Refractor suggestion

Topic starter

Feb 28, 2022

Hi everyone!

I am looking for suggestions for my refractor. This refractor will be on EQ6-R mount.
I'll be using the ASI294MM and Astrodon filters on it.

I love to see round tight stars on my images (which I am struggling).
I am looking to image galaxies mostly and some DSO's with this scope. I am looking to keep this scope for at least a couple of years before upgrading to premium scopes.

Constraints -
1. Cost is a limiting factor. So I am ruling out the premium refractors. (including Esprit 120 and William Optics FLT132)
2. Trying to avoid doublets.
3. I live in the united states, so I'll be limited to brands that are available here. Imports in a hassle.
4. Ruling out ES 127 ED/FCD100 option, because I don't like their focusers.

Based on my research I have narrowed it down to AT130, TS130, AT115.

Here are my questions -
1. AT115EDT or AT130EDT for better stars and color correction?

2. TS optics 130 photoline would have been my choice if it was available in USA without the need for import and shipping.
Has anyone compared them in the past? Used both these refractors? how is the stars and color correction compare across these scopes?

3. What is the best flatteners(not reducer) that worked best with these scopes?

4. Does the 2.5" focuser vignettes with the micro four thirds sensor ?

Thanks,
Deepan

PS:
1. I am comfortable imaging with long FL telescopes
2. I am being careful not to bring the discussion of FPL-53 vs FK61. Just the performance of these scopes
3. I am not looking to compare the focusers or the mechanical superiority of these telescopes

Respectful

James

Feb 28, 2022

I recently picked up an at115edt with the .8 reducer. I posted a first look video on my YouTube channel that includes raw and processed data.. with attention to the stars:

https://youtu.be/ahbPisP2CQw

I have never played with an AT130EDT but I suspect the performance with the stars/color is going to be very similar as they are pretty much the same design. One is just a bit bigger.

Never played with a photoline scope. It has fpl53 right? My expectation would be better corrected colors. I think the focuser on the photoline are a little different too.

Astronomics has a new version of the matching .8 reducer for the 115. Seems pretty good.. but be aware you have to remove the camera angle adjust to get focus with it (my video shows the issue).

No vignetting at all with a 4/3 sensor. I suspect it would be fine with a crop sensor too... the design of the new reducer was to accommodate larger sensors.

FPL53/FK61 is a major consideration. FPL53 is going to do a better job of controlling the color. I have one picture from my at115 on astrobin so far.. this was a test shot.. stars don't look great due to dialing in the backspace (took 3 attempts.. used data from all 3 attempts).. but it still gives you an idea of what the color correction looks like. There is a tiny bit of blue fringe around blue stars. It's not much though. To do better.. I think you'd have to spend a good bit more.

The focuser in the current shipping versions is okay. Holds my gear just fine. The entire focuser can be rotated.. mitigating the removal of the camera angle adjuster... but I think this feature also introduces a little sag. Pointing the scope down and tightening the set screws on the focuser seems to help.

I've only had this scope for a month.. I'll have a better idea about how it is in a few months

Helpful

David Nozadze

Feb 28, 2022

Have you considered a Takahashi? All of your options are fine telescopes, but Takahashi's are in their own class in color transmission, manufacturing precision, focuser quality and so on. They cost accordingly, though.

Clear skies,

D

Well Written

wsg

Feb 28, 2022 · Edited: Feb 28, 2022

Hi Deepan. I used to live in OKC so Astronomics was just a 20 minute drive away, which explains why I own 3 telescopes made by Astro Tech. First off let me say I have never owned scopes of similar sizes by any other brand so I can not compare directly apples to apples, but I have many images in my gallery taken with an AT 130EDT. You mention shooting galaxies so let me advise you to eliminate the AT115 from your list, only because of the difference in reach. You are going to need as much magnification as you can get.
I have never had a problem at all with vignette using any of my cameras including my asi294MC.
The AT 2inch field flattener works perfectly with the 130 and Astro Tech now has a dedicated thread on FF/reducer for the scope so there is also that to consider.
I have posted below some links to images taken with the AT130.

https://www.astrobin.com/z49ppy/
https://www.astrobin.com/0v09cn/?nc=&nce=
https://www.astrobin.com/7clrko/G/?nc=&nce=
https://www.astrobin.com/x204m1/?nc=&nce=

I hope this helps

scott

Helpful Engaging Supportive

kuechlew

Mar 1, 2022

No idea about the scope but the sensor with a 4/3" diagonal will not suffer from vignetting with a 2.5" focuser. Since you're on a budget I wonder whether you really need a flattener for an ASI294MM.

Clear skies Wolfgang

severinbb

Mar 1, 2022

Why not check out the Orion EON 115? See my profile for results. I think it's good value and I have no regrets getting it. At this point in my AP pursuits, I would buy it again.

Eddie Bagwell

Mar 1, 2022 · Edited: Mar 1, 2022

Just to throw in my two cents…I own the ES127 FCD-100 and I personally don't like the factory focuser that came with the telescope. It could be better. However, since I installed a ZWO Electronic Automatic Focuser on the unit I haven't touched the focuser once. The EAF does all the work with extremely small steps. So, unless you are planning on adjusting the focus manually, it is not an issue. Other than that, the ES127 FCD-100 is an exceptional telescope. Just saying.

Helpful Concise

Deepan Vishal

Topic starter

Mar 1, 2022

James:
I recently picked up an at115edt with the .8 reducer. I posted a first look video on my YouTube channel that includes raw and processed data.. with attention to the stars:

https://youtu.be/ahbPisP2CQw

I have never played with an AT130EDT but I suspect the performance with the stars/color is going to be very similar as they are pretty much the same design. One is just a bit bigger.

Never played with a photoline scope. It has fpl53 right? My expectation would be better corrected colors. I think the focuser on the photoline are a little different too.

Astronomics has a new version of the matching .8 reducer for the 115. Seems pretty good.. but be aware you have to remove the camera angle adjust to get focus with it (my video shows the issue).

No vignetting at all with a 4/3 sensor. I suspect it would be fine with a crop sensor too... the design of the new reducer was to accommodate larger sensors.

FPL53/FK61 is a major consideration. FPL53 is going to do a better job of controlling the color. I have one picture from my at115 on astrobin so far.. this was a test shot.. stars don't look great due to dialing in the backspace (took 3 attempts.. used data from all 3 attempts).. but it still gives you an idea of what the color correction looks like. There is a tiny bit of blue fringe around blue stars. It's not much though. To do better.. I think you'd have to spend a good bit more.

The focuser in the current shipping versions is okay. Holds my gear just fine. The entire focuser can be rotated.. mitigating the removal of the camera angle adjuster... but I think this feature also introduces a little sag. Pointing the scope down and tightening the set screws on the focuser seems to help.

I've only had this scope for a month.. I'll have a better idea about how it is in a few months

Thanks for the response James. Helpful review. Looking forward for your images.
BTW. We met in CN few weeks ago. On that Astrodon filters and EFW ad!

Deepan Vishal

Topic starter

Mar 1, 2022

David Nozadze:
Have you considered a Takahashi? All of your options are fine telescopes, but Takahashi's are in their own class in color transmission, manufacturing precision, focuser quality and so on. They cost accordingly, though.

Clear skies,

D

Thanks for the suggestion David. That's a plan for 2-3 years later. Right now, I do not have a dedicated backyard or accessible dark site. Until I figure out a dedicated dark site, I am planning to invest light on my set up.

Deepan Vishal

Topic starter

Mar 1, 2022

Hi Deepan. I used to live in OKC so Astronomics was just a 20 minute drive away, which explains why I own 3 telescopes made by Astro Tech. First off let me say I have never owned scopes of similar sizes by any other brand so I can not compare directly apples to apples, but I have many images in my gallery taken with an AT 130EDT. You mention shooting galaxies so let me advise you to eliminate the AT115 from your list, only because of the difference in reach. You are going to need as much magnification as you can get.
I have never had a problem at all with vignette using any of my cameras including my asi294MC.
The AT 2inch field flattener works perfectly with the 130 and Astro Tech now has a dedicated thread on FF/reducer for the scope so there is also that to consider.
I have posted below some links to images taken with the AT130.

https://www.astrobin.com/z49ppy/
https://www.astrobin.com/0v09cn/?nc=&nce=
https://www.astrobin.com/7clrko/G/?nc=&nce=
https://www.astrobin.com/x204m1/?nc=&nce=

I hope this helps

scott

Thanks for your inputs Scott. Great images with those Astro-tech scope.
I see that you are using Astrotech 1x flattener in your setup, Are you using compression ring to hold the flattener or are you threading it to the focuser?

Thanks,
Deepan

Deepan Vishal

Topic starter

Mar 1, 2022

No idea about the scope but the sensor with a 4/3" diagonal will not suffer from vignetting with a 2.5" focuser. Since you're on a budget I wonder whether you really need a flattener for an ASI294MM.

Clear skies Wolfgang

Interesting suggestion that I have not tried. But am curious to see what I am going to get without flattener. Will try and share the results.

Thanks
Deepan

Deepan Vishal

Topic starter

Mar 1, 2022

Why not check out the Orion EON 115? See my profile for results. I think it's good value and I have no regrets getting it. At this point in my AP pursuits, I would buy it again.

I think AT115 is the rebrand of the Orion 115. Am I wrong here?
I see they both use FK61. Orion focuser, are they compatible with ZWO EAF?

wsg

Mar 1, 2022 · Edited: Mar 1, 2022

Deepan. Factory compression ring with the the 2inch FF except on SH2-274. I have the threaded reducer ordered and coming soon from Astronomics, I can let you know how it is if you like.

scott

Deepan Vishal

Topic starter

Mar 1, 2022

Just to throw in my two cents...I own the ES127 FCD-100 and I personally don't like the factory focuser that came with the telescope. It could be better. However, since I installed a ZWO Electronic Automatic Focuser on the unit I haven't touched the focuser once. The EAF does all the work with extremely small steps. So, unless you are planning on adjusting the focus manually, it is not an issue. Other than that, the ES127 FCD-100 is an exceptional telescope. Just saying.

Thanks for the suggestion. I had a set up with ED102 and initially I suspected if EAF works with it. It did a fantastic job. But, the focuser sag was something that I couldn't work.
The amount I spent on the focuser, EAF, adapters and right flatteners, I spent more than an Esprit 100 that was easy and smooth.

That's the reason I have been avoiding ES. But I might have to add it to the mix if nothing works out!

severinbb

Mar 1, 2022 · Edited: Mar 1, 2022

Deepan Vishal:
Why not check out the Orion EON 115? See my profile for results. I think it's good value and I have no regrets getting it. At this point in my AP pursuits, I would buy it again.

I think AT115 is the rebrand of the Orion 115. Am I wrong here?
I see they both use FK61. Orion focuser, are they compatible with ZWO EAF?

The AT 115 sure does look similar to my EON 115, though I see a few small differences in the neck behind the main OTA and around the focuser. Even comes with the same case

Yes, no problems mounting the ZWO EAF to the EON 115. Here's the underbelly of mine (with 0.8 FR/FF and ZWO filter drawer). It all screws together.

severinbb

Mar 1, 2022

I will point out that my EON 115 with guide scope/camera, EAF, FF, main camera, etc weighs quite a bit, so a 130 will weigh quite a bit more. (It gets mounted to an Orion Atlas II EQ-G – a rebranded EQ6-R – which does just fine with this weight but I dunno about a lot more weight.)

Like you, I don't/can't observe at home, so I'm always setting up and packing up. That's why I leave everything connected to the telescope as in the photo above. I'm still young (ish) but I wouldn't want anything much heavier. Also I haven't felt the need for more aperature. (More focal length, yes, but that's another topic.)

FWIW.

Helpful

James

Mar 2, 2022

Deepan Vishal:
James:
I recently picked up an at115edt with the .8 reducer. I posted a first look video on my YouTube channel that includes raw and processed data.. with attention to the stars:

https://youtu.be/ahbPisP2CQw

I have never played with an AT130EDT but I suspect the performance with the stars/color is going to be very similar as they are pretty much the same design. One is just a bit bigger.

Never played with a photoline scope. It has fpl53 right? My expectation would be better corrected colors. I think the focuser on the photoline are a little different too.

Astronomics has a new version of the matching .8 reducer for the 115. Seems pretty good.. but be aware you have to remove the camera angle adjust to get focus with it (my video shows the issue).

No vignetting at all with a 4/3 sensor. I suspect it would be fine with a crop sensor too... the design of the new reducer was to accommodate larger sensors.

FPL53/FK61 is a major consideration. FPL53 is going to do a better job of controlling the color. I have one picture from my at115 on astrobin so far.. this was a test shot.. stars don't look great due to dialing in the backspace (took 3 attempts.. used data from all 3 attempts).. but it still gives you an idea of what the color correction looks like. There is a tiny bit of blue fringe around blue stars. It's not much though. To do better.. I think you'd have to spend a good bit more.

The focuser in the current shipping versions is okay. Holds my gear just fine. The entire focuser can be rotated.. mitigating the removal of the camera angle adjuster... but I think this feature also introduces a little sag. Pointing the scope down and tightening the set screws on the focuser seems to help.

I've only had this scope for a month.. I'll have a better idea about how it is in a few months

Thanks for the response James. Helpful review. Looking forward for your images.
BTW. We met in CN few weeks ago. On that Astrodon filters and EFW ad!

Don't think that was me.. I have never sold or purchased anything from CN classified.

Deepan Vishal

Topic starter

Apr 21, 2022 · Edited: Apr 21, 2022

Update!
I ordered the TS 130 Photoline 2.5 focuser and I received the scope couple of days back.
Initially I though the scope was miscollimated due to shipping. but it was the focuser.I made some adjustments to the focuser and I got to look at the stars to check, it was good and I could see concentric circles.
So no complains on collimation. But I'll confirm with more testing. Focuser is good. Holds the camera well, but I suspect there's a sag there in the focuser.

wsg

Apr 21, 2022 · Edited: Apr 21, 2022

Deepan Vishal:
Update!
I ordered the TS 130 Photoline 2.5 focuser and I received the scope couple of days back.
Initially I though the scope was miscollimated due to shipping. but it was the focuser.I made some adjustments to the focuser and I got to look at the stars to check, it was good and I could see concentric circles.
So no complains on collimation. But I'll confirm with more testing. Focuser is good. Holds the camera well, but I suspect there's a sag there in the focuser

I would send it back if there was any question about the collimation or focuser right out of the box. You paid 500 dollars more than an AT130ED to get a better telescope and you are not sure it even works at all never mind sure if it is better? I don't think anyone should have to accept any new telescope that isn't 100% assembled and factory QC'ed and perfectly ready to use upon receipt. I think that would also apply to almost any other large technical astronomy hardware.

scott

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