Start small and mono-only (inexpensive and get experience to scale up the hardware)

2. Added color later (much slower imaging than mono and added complexity getting a decent color balance)

3. Scaled up to the SCT (using reducers to match the scope -- not a clean purchased implementation).  Using reducers is recommended for most camera sensor sizes.

 

Going stepwise made each jump easier for success.  You may want to consider starting with a mount and small refractor in your budget.  By the time you scale to the SCT you will have most of the answers that fit your intents. 

 

You also have the option to dual mount a smaller refractor on the SCT at the end, and select the scope for the object being viewed.


Edited by Mark Lovik, 25 October 2021 - 09:21 AM.


#4 GoFish

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Posted 25 October 2021 - 09:23 AM

For EAA, I’d go with 8” at f/6.3 (non-Edge), EQ mount, and ASIAir. Plate solving takes away the need for StarSense (and aligning in general, actually).
 

Mount-wise, I’d opt for an upgrade from the AVX. I have an AVX, and I use it in the exact configuration I’m suggesting here. But I don’t believe it tracks as well as either of my SW mounts (NEQ6/Atlas or HEQ5/Sirius). And I really prefer an eqdirect cable vs a handset+cable.

 

Eventually you might upgrade to HyperStar, as even 1260mm is a bit long for EAA. 


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#5 GazingOli

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Posted 25 October 2021 - 10:05 AM

The choice of the scope depends definitely on what you want to do with it, but one thing you may want to consider is also the weight of the tube. The 11" is a lot more difficult to handle than an 8". Then the Edge-HD is more expensive, not only the tube alone but all the acessories as well.

 

For EAA only I am doing very well with an Evolution 8 on wedge. This is very easy to handle and good enough for EAA live stacking with exposures up to 60 s. The advantage is also that I do not have to care about Meridian flip and can go criss-cross the night skies. As soon as you seriously consider real AP, then you better get a GEM mount.

 

CS.Oli


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#6 Brandon E

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Posted 25 October 2021 - 10:20 AM

Thanks for the responses!

What are my viewing goals?

Today - Visual /EAA
Future - Maybe AP. Maybe Not? I want flexibility here.

#7 Brandon E

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Posted 25 October 2021 - 10:39 AM

Is the CGX capable to handle C8 or 9.25”? I think the CGX-L is required for the C11 and makes it too pricey.

Maybe C8 or C9 EdgeHD on CGX is the versatility I’m looking for?

#8 GazingOli

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Posted 25 October 2021 - 10:44 AM

Do you have a backyard observatory? Then go for the 11".

 

If not, your back will thank you to rather use the 8" or the 9.25". The latter has a bigger baffle diameter which makes it more suitable for bigger camera sensors, like the ASI 294 (I hate the vignetting of the C8 @f/6.3 with the ASI294).

 

For AP use a GEM with at least 2x the load capacity of the weight of your scope, the mount is even more important than the scope. You will want to add more components like guiding or maybe even a piggy-pack scope for wide field AP.

 

CS.Oli


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#9 steveincolo

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Posted 25 October 2021 - 10:46 AM

Is the CGX capable to handle C8 or 9.25”? I think the CGX-L is required for the C11 and makes it too pricey.

Maybe C8 or C9 EdgeHD on CGX is the versatility I’m looking for?

I don't know why, but the C9.25 and C9.25 Edge are quite a bit heavier than their C8 counterparts (20/12.5 and 21/14, respectively).  More than I'd expect if weight were proportional to the square of the aperture.  (I'd use the cube of the aperture if they were solids, but they're just tubes.)



#10 Brandon E

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Posted 25 October 2021 - 10:59 AM

Do you have a backyard observatory? Then go for the 11".

If not, your back will thank you to rather use the 8" or the 9.25". The latter has a bigger baffle diameter which makes it more suitable for bigger camera sensors, like the ASI 294 (I hate the vignetting of the C8 @f/6.3 with the ASI294).

For AP use a GEM with at least 2x the load capacity of the weight of your scope, the mount is even more important than the scope. You will want to add more components like guiding or maybe even a piggy-pack scope for wide field AP.

CS.Oli


Thanks. No observatory.

CGX with 8 HD and 9.25 non hd is at $3500 leaving room for a camera and FR. How is the vignetting with the 8 HD? Same as 8?

9.25 HD on CGX caps my budget.

Edited by Brandon E, 25 October 2021 - 11:14 AM.


#11 Brandon E

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Posted 25 October 2021 - 11:01 AM

I don't know why, but the C9.25 and C9.25 Edge are quite a bit heavier than their C8 counterparts (20/12.5 and 21/14, respectively). More than I'd expect if weight were proportional to the square of the aperture. (I'd use the cube of the aperture if they were solids, but they're just tubes.)


CGX is rated at 55lbs so should be able to handle both, right?

#12 steveincolo

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Posted 25 October 2021 - 11:08 AM

CGX is rated at 55lbs so should be able to handle both, right?

I'd double check over in the Mounts forum.


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#13 Tfer

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Posted 25 October 2021 - 11:19 AM

Thanks for the responses!

What are my viewing goals?

Today - Visual /EAA
Future - Maybe AP. Maybe Not? I want flexibility here.

Corrected optics should be mandatory for your goals, as well as a GEM.  No planet Imaging?  Get either the 8” or 9.25” Edge (although the 9.25 is also a VERY solid planetary option).

 

BTW, once you crack the EAA code, your scope will never see another eyepiece. 
 

With the 9.25, the 0.7 reducer, a GEM, a widefield camera along with an inexpensive planetary camera, you are future proofed. 


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#14 GazingOli

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Posted 25 October 2021 - 11:30 AM

How is the vignetting with the 8 HD? Same as 8?

same baffle diameter - same vignetting. however you can work around with flats (as I do)

 

CS.Oli


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#15 alphatripleplus

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Posted 25 October 2021 - 11:57 AM

CGX is rated at 55lbs so should be able to handle both, right?

Yes, but you mention you may be interested in AP down the road. If that is  the case, you might want to consider a better mount as the demands on a mount for long exposure AP are more severe than for EAA; Celestron typically rate their mount capacity for visual rather than AP usage. For EAA, you should be fine with the CGX with the larger scopes you mention. 


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#16 Brandon E

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Posted 25 October 2021 - 12:14 PM

Corrected optics should be mandatory for your goals, as well as a GEM.  No planet Imaging?  Get either the 8” or 9.25” Edge (although the 9.25 is also a VERY solid planetary option).

 

BTW, once you crack the EAA code, your scope will never see another eyepiece. 
 

With the 9.25, the 0.7 reducer, a GEM, a widefield camera along with an inexpensive planetary camera, you are future proofed. 

This is what I was thinking or hoping to hear. To be clear you are suggesting Edge HD for either 8" or 9.25"?

Does Edge HD provide any benefits for visual or EAA? For AP, sure but I think if I were to get into AP, I would probably buy an APO and use it with the CGX and keep the C8/9.25 for Visual/EAA. Also the price point for 9.25 Edge caps my budget.

If I go with the C9.25 Edge + CGX, I have no budget left for camera or FR and would need to get later on.
If I go with the C9.25 NON-Edge + CGX, I can get a camera and FR when I order it.
 

 

Yes, but you mention you may be interested in AP down the road. If that is  the case, you might want to consider a better mount as the demands on a mount for long exposure AP are more severe than for EAA; Celestron typically rate their mount capacity for visual rather than AP usage. For EAA, you should be fine with the CGX with the larger scopes you mention. 

Not sure I understand. The CGX is not a capable mount for AP? That infers the only Celestron mount suitable for longer exposure AP is the GSX-L? That cannot be true? 

Also, I'm not sure I would use the C8 or C9.25 for AP and I would likely use an APO. Either way, there is a HUGE IF here with AP. I mostly want to have a great visual and EAA setup with the flexibility to use the mount later for AP should I catch that bug. grin.gif


Edited by Brandon E, 25 October 2021 - 12:29 PM.


#17 Tfer

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Posted 25 October 2021 - 12:24 PM

This is what I was thinking or hoping to hear. To be clear you are suggesting Edge HD for either 8" or 9.25"?

If AP is a possibility, the spherical aberrations at the edge of the standard SCT FOV will drive you crazy.  Even in EAA, when I zoom into 100%, the stars towards the outside are all banana shaped. 
 

Because my interest lies in the object that I’m viewing, the outside is far less relevant to me.  
 

Cropping those stars out further reduces your FOV, so if AP has a chance to become an interest, save yourself the grief down the road, and go with the Edge version. 
 

If you’re convinced that planetary imaging holds no interest for you, skip the 9.25 and get the 8” Edge. Use the savings on your camera. 


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#18 Brandon E

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Posted 25 October 2021 - 12:33 PM

If AP is a possibility, the spherical aberrations at the edge of the standard SCT FOV will drive you crazy.  Even in EAA, when I zoom into 100%, the stars towards the outside are all banana shaped. 
 

Because my interest lies in the object that I’m viewing, the outside is far less relevant to me.  
 

Cropping those stars out further reduces your FOV, so if AP has a chance to become an interest, save yourself the grief down the road, and go with the Edge version. 
 

If you’re convinced that planetary imaging holds no interest for you, skip the 9.25 and get the 8” Edge. Use the savings on your camera. 

Thanks! Planetary viewing and EAA for sure. 1h exposure imaging of Jupiter, not today but someday, maybe.
 

That said, I think I will go with the 9.25 Edge + CGX because this gives the most flexibility. I can wait on the camera for a few months and get to know the scope and just enjoy visual observing.


Appreciate all the help!


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#19 alphatripleplus

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Posted 25 October 2021 - 01:18 PM

 

Not sure I understand. The CGX is not a capable mount for AP? That infers the only Celestron mount suitable for longer exposure AP is the GSX-L? That cannot be true? 

 

The capability of the CGX (or the CGX-L) for AP versus other mounts is something often discussed in the Mounts forum, which would give you some opinions on the topic. As I mentioned, for EAA it will be fine. 


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#20 cnbilbo

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Posted 25 October 2021 - 01:42 PM

For many years, I have been using a non-computerized 8" dobs and am very happy with it. I recently moved to a bortle 6 area and I'm finding it pretty difficult to locate objects by star hopping. I have been wanting to get a computerized go-to setup for years now and decided to take the plunge.

I want a EAA rig with a focus on live viewing and NOT photography (today). I have a budget of $4500 and looking to maximize my investment.

Hi Brandon

 

You sound like a man after my own heart. If you take a look my signature (at the bottom) You'll see I have most of the kit you mention.

Having had a Dob for years you will most likely find eq mounts to be very annoying at the least.

 

My solution was in two setups, One for "serious" use when I know the skies are going to be kind and I have time to spare. The other when I'm pushed or weather is erratic.

 

1: A CPC 1100 HD, fork mounted scope with a small refractor (megrez 72) mounted on the top for widefield views. The CPC is fairly easy to handle and can be set up in a reasonable amount of time.

 

2: Celestron evolution mount with Meade 8" ACF. This is lightweight, Very portable, battery powered (Internal) and can be setup in minutes, Its also used for solar Halpha (Lunt LS60) and white light (megrez 72) as the mount has the standard vixen clamp. This is my most used kit.

 

Edge HD optics are as you say primarily for photography with (the dedicated 0.7x reducer), A waste of money If you were thinking of using a Hyperstar for f/2 as it uses only the main mirror. Buy a standard SCT and use the money you save to buy the Hyperstar & maybe a wedge or other goodies.

 

Steve


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#21 Brandon E

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Posted 25 October 2021 - 02:45 PM

The capability of the CGX (or the CGX-L) for AP versus other mounts is something often discussed in the Mounts forum, which would give you some opinions on the topic. As I mentioned, for EAA it will be fine. 

Thanks! Makes sense!

 

 

 

Hi Brandon

 

You sound like a man after my own heart. If you take a look my signature (at the bottom) You'll see I have most of the kit you mention.

Having had a Dob for years you will most likely find eq mounts to be very annoying at the least.

 

My solution was in two setups, One for "serious" use when I know the skies are going to be kind and I have time to spare. The other when I'm pushed or weather is erratic.

 

1: A CPC 1100 HD, fork mounted scope with a small refractor (megrez 72) mounted on the top for widefield views. The CPC is fairly easy to handle and can be set up in a reasonable amount of time.

 

2: Celestron evolution mount with Meade 8" ACF. This is lightweight, Very portable, battery powered (Internal) and can be setup in minutes, Its also used for solar Halpha (Lunt LS60) and white light (megrez 72) as the mount has the standard vixen clamp. This is my most used kit.

 

Edge HD optics are as you say primarily for photography with (the dedicated 0.7x reducer), A waste of money If you were thinking of using a Hyperstar for f/2 as it uses only the main mirror. Buy a standard SCT and use the money you save to buy the Hyperstar & maybe a wedge or other goodies.

 

Steve

Thanks, Steve!

This is where my head was with the Edge HD stuff. This rig would be my viewing/EAA setup and if I want to do imaging, I can use HyperStar, as you mentioned, or PrtScn while live viewing for that matter. Image quality is not important to me here.

IF I decide to delve into AP, I have an EQ mount. By not going with the Evolution mount, I avoid the clearance issues using a FR etc. 

Here is where I am at, as of now and leaning towards the non-Edge C9.25 because this setup is mainly for viewing/EAA. However, I know I will be happy with either setup for viewing/EAA.

C9.25 + CGX (non-Edge) allows room to buy camera, focal reducer, maybe StarSense and WiFi too.
C9.25 + CGX (EDGE HD) taps my budget and would need to wait on EAA accessories. 


Edited by Brandon E, 25 October 2021 - 02:51 PM.


#22 GoFish

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Posted 25 October 2021 - 03:44 PM

Perhaps you’ve considered this already and decided that planetary photos/views outweighs:  the 9.25 will give you marginally smaller FOV than the 8. This will come into play on larger EAA objects, like M42. 
 

Plus, even a C8 at f/6.3 will oversample with popular EAA cameras that have 4.5-ish micron pixels. The 9.25 will oversample even more. So you don’t get any EAA return on the FOV you give up. 
 

There is no one perfect solution!  You just pick the one that comes the closest and go with it. I think the 9.25 is a fine choice, but just be aware that it comes at a small cost to FOV.


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#23 Clouzot

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Posted 25 October 2021 - 04:11 PM


IF I decide to delve into AP, I have an EQ mount. By not going with the Evolution mount, I avoid the clearance issues using a FR etc. 

Here is where I am at, as of now and leaning towards the non-Edge C9.25 because this setup is mainly for viewing/EAA. However, I know I will be happy with either setup for viewing/EAA.

C9.25 + CGX (non-Edge) allows room to buy camera, focal reducer, maybe StarSense and WiFi too.
C9.25 + CGX (EDGE HD) taps my budget and would need to wait on EAA accessories. 

I've been using a standard XLT C9.25 for years. It was originally on an Evo mount, to which I added a wedge, then switched to an AVX (which is a bit too light for such an OTA), mainly for portability reasons.

Then I sold everything and got my current portable EQ mount.

 

Generally speaking, for any kind of imaging venture, the focal ratio and the tracking are the most important things to consider, not the size. So don't go cheap on the mount, but get the smaller OTA you are comfortable with. I know, size matters and imho the C9 is the sweet spot if you want size and resolution (the C11 is really a large, heavy beast and the EdgeHD version even more so). But depending on your local conditions, a C8 will probably deliver similar performance with a lower budget, and will be easier on your back.

 

Speaking of heavy beasts: the CGX is not really what I would call transportable. Provided the chosen OTA is not too large, with a non-permanent setup you may perhaps want to look into lighter and less expensive options (CGEM II), maybe even into other brands (iOptron CEM40, GEM45...).

 

Starsense: I had one. It was nice to have with an alt-az mount in 2017-2018, but thanks to advances in platesolving you can now forget about it. Get a small guidescope and a guide camera, and (polar-, goto-) align your mount via platesolving (ASIAir or Sharpcap or NINA).

 

EdgeHD / non-Edge: the latter is perfectly OK for EAA, and even for AP (granted, the EdgeHD is better at imaging with its almost flat field, and EAA is imaging; but you'll certainly use a focal reducer and that also compensates for curvature to some degree). Get an XLT and use the budget difference to buy a nice camera.

 

Camera: don't go too large at first (tilt, vignetting). The ASI533MC is a nice, clean camera for color EAA. A bit more expensive, and well suited to SCTs: the ASI294MC.

 

My suggestion: C8-XLT on CGEM II or a similar mount ($2500-3000 total), x0.63 reducer (Celestron, $150), guidescope (50-60mm, $275-$300), guide camera ($300), ASIAir Pro ($300), main camera ASI533 ($900). Total: $4100-4600 new, so around your budget, and you'll be good to go.

 

The first add-on would be a motor focuser, the ZWO EAF is not the best one but it works and is compatible with the ASIAir. And you can always upgrade this or that element later should you feel an irrepressible draw for nitpicking serious astrophotography (Starizona reducer, larger camera, filters and filter wheel, EdgeHD OTA, Hyperstar...).
 


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#24 Brandon E

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Posted 25 October 2021 - 05:38 PM

I've been using a standard XLT C9.25 for years. It was originally on an Evo mount, to which I added a wedge, then switched to an AVX (which is a bit too light for such an OTA), mainly for portability reasons.

Then I sold everything and got my current portable EQ mount.

 

Generally speaking, for any kind of imaging venture, the focal ratio and the tracking are the most important things to consider, not the size. So don't go cheap on the mount, but get the smaller OTA you are comfortable with. I know, size matters and imho the C9 is the sweet spot if you want size and resolution (the C11 is really a large, heavy beast and the EdgeHD version even more so). But depending on your local conditions, a C8 will probably deliver similar performance with a lower budget, and will be easier on your back.

 

Speaking of heavy beasts: the CGX is not really what I would call transportable. Provided the chosen OTA is not too large, with a non-permanent setup you may perhaps want to look into lighter and less expensive options (CGEM II), maybe even into other brands (iOptron CEM40, GEM45...).

 

Starsense: I had one. It was nice to have with an alt-az mount in 2017-2018, but thanks to advances in platesolving you can now forget about it. Get a small guidescope and a guide camera, and (polar-, goto-) align your mount via platesolving (ASIAir or Sharpcap or NINA).

 

EdgeHD / non-Edge: the latter is perfectly OK for EAA, and even for AP (granted, the EdgeHD is better at imaging with its almost flat field, and EAA is imaging; but you'll certainly use a focal reducer and that also compensates for curvature to some degree). Get an XLT and use the budget difference to buy a nice camera.

 

Camera: don't go too large at first (tilt, vignetting). The ASI533MC is a nice, clean camera for color EAA. A bit more expensive, and well suited to SCTs: the ASI294MC.

 

My suggestion: C8-XLT on CGEM II or a similar mount ($2500-3000 total), x0.63 reducer (Celestron, $150), guidescope (50-60mm, $275-$300), guide camera ($300), ASIAir Pro ($300), main camera ASI533 ($900). Total: $4100-4600 new, so around your budget, and you'll be good to go.

 

The first add-on would be a motor focuser, the ZWO EAF is not the best one but it works and is compatible with the ASIAir. And you can always upgrade this or that element later should you feel an irrepressible draw for nitpicking serious astrophotography (Starizona reducer, larger camera, filters and filter wheel, EdgeHD OTA, Hyperstar...).
 

I will mostly be observing in my backyard. Bortle 6 ish. Not sure how that impacts going with an 8 vs 9.25. I think EDGE will stretch my budget with minimal gains, to be honest so agree there.

I was leaning towards the CGX to help reduce future costs on an EQ mount. It's not often I get the green light to spend 4k + on a hobby so trying to get the big stuff covered so to last me the longest. If the CGEM II will handle the 8" OTA and not losing out on any features in the CGX, I'm all for saving the money.

I started with the EVO 8 however, got concerned with EVO mount and spacing issues at the back. Plus I want an EQ should I want to go do some AP later with a different OTA. However, I am not familiar with guidescope/plate solving. StarSense was a feature I was leaning on because I'm in a bortle 6 area and I have a very obstructed view N, and NE and polar alignment may be difficult. I will need to look into plate solving further to learn more about that.

 

How is a guidescope + camera + ?? (~ $600) better than StarSense at $399 if they accomplish the same thing? 

Also, "guide camera ($300)" -- Which guide camera do you suggest?

 

I planned to get ASI294MC non-cooled version around $699 I think. I also planned to get a motor focuser so I could sit in the house and fully control the scope.

 

Moving away from the simplicity of a non-computerized dobs to all of this is frankly fun and exciting. I'm not sure why I've not looked into EAA before. Being a developer by trade, it seems logic I would have dove head first into EAA... Ha!


Edited by Brandon E, 25 October 2021 - 07:18 PM.


#25 Clouzot

Clouzot

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Posted 26 October 2021 - 02:43 AM

I will mostly be observing in my backyard. Bortle 6 ish. Not sure how that impacts going with an 8 vs 9.25. I think EDGE will stretch my budget with minimal gains, to be honest so agree there.

I was leaning towards the CGX to help reduce future costs on an EQ mount. It's not often I get the green light to spend 4k + on a hobby so trying to get the big stuff covered so to last me the longest. If the CGEM II will handle the 8" OTA and not losing out on any features in the CGX, I'm all for saving the money.

A CGEM II will definitely handle a 8" OTA, but you'd lose a couple things:
- direct USB connection to the mount (with the CGEM it passes through the handcontrol's USB port instead)
- payload capacity (40 lbs VS 55 lbs)

The way you use it is quite similar, all Celestron EQ mounts share a common handcontrol, CPWI is compatible with all of them, both the CGEM and CGX have PPEC, and with a 8" OTA the tracking performance should be quite similar.

However, going with the CGX is totally respectable. It's a nice mount (but, again, a bit on the heavy side)... and an oversized mount never hurts (save your back and budget).

 

I started with the EVO 8 however, got concerned with EVO mount and spacing issues at the back. Plus I want an EQ should I want to go do some AP later with a different OTA. However, I am not familiar with guidescope/plate solving. StarSense was a feature I was leaning on because I'm in a bortle 6 area and I have a very obstructed view N, and NE and polar alignment may be difficult. I will need to look into plate solving further to learn more about that.
 
How is a guidescope + camera + ?? (~ $600) better than StarSense at $399 if they accomplish the same thing? 
Also, "guide camera ($300)" -- Which guide camera do you suggest?

They accomplish the same thing, but Starsense is really limited in what it can achieve:

- it can't guide. By experience, once it's set up, autoguiding is really nice to have, even for EAA as you will certainly use long exposures at some point (almost everyone does: filters, faint objects, you name it)

- it won't do polar alignment (but as you have a limited sky view, that argument is maybe moot)

- it won't recenter your mount after a goto.

 

You can see Starsense as a nice helper tool for visual observers: it will align your mount with no additional electronics. But as you're considering EAA, which means having at least some kind of a mount-side computer (be it an ASIAir Pro/Plus or a fully featured PC), there are other software tools available that will make your life even more easier. NINA has a 3-star polar alignment routine that works really, really well when you have no view on Polaris. Sharpcap and ASIAir have a fast and reliable polar alignment feature.

 

As for the guide camera: a mono 290mini is the usual choice, while it lasts (Sony is retiring the sensor I'm told).

 

I planned to get ASI294MC non-cooled version around $699 I think. I also planned to get a motor focuser so I could sit in the house and fully control the scope.

 

That might be where I differ the most: really, get a cooled camera if possible.

 

I'm not saying one cannot do EAA with a non-cooled camera (I did for 2 years and I was happy with that), but the comfort you get with a cooled version is invaluable, all the more as the 294, while nice and sensitive and a perfect match to the long focal lengths of SCTs, has a lot of thermal noise. Believe me, you'll find yourself trying to capture 15s+ exposures in no time, and that's where a cooled version will shine.

 

I know, it's a tricky decision: there's always a better option, but you only have so much budget (and opportunity to spend it). Granted, all elements are important, but if I had to prioritize things for EAA, the camera would be first, followed by the mount, and the OTA would be last.


Edited by Clouzot, 26 October 2021 - 08:56 AM.

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