Which long(ish) FL scope would you recommend for me? - Forums

Topic starter

Sep 22, 2022 · Edited: Sep 22, 2022

Hi guys, I've been imaging for 6 years now and am happily continuing to do so. I would consider myself very experienced (with the gear I have). You can find that in the description. Very happy with my Esprit 100 / ASI294 combo

For many years I've thought about adding another scope to my little collection. Of course I also took a look at what's out there knowing full well everybody is just marketing their stuff and I would love to hear some experiences from other imagers. Here are my "requirements":

I want to keep using the ASI294 bin2 to take advantage of lower read noise and collection area and want to get to between 0.67"/px - 1.00"/px, so roundabout 925mm - 1400mm focal length
I would love the scope to be below 12ish kg - I packed some additional stuff on the Esprit recently with 12.5kg and the mount guided just fine as always. But the pier tripod I use will start being a culprit and I would need to buy a different one
I'm not afraid of collimation or anything. Anything can be learned. I would like the scope to hold the collimation for a while though, I disassemble and setup my setup every night
I am from Germany so some things are hard to get here right now
Screwed connections from the focuser are a must have for me - I do not feel comfortable at all with pressure clamps with thousands of euros hanging on that one
Ideally somewhere between f/4 and f/5.5 would be good, but if scope is exceptional otherwise I may not pay too much attention to this. I regularly image for 24h+ per image
I'm a pixel peeper and am very sensitive to star shapes not being right. Sent back a RASA8 for that reason, love the Esprit 100 though
Price is not that big of an issue but quite honestly I do not feel like I would shell out more than say 3500€ for the scope
I would like to avoid upgrading / changing the mount as the AZ-EQ5 is nicely portable still.

Here are some ideas:

8" Lacerta Newton without Name (bought my Esprit 100 from them, VERY positive impressions from the past contacts), would then need to get a paracorr type 2 to get to required FL but unsure about screwed connections
8" Teleskop Express UNC f/5 Newton with GPU - more price contious option
8" Teleskop Express N-AG8 - has a paracorr clone, pretty much similar scope as above with screwed connections but more expensive and other hardware seems worse to me (e.g. 2nd holder)
8" Edge with .7 reducer - seems too expensive for what you get, correction of reducer seems questionable
8" RC with AP .67 reducer, not sure about correction here, scope seems to be mechanically unsound from what I read. As I understand the focuser is attached to the primary mirror holder, that sounds like a recipe for disaster

Some additional thoughts:

I'm not even sure about needing a carbon tube. I use focus filter offsets anyway and have a motorized focuser. The only objective thing I would gain is more net imaging time if I rarely need to have a complete autofocus run from my perspective
I actually would love a 10" f/4 newton but it just seems too heavy to me.
Sharpstar SCA260 also seems interesting but again very heavy.
I'm always sceptical about the real weights by the way with dovetails and everything. I'm not sure every supplier quotes the same weights (only scope, with rings, with rings+dovetail, etc)
I also like refractors, but they're all so slow :-/

Which scopes did I not consider that I should look at closer?
What would you chose and or what is your experience with some of these? Would you recommend them for someone like me?

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Andy Wray

Sep 22, 2022

Not what you asked for, but I'm personally yearning after a Takahashi epsilon 160 or 180 ED. I have a Skywatcher 200PDS which is 906mm F4.5 after adding the coma corrector, but not tad sharp on the stars. The Skywatcher Quadros may be worth a look or maybe the TS Optics carbon Newtonians.

andrea tasselli

Frequent contributor

Sep 22, 2022 · Edited: Sep 22, 2022

I'd go for a 200mm f/5 newtonian, either a Lacerta or a TS. If you plan to autofocus on the go, like I'd do, then you won't need a carbon tube either. The focuser choice is yours to make but I'd reluctant to part with 1 grand for a FT. A Baader Steeltrack would do in my humble opinion. The TSGPU is a perfectly good fit and you can also screw it to the focuser, if you feel inclined to do so. I do not. This said, I'd upgrade your mount first and then think of the largest telescope I can fit on it.

P.S.: if you feel a little adventurous is another possible scope that would fit the bill:

https://www.teleskop-express.de/shop/product_info.php/info/p9630_Orion-VX10-Newton-Reflektor-Teleskop--Oeffnung-250-mm-f4-8.html

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Brian Meyerberg

Sep 23, 2022

I had an 8” RC and sold it. Used it once and wasn’t satisfied with the bloated stars and I found it very difficult to collimate. I tried all tools that probably cost more than the scope itself. 😂

Bought the EdgeHD 8” with the Celestron .7x reducer and love it. Here’s my first image with it:

Triangulum Galaxy

it might need some collimating but it’s simple with the Edge HD and a star at Zenith. I believe you can find it with the Reducer for 2K. I did add a Moonlite with the Version 2 Motor and it works fantastically. I’m adding an Eagle 4 S and ECCO2 next week. I highly recommend it.
good luck in your decision.

Brian

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Reg Pratt

Sep 23, 2022

I've had the Edge8 and 2x GSO 8" RC in the past. I'd get the RC again in a heart beat. They were well constructed , collimated fast, and held collimation for months at time through thousands of miles of traveling to dark site. In a 6 month time period I only had to make minor tweaks to the secondary a couple times. Never had to touch the primary after initial collimation. Be aware though that the 0.67x reducer is only a reducer and doesn't correct curvature. Not a huge deal with a chip the size of the 294 but still something to be aware of.

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Connor Kessler

Sep 23, 2022

I'm a refractor fanboy at heart, but I have heard great things about the EdgeHD 8". From what friends and other imagers have said to me, it seems to be the best bang-for-buck buys when it comes to aperture and FL.

That said I do not have one so I cannot contribute my own opinions on it. When I did want a bit more FL than my Skywatcher ED 80 and WO GT71 I decided to stick to a refractor.

I went with the Orion EON 130. Orion is/was a local company here so customer service has been impeccable and the fellow at the Heavenly Backyard YT channel had great opinions of it. It has a native f/7 @ a 910mm FL. To utilize the full FL I use a Hotech flattener which has been one of the best accessories I have ever purchased. If I want a larger FOV, I swap down to a different reducer. Orion sells a .85x reducer and Starizona sells a .65x reducer. I find that my single scope now easily accommodate the vast majority of targets. I'm pretty new at imaging galaxies, but it has served me well.

It might also be worth noting that my 2 cameras are the ASI294MM and MC respectively, so I can tell you that the camera you have has been bliss with the EON 130.

Some folks may turn up their nose at the fact the EON 130 does not use official FPL-53 glass and instead uses a different glass for the triplet glass. Personally, I have not had a single issue with colors being poorly sorted that wasn't entirely my own error.

I'm reluctant to share my images on this thread because I'm a country mile outside the realm of what I would consider especially skilled or advanced in this hobby, but this is a picture of the Eagle Nebula I took with my ASI294MM this past month using the EON 130 at it's native FL. I'm pretty garbage at star processing still, but generally I was blown away at the detail I was able to pull out of the Pillars of Creation with only 7 hours of integration with the EON 130/294MM combo.

Sorry this was long winded, but I hope this helps somewhat.

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Fabio Guerceri

Sep 23, 2022

I have an RC8 with focal reducer 0.67, it's a good tele, first I had a SW 200/1000 newton which I sold for a C9.25.
The advantages over the previous two are:
- it is more comfortable and balanced than the newton because it has the focuser behind it and therefore always remains in the same "zone"
and for the same weight it is shorter, therefore less leverage on the frame.
- compared to the C9,25 it has a fixed primary mirror, while in the Celestron this moves with the focuser creating
problems of attitude and therefore of focus (mirror flop) during the photo session.
- compared to the C9,25 it does not have a correcting plate that closes the tube, so no fogging and acclimatization problems
short.
- produces a beautiful star field certainly comparable to a well corrected Newton, but not compared to C9.25
much scarcer (puffy stars)

Collimation is a bit of its weak point, because it is sensitive (parabolic mirrors) and has three degrees of freedom:
primary, secondary and focuser, but do not be scared the collimation of the factory / seller already gives good results,
and if you then have to collimate again, after a bit of tests you get a correct collimation to make good photos and it holds very well.
I collimated the first time in a year, unless you drive it on broken roads.
The mechanical quality, (like other instruments of the same level), can be a problem because it is an inexpensive Chinese tele (like many others), and being sensitive to collimation errors these defects impact more than a Newtonian.
But if there are little things that a specialized laboratory solves.
The quality is compatible with the price.

I don't know about refractors.

Fabio

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Sven Hoffmann

Topic starter

Sep 24, 2022

Thank you all for replying. I'm really surprised by your responses. I have one particular question to those who owned and sold an f/5 newt: WHY did you sell it?

I'm still leaning to buy that at this time.

Andy Wray

Sep 24, 2022

andrea tasselli:
P.S.: if you feel a little adventurous is another possible scope that would fit the bill:

https://www.teleskop-express.de/shop/product_info.php/info/p9630_Orion-VX10-Newton-Reflektor-Teleskop--Oeffnung-250-mm-f4-8.html

FWIW: The focusser on that Orion looks just like the one I bought for my 200PDS. I've now removed it from the 200PDS and gone back to the stock focusser because it only had one screw for tightening the brass compression ring and another one for its extending barrel. I found it impossible to get rid of tilt of my coma corrector.

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Stuart Taylor

Sep 24, 2022

andrea tasselli:
The focuser choice is yours to make but I'd reluctant to part with 1 grand for a FT. A Baader Steeltrack would do in my humble opinion.

Totally agree with this. I think FT is OTT. I have the Diamond Steeltrack on my Edge HD and it's excellent.

Dale Penkala

Sep 24, 2022

Sven Hoffmann:
Thank you all for replying. I'm really surprised by your responses. I have one particular question to those who owned and sold an f/5 newt: WHY did you sell it?

I'm still leaning to buy that at this time.

Hello Sven,
To answer this question in particular, I kept moving up in size to the 12” f5 DBA Certified Newt that I have now on my main rig. I shoot mainly with newts, but do have an 80mm for wider fields of view.

But to your original question, As many here have already stated I think an 8” f5 newt would be my suggestion and I would consider an 8” HD from Celestron. IMHO I don’t think you would want to go much bigger with that mount as (if my memory serves me correctly) its only got an 30lbs weight capacity. I had an Orion 8” f5 newt and with everything on it it weighed in at 22lbs. I had this on a bigger mount so for me weight wasn’t a factor. That said, I’d consider a Sky watcher however it is an f4 and if your a pixel peeper as I am the TS line have excellent reputations from what I’ve heard.

I won’t post pics but if your interested here are a few images with my newts. The image of m51 was with my 8” but its not a fair judge with the stars as when I had that setup it was on a problematic mount that in the end got rebuilt and then moved to a 10” newt.

12” / Stephans Quintet: https://www.astrobin.com/v04kd2/B/
12” / M76: https://www.astrobin.com/k0zbvd/D/
10” / M81: https://www.astrobin.com/ulgbxj/F/
8” / M51: https://www.astrobin.com/ulgbxj/F/

Best of luck

Dale

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Torben van Hees

Sep 26, 2022 · Edited: Sep 26, 2022

I think your assessments are spot on. Let me add a few things - I‘ll specify which is hearsay and what is my own experience.

I do not really recommend the 8“ GSO RC. As you observed, the design is flawed and you will have shifting collimation when the scope moves around the sky. It will not be as visible with the ASI294 in binx2 probably, though, and the 0.67 reducer will work very well with that camera. The stock focuser isn‘t very good, too. My RC lost collimation after a road trip. Took me months to get it back in shape, collimation is orders of magnitude more difficult than a newt. I have a CFF RC now, the reduced hassle due to better mechanics was well worth the premium, but it‘s too heavy for your mount.
The GPU coma corrector is very good up to APS-C. I have no experience with the Paracorr, but people tell me it‘s even better.
The UNC Newtonians keep the stock GSO primary mirror cell - consider an ONTC instead. There‘s quite a few people in Germany who do not like their UNCs.
With the AZ-EQ5 a 8“ Newtonian will be the limit of its capacity, and f/4 will be better than f/5. It‘s not so much the weight but the sheer bulk. Any wind will deteriorate the image. My AZ-EQ6 could just barely handle 10“ f/5.
My dealings with Lacerta have always been excellent experiences.
I have not read of a bad experience with either the ONTC or the Lacerta NoN.

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lucian_nicu

Sep 26, 2022

Sven Hoffmann:
Thank you all for replying. I'm really surprised by your responses. I have one particular question to those who owned and sold an f/5 newt: WHY did you sell it?

I'm still leaning to buy that at this time.

Because I could only use it at home, in the backyard. As it happened, if I wanted to "image" from a dark sky location, where the roads are not really of good quality, I had to expect some mediocre results (decent at most, but by no means great), in especially regarding the shape of the stars. And after each session away from home, the collimation had to be redone. In theory it doesn't seem that hard, but honestly, it was getting frustrating.
I had a Vixen rss200 8' F4 (the most frustrating telescope), a Skywatcher PDS 6' F5 (perhaps the most stable, but also the one with the lowest quality) and an Orion UK VX6 150/750 (not the most comfortable, but with an impeccable mirror quality).