Trying to decide on a larger refractor for imaging galaxies.

Tele Vue NP127is will work great. I use mine for galaxies sometimes, the detail is incredible. Easy to use adapters, spacers, reducers etc. The quality if hard to beat. Check out Jerry Macon’s images for proof. Of course, if I could find one, Ive always wanted an AP 130 !

Jesse Priolo · May 3, 2026, 01:19 PM

Greg, I think I responded to your thread on CN too, but you may run into an issue with a ~130mm scope hitting the tripod legs when imaging near the meridian. I haven’t used a CGX specifically, but I ran into this with my 130mm scopes when imaging with an EQ6-R.

I’ve since moved to iOptron mounts and use the tri-pier, which has eliminated collisions.

I’ll reiterate what I said over on CN too: the AT130EDT is inexpensive but well-made, and there are some terrific images taken with it that you can find just by searching “AT130EDT” in the search bar above.

Thanks Jesse. Sometimes it’s difficult to get a lot of feedback on CN so I posted here too. I have looked at the EDT images on Astrobin. Incredible.

You mentioned you did not want a pier extension but that is the way to make your existing mount work for what you want to do.

I use a pier extension on a skywatcher az-eq6 and not only does it prevent collisions but it will reduce the need to extend the tripod legs all the way so the overall footprint on the ground is smaller and much easier for you to work around, and more stable resulting in marginally better performance.

The 0.63 reducer will make using your C6 much easier and gets you a little more reach than the refractors. I think you can pick these up used for less than $100 on ebay.

[deleted] · May 5, 2026, 12:34 PM

You mentioned you did not want a pier extension but that is the way to make your existing mount work for what you want to do.

I use a pier extension on a skywatcher az-eq6 and not only does it prevent collisions but it will reduce the need to extend the tripod legs all the way so the overall footprint on the ground is smaller and much easier for you to work around, and more stable resulting in marginally better performance.

The 0.63 reducer will make using your C6 much easier and gets you a little more reach than the refractors. I think you can pick these up used for less than $100 on ebay.

Thanks. I have the .63 reducer and I’ve used it for years. There are other issues plaguing me with the C6. (focus shift, back focus, vignetting, balance). As for the pier extension, one is not made for the CGX or any Celestron mount. I did call Astronomics about the Astro-Tech 130EDT, and I contacted Agena Astro about the ASKAR 120mm Apo. Both places told me I would not need a pier extension for these scopes for imaging, if one existed. I’ve got a lot to mull over before purchasing. I appreciate your input.

Greg · May 5, 2026, 01:53 PM

AstroGadac · May 5, 2026, 01:04 PM

I own the Askar 120APO. For larger galaxies it works fine (see for instance https://www.astrobin.com/b6qaon/C/, https://www.astrobin.com/4pkg4g/, https://www.astrobin.com/yio9fc/) but for smaller galaxies its more appropriate for groups/cluster of galaxies otherwise the reach is a bit too limited. However I dont think a 140APO would fare much better, especially since seeing will start limiting things at some point.

In any case for a long refractor like that a pier extension is mandatory. Since I use an harmonic mount whose dec saddles lies low from the RA axis, I had to find one that was 25cm long and I also raised the scope on its dovetail using 2cm riser blocks:

I have 0 risk of crash on the tripod legs now.

Thanks. Oddly, I called Agena Astro yesterday and the person I spoke to uses the ASKAR 120 for imaging without a pier extension. Unfortunately, one is not made for the CGX or any Celestron mount, I’ve been told. The cradle on my mount does sit significantly higher so maybe that will make a difference. One more question….when you say “smaller” galaxies, what size are you thinking of? I’m thinking anything under say 10’ in size is off limits with the 120, and that’s fine. I was looking more in the range of 10’ + Like M63, M64 and larger. With a decent crop could I still get solid images with that scope? Thanks for your input!

A conventional belt and drive mount will have its saddle much higher yes so it could alleviate the need for a pier extension. But I would still check using a low speed maneuver the first time if indeed it clears the tripod legs. You never know.

The galaxy it does well are the big one like M51/M63, probably M64 too so yeah that’s about 10’. Smaller would work too if the framing is interesting with other galaxies around perhaps.

Greg · May 2, 2026, 08:38 PM

easier to use than the C6 and more consistent for galaxies

Looking back at your post it’s not clear to me why you want to stick with refractors for this. I’m also a bit puzzled over what the above line really means. In many ways that C6 is already right focal length range to make galaxies even smaller than 10’ interesting. Have you actually tried it?

Thinking along those same lines why not consider the MK127 Maksutove/Cass? That could be perfect for what you want to do at 1500mm. Another good option would be a 6” RC pulling you out to about 1380mm, fully color correct and no flatteners, reducers or pier extensions needed. Throw an EAF on it and you’re good to go.

AstroGadac · May 5, 2026, 02:01 PM

Greg · May 5, 2026, 01:53 PM

AstroGadac · May 5, 2026, 01:04 PM

I own the Askar 120APO. For larger galaxies it works fine (see for instance https://www.astrobin.com/b6qaon/C/, https://www.astrobin.com/4pkg4g/, https://www.astrobin.com/yio9fc/) but for smaller galaxies its more appropriate for groups/cluster of galaxies otherwise the reach is a bit too limited. However I dont think a 140APO would fare much better, especially since seeing will start limiting things at some point.

In any case for a long refractor like that a pier extension is mandatory. Since I use an harmonic mount whose dec saddles lies low from the RA axis, I had to find one that was 25cm long and I also raised the scope on its dovetail using 2cm riser blocks:

I have 0 risk of crash on the tripod legs now.

Thanks. Oddly, I called Agena Astro yesterday and the person I spoke to uses the ASKAR 120 for imaging without a pier extension. Unfortunately, one is not made for the CGX or any Celestron mount, I’ve been told. The cradle on my mount does sit significantly higher so maybe that will make a difference. One more question….when you say “smaller” galaxies, what size are you thinking of? I’m thinking anything under say 10’ in size is off limits with the 120, and that’s fine. I was looking more in the range of 10’ + Like M63, M64 and larger. With a decent crop could I still get solid images with that scope? Thanks for your input!

A conventional belt and drive mount will have its saddle much higher yes so it could alleviate the need for a pier extension. But I would still check using a low speed maneuver the first time if indeed it clears the tripod legs. You never know.

The galaxy it does well are the big one like M51/M63, probably M64 too so yeah that’s about 10’. Smaller would work too if the framing is interesting with other galaxies around perhaps.

Thanks. I really like the scope and despite it not having super high end glass, I’m not reading about much CA in the scope at all.

I am going to give a response here without reading anything other than your original post. As someone that images a ton of galaxies on widely different imaging systems here is some advice I would give you.

First, do not be as concerned with the size of the visible galaxy on the chip as you may default to doing. For galaxy imaging you care a lot of about resolution and since you have stated you want to use a refractor system for this (good choice) you will not have a diffraction penalty. You do want to use a chip with better ADC than the 533 has. I would recommend the APS-C version of the Sony chipped camera of your choice for this reason.

Next, galaxy imaging is perfected by knowing the field you are working on as best as you can. I would advise people to use the NASA NED database, the WISE database, and the IRSA resources to help you better understand the field prior to imaging it. We at Dark Matters ingest all of this data for our AI we use to program scope operations across our fleet and this data has been priceless for us.

Lastly, don’t get discouraged. This talk of cameras, databases, spectral graphs, etc is very good data, but the most important piece of gear you can ever own in this hobby is the motivation to do it.

I will close, with a scope suggestion though. Celestron Edge C9.25. :) Not what you thought, eh?

For a refractor though, I will offer this: Takahashi TOA150. Lifetime refractor. King of the hill, best corrector, best correction itself. The TOA130 is equally as good.

So in closing - TOA130.

Tony Gondola · May 6, 2026 at 02:33 AM

Another approach is to look at changing your camera rather than the optics. As an example, take your 6” F/4 CarbonStar at 600mm native. Putting a 585 (2.9 micron) on that is equivalent to using the 533 at 774mm. Go even further with a 183 at 2.5 micron pixels and it would be equivalent to shooting the 533 at a focal length of 948mm, exactly where you want to be.

There is definitely merit in putting camera’s with <3.8 micron pixels behind a wide-field scope.

But the reasoning that by making the pixels smaller you see smaller targets, does not tell the whole story. If that would be the case, the best thing to do is just put your iPhone on your scope. The optical design plays a role as well. Horses for courses. So if the target is to go after small-ish galaxies, an optical design with a focal length of >1000mm and aperture as large as budget allows is definitely worth considering.

Take a look at the esprit edx series…(120 or 150 if you can aford) far better optics than the askar

Greg · May 6, 2026, 11:35 AM

Tony Gondola · May 6, 2026, 02:33 AM

Another approach is to look at changing your camera rather than the optics. As an example, take your 6” F/4 CarbonStar at 600mm native. Putting a 585 (2.9 micron) on that is equivalent to using the 533 at 774mm. Go even further with a 183 at 2.5 micron pixels and it would be equivalent to shooting the 533 at a focal length of 948mm, exactly where you want to be.

A very good point. I was actually looking at going the opposite direction, toward a 2600mc for use with my 75mm refractor to be able to capture M31, California neb. and other such very large objects. I hadn’t even considered a smaller sensor than the 533. I appreciate the advice. Not sure I can swing three cameras though. :)

You could actually end up saving money if it meant that you didn’t need to get another OTA.