Celestron 925 standard or 800 edge HD? Which one to buy...

[Evanr]

Hi everyone. This is my first post!

im just about to make my first scope and mount purchase. I’ve done some research and am looking for a high quality viewing scope to get to know everything. My other presrequisite is good portability as I live in Western Australia and dark skies are quite accessible with short car rides. I have young kids too and think they will love it.

‘I’ve been looking at the 8inch edge HD but there are none of them in OZ. This is my pick for what I want. There are quite a few standard 925s around and people have said to me this size and performance will beat the edge HD in quality. I’m aware this is a vague statement. I’m not too versed on my tech speak yet. I do know the edge has corrector technology and a few other elements that the standard doesn’t but I’m questioning if my novice eye would notice.

the 925 is bigger and if I want to experiment with any accessories in the future I’ll be better off getting a bigger mount. This means my portability factor goes down.

is there anyone who has experience who can answer if the small edge HD would outshine the standard 925? Lots speak very highly of the 925.

thanks

Evan

 

 

 

 

 

 

 

[Cosmic Geoff]

I have not used either, but the Edge HD is designed for advanced imaging of small galaxies and the like, where you want correction to the edge of the field.  According to some reports, there may be a quality advantage for visual use (maybe because they undergo a different finishing process), but the full-field correction is not needed for visual use, as the natural reaction of a visual observer viewing planets or double stars will be to centre them in the field.

As you say, the C9.25 also has a good reputation.

The standard C8 OTA is highly portable in itself, but something to watch out for is how you break down whatever OTA and mount you choose for transit.  The C8 is normally kept attached to its single-arm mount head and because of its bulk it can be awkward to take it off the mount for transit and re-fit. And the orange tube C8 SE variant does not have a tube handle!

The C9.25 will be a step heavier and bulkier, and less easy to handle, but if you figure out how to get it on and off its mount without dropping it, you should be okay. If there is no handy handle, you can buy an accessory bar and fix it to the tube opposite the dovetail bar. 

If car rides are planned, do NOT buy the CPC925 variant - that would be a great scope but its OTA/mount assembly (non-separable) is very heavy.

 

[Starflyer]

What do you plan to mount it on and are you looking to do DSO imaging through it?  Both scopes will be challenging to image through and unless you have a serious mount it'll be frustrating.

Both are big scopes and the long focal length will mean something like an NEQ6 Pro upwards for imaging, even with the focal reducer.

The standard 9.25 doesn't have mirror lock so be prepared to budget for an OAG and sensitive guide camera.

[Evanr]

Thanks @Cosmic Geoff

yeh I think that’s it. If I wanted to do photography the edge is a better long term choice. 
good points on tube loading. 
‘I was looking at the 120 SW originally. Big jump from $900 to the EDs.

‘I’ll see what the stock situation on Monday is. Thanks for equip advice.

‘Evan

[Evanr]

Thanks @Starflyer

i was looking at the CGX mount for the 925. The neq6 is nice. The guys at the shop recommended the eq6. $$ though

 

[Cosmic Geoff]

18 minutes ago, Evanr said:

i was looking at the CGX mount for the 925. The neq6 is nice. The guys at the shop recommended the eq6. $$ though

Depends what you want to do with it.  If it's purely for visual, one of the Celestron alt-az packages would be far easier to use.  You don't want an equatorial unless you intend to do imaging; if you don't image, the extra complication of the equatorial with polar alignment, counterweights etc is just a drag on your time.  Unless you intend to image, a CGX or NEQ6 is, I think, more mount than you need.  These larger mounts are heavy. And if you do intend to image, you should start with a small short focal length refractor, not a long fl SCT

In short, I suggest you get a package with an alt-az Goto mount, and if you want to image, go shopping again for entirely different kit. I have used both the Nexstar alt-az system and a Synscan equatorial Goto, and I would not recommend the latter to anyone unless there was no alternative. I have had the Synscan for a year and not got on with it at all.

[nfotis]

I got a used C9.25 XLT from a forum member (my other is a Skymax 127). I feel that's about the limit of portability (I can carry it in an IKEA shoulder bag)

For planetary observation and imaging, it's a very good match. If you have a camera up to 4/3rds or so (or maybe stretch to APS-C), you shouldn't have much problem with the image quality (depends on the particular specimen, of course, and the variety of quality). This particular model is a bit flatter than others, because the primary mirror is slower than a regular SCT from Celestron.

Ed Ting has a nice comparison of the C9.25 with other SCTs:

 

The Edge HD additional cost is acceptable if you are planning to do imaging of DSO objects and plan to use the whole image circle with a large sensor. Planetary imaging uses only the center of the circle, so no problem (it seems that the Edge HD are more consistently good, but I don't have numbers to prove it).

If you are planning to use Hyperstar for imaging, the C9.25 might be better than the C8, if you can manhandle alone the package. A HEQ5 mount is enough for visual with the C9.25, and near the limits for long exposures with this OTA, from what I understand.

N.F.

 

[Evanr]

Thanks @nfotis 

im starting to think I need 2 telescopes! That video review is great and has almost settled my mind on not getting the 925 as I need a bit more portability. As you say I need to assess what I want to do with it. With me being an amateur photographer the appetite for AP I know will come eventually but I have young kids and I know that sucks a lot of time late at night. I’m sure when I have more time it will be easier to manage. I guess that’s reason I was looking at the 8 edge as it was high quality but wasn’t a refractor. Plus I just like them. 
 

I really like the look of the Williams optics refractors or the redcats or the larger SW Esprits. That’s a $10k AUD exercise though. This seems like a sweet setup. Ive watched a few vids and read a lot to get my knowledge up but the majority of online chatter is to do with AP. 

[Evanr]

https://www.space.com/amp/astrophotographer-12-years-mosaic-image-milky-way-galaxy
 

 

[CraigT82]

1 hour ago, Evanr said:

With me being an amateur photographer the appetite for AP I know will come eventually but I have young kids and I know that sucks a lot of time late at night.

It doesn't have to!

Im just starting out in DSO photography and my kit is automated enough for me to be indoors whilst it does its thing, I even go to bed and leave it running. I don't have an observatory I just have it set up on my rear patio. I set an alarm for when the imaging sequence ends at 4am or whatever and then I go down and switch the power off  and throw a cover over it before going back to bed. 

I started out with visual observing, then moved into planetary and lunar imaging and now into have moved into DSO imaging, and out of all that it's the DSO imaging involves the least time at the scope. However be warned that it is also the most expensive aspect of this hobby that I've encountered so far!

Edited March 21, 2021 by CraigT82

[Cosmic Geoff]

12 hours ago, Evanr said:

I'm starting to think I need 2 telescopes!

Right. I am sure you will in the end be happier getting two outfits, rather than pursuing the unattainable dream of one rig fits everything.

I suspect that the novelty of lugging a heavy CGX or EQ-6 mount out to the wilds and setting it up for family visual viewing will wear off quickly. 

Before you commit to using a 8" Edge HD with a focal reducer for imaging, check out the price of that scope's focal reducer. Even here it is eye-wateringly expensive, and I don't know much about these things but you could probably buy a decent imaging refractor for that money,

I never took a deep-space image with my C8 or CPC800 that was any encouragement to go further, but I have taken a lot of pleasing images with a planetary camera on a cheap 102mm f5 achro refractor mounted on an equally cheapo SLT mount head, and managed to do things like identifying the minor planet Pluto and imaging things I could not see from here with any of my other telescopes.  So I am not recommending that you start deep-space imaging with a 8" SCT.

[nfotis]

Everyone suggests to start DSO imaging with an 80ED or similar refractor scope.

Diving directly into DSO imaging with an SCT is usually the hardest way to do it.

N.F

[philtodd]

On 20/03/2021 at 18:18, nfotis said:

I got a used C9.25 XLT from a forum member (my other is a Skymax 127). I feel that's about the limit of portability (I can carry it in an IKEA shoulder bag)

For planetary observation and imaging, it's a very good match. If you have a camera up to 4/3rds or so (or maybe stretch to APS-C), you shouldn't have much problem with the image quality (depends on the particular specimen, of course, and the variety of quality). This particular model is a bit flatter than others, because the primary mirror is slower than a regular SCT from Celestron.

Ed Ting has a nice comparison of the C9.25 with other SCTs:

 

The Edge HD additional cost is acceptable if you are planning to do imaging of DSO objects and plan to use the whole image circle with a large sensor. Planetary imaging uses only the center of the circle, so no problem (it seems that the Edge HD are more consistently good, but I don't have numbers to prove it).

If you are planning to use Hyperstar for imaging, the C9.25 might be better than the C8, if you can manhandle alone the package. A HEQ5 mount is enough for visual with the C9.25, and near the limits for long exposures with this OTA, from what I understand.

N.F.

 

That Ed Ting video is really useful showing the telescopes side by side.

[scotty38]

I'm a beginner too and had never looked through a scope a couple of months ago but dived in head first and bought an imaging setup based around a WO GT81. I had a couple of beginners luck nights and managed an image or two (my M42 is on here somewhere) but since then have had nothing but issues on the few clear nights I've had....

It's massively fascinating and frustrating at the same time and there seems nothing worse than the catch-22 of spending clear nights setting up kit rather than taking pictures. I am glad I made it as easy as possible with a short refractor as there's enough to learn or go wrong as it is 👍

[newbie alert]

It really depends on what you want to do with it.. the edge I'd has the upper hand for imaging as it has a flatter field, and depends on what type of imaging, for planetary the 9.25 would be better, for deep sky I wouldn't suggest either..deepsky imaging with that sort of focal length isn't easy, far easier with a widefield frac... and living where you do most of us northern hemisphere folk would kill to have your targets on offer combined with dark skies!!

Mounts, that's another subject you need to address.. 

[garryblueboy]

I’ve owned both HD edge  8 ,11, 14 scopes and regular C8 C9.25 C11 and visually the edge are better 

[Evanr]

Thank you all. I must admit I’m impressed with the sharing of knowledge in this hobby already. In the time I wrote my first thread I have actually purchased the edge HD and there was a special on the SW 120/600 frac as the basic kit so i have bought them both for different reasons. The AZ3 mount seems a bit rough around the edges but it’ll do to start me. The biggest learning I have found is that I need to respect the equipment for different reasons and there is a certain level of patience and knowledge I’m happy to commit to. I’m excited!

Im off to Coral Bay next week which is a coastal location about 14 hours drive north of Perth in Western Australia. Last time I was up there was pre COVID and I remember thinking about getting a telescope to view the night sky so this will be a good moment. The dark skies are so amazing in this part of the world you almost don’t need a telescope you just lay on the ground and look up. It is insane. Obviously I have one now so I’m looking forward to a bit of viewing practise.

Thanks everyone for your advice. I will post a non telescoped picture of the sky with my standard DSLR for you all.

Later

Evan

 

[nfotis]

Best of luck with your purchases (I suppose that the delivery won't be very late?)

The mount is usually the limiting part, for astrophotographers the HEQ5 mount is usually the minimum (albeit a bit agrarian). But all these items will need enough time to exercise and be good with handling.

N.F.

 

[tonylumley]

scotty38, for cloudy skys you can blame me, been bad since my new mount arrived, seems if its clear I haven't set up and if its cloudy Im itching to get out and someone(her indoors)  needs someone to run about, ooh well ..............................................................................