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Please help me choose an 8 inch scope ( No dobs )

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#1 Ghost332

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Posted 25 January 2021 - 08:41 AM

Hi All

I have spent the last couple of month researching after researching scopes, mounts, and I came to the conclusion that I am torn apart between a few models. My budget is 1000 euros MAX. It is already over by 300 of what I wanted to originally to spend.

To give you a little bit of a background, I have owned so far 3 telescopes, a 2.3" Refractor ( which I absolutely loved when I was 14) then recently a 6" goto reflector and then a 10 inch f/5 solid tube dob. In terms of use, the dob was quickly left behind due to its bulkiness, but I loved the 6" goto and that was used the most. So I am not really new to this hobby.

Since, I have sold all my instruments, but we have moved to a different country, where we have access to a bortle 3 sky in just 20 minutes of drive, so I am looking to get back to this hobby. I have removed the 8 inch dobs from the list because of the following reasons:

- The tube has to fit in the truck of the car. An 8 inch F/6 isnt going to unfortunately.

- This will be used both as a solo and a family instrument. Since we are going to observe planets and Globular clusters too, we need tracking for high magnification, so everyone can take turn comfortably, but we can live without goto since I can find a lot of objects myself.

Apart from dobs, I have looked at 8" SCT-s and 7" Maksutovs. Needless to say, those are expensive models and it is out of my budget. A Celestron nexstar 8se would cost me nearly 2000 euros here. Also, I don't really like their long focal lengths, since It could limit wide field observations.

So what's left. Well not much, but what I found that matches all the criteria are these models:

- Orion Skyview Pro 8 with tracking motor
- Sky-watcher Explorer 200p eq5 with tracking motor
- Bresser Exos 2 + 8 inch tube with tracking motor

I have also looked at mounts and OTA-s separately and I found the Exos 2 can tackle more weight than the rest EQ5 class mounts.
Then there is the newer EQM35 mount, which is too rated for 10kg-s. I have looked at iOptrion, but they dont have EQ mounts without goto which makes their mounts to expensive to hold an 8 inch tube.

For reference, I am well aware all the above would be at its limit to hold the OTA. (Luckily the wind here isn't much of a problem.) But I simply cannot find a better solution as of yet. These 8 inch tubes are just short enough to fit in the truck of the car. Also, EQ mounts can be upgraded relatively cheap with tracking motor, so we could still have the wonders of finding things ourselves, but the object wouldn't shift out of the view. I also like the idea of getting a skywatcher 130pds later, and I could use it with my mount to take pictures ( with up to 45-60 exposures). That would be enough for me to use in a bortle 3 sky.

So, my question is, which of these models would you recommend that is the most stable? Or, do you have any other suggestions that is within my price range?

Many thanks for all the answers in advance.

With kind regards,
Zoltan



#2 coopman

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Posted 25 January 2021 - 09:17 AM

Have you ever used a Newt on a GEM?  The eyepiece location/orientation is going to be all over the place unless you get rotating rings or make some Wilcox rings for it.  



#3 mt.jennings

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Posted 25 January 2021 - 09:46 AM

Your statement, "6-inch was used the most", is important.  KEEP and continue to use that scope!  A truly portable 8" is almost impossible. An older (orange) Celestron C-8  (on fork mount) comes closest (add an f/6.3 converter for wide field). That's why so many were sold; not optics, but portability!

And all items you listed are current production; learn to "cast-a-wider-net", and consider classic instruments... A 6-inch f/6 Newtonian fits a rear auto seat perfectly, leaving the trunk to hold a classic GEM; NOT a Vixen or Synta clone, but a beefy classic with 1" shafts or bigger.  John Allseits



#4 rob1986

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Posted 25 January 2021 - 09:52 AM

Seems I'm not the only one who doesn't want goto because its very expensive and of restricted benefit. It is probably pricing a lot of people out of the hobby.

What I wouldn't give for a fifty lbs class GEM with an RA drive and clutch!
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#5 rob1986

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Posted 25 January 2021 - 10:03 AM

Your statement, "6-inch was used the most", is important. KEEP and continue to use that scope! A truly portable 8" is almost impossible. An older (orange) Celestron C-8 (on fork mount) comes closest (add an f/6.3 converter for wide field). That's why so many were sold; not optics, but portability!
And all items you listed are current production; learn to "cast-a-wider-net", and consider classic instruments... A 6-inch f/6 Newtonian fits a rear auto seat perfectly, leaving the trunk to hold a classic GEM; NOT a Vixen or Synta clone, but a beefy classic with 1" shafts or bigger. John Allseits


Meades 826s are contemporaries and gave them stout competition for a reason. I've used them and packed them up in trunks, its not that hard, and newer piers have fixed the annoying fold up problem.

And forks are increadibly awkward to handle alone, the weight is all in the wrong direction, and you cant even use a small table to support it while you bind the saddle, just reach over where you cant even see and grope for the lockingnut

#6 Paul Sweeney

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Posted 26 January 2021 - 02:18 AM

What country are you moving to?

With your budget, I would buy used. Currently, here in Germany there is a Vixen GP with the Hal tripod for 180€. That would leave 800 for a tube and accessories.

An 8" Newt on a tripod based mount is really pushing things to the limit. I would suggest a 6" f/5. Much lighter and easier to handle, and you get a wider field of view.

If you get something like a Vixen Porta mount, then you have the ease of use of a dob on a collapsing, easy to use mount.

#7 BDS316

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Posted 26 January 2021 - 12:52 PM

my observing buddy has a TEC 200 on a very beefy AP go-to mount.  Highly recommended if you're considering a refractor.



#8 cuzimthedad

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Posted 26 January 2021 - 01:52 PM

Moving to the Mounts forum



#9 MitchAlsup

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Posted 26 January 2021 - 02:03 PM

Apart from dobs, I have looked at 8" SCT-s and 7" Maksutovs. Needless to say, those are expensive models and it is out of my budget. A Celestron nexstar 8se would cost me nearly 2000 euros here. Also, I don't really like their long focal lengths, since It could limit wide field observations.

There are only a few choices::

 

8" Newtonian on alt/az

8" Newtonian on GEM

8" SCT

8" refractor

 

a) the refractor is never going to be in your price range (unless you are walking by an estate sale and the broker walks over and hands you the scope)

 

b) you say the SCT is out of your price range and has too long a FL to boot.

 

c) this leaves you with an 8" Newtonial and a choice of mounts.

c.1) No 8" store bought Newtonian uses a truss assembly to pack and store in a small volume--they dont start trussing them until 12" (or so)

c.2) It is the als/az mount that makes the Newtonian into a DOB

c.2.a)alt/az mounts are smooth and stable 

c.2.b) alt/az mounts are inexpensive to manufacture

c.3) polar mounts {GEM, fork} are hard (i.e., expensive) to make vibration free

 

So, you have talked yourself into a corner with little room for escape. Perhaps you should reconsider something.....



#10 Zubenelgenubi17

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Posted 26 January 2021 - 02:48 PM

I've owned a SkyView Pro 8 (non-goto) for about 6 years now, and it's served me well. People will say various things about GEM mounted newts, but the tracking is really nice at public viewing sessions, and the non-goto motors consume very little power, allowing me to go an entire star party on one charge of my battery pack. Optically, the OTA is pretty unremarkable (neither exceptionally bad nor notably good). It does what you expect an 8" to do- collect a good amount of light. 1000mm is a good all-round focal length, and f/4.9 does have a few edge of field problems on some eyepieces, but it was perfectly usable with mid-range plossls and no coma corrector. I'm the third owner of mine, and I don't know if they're still made this way, but it's pretty robust. I'd put it in the back of the car, drive 3 hours to a star party, take it out, and it'd still be more or less in collimation.

 

The SkyView Pro mount isn't awful, but I don't love it either. One thing to be careful about is the RJ-11 plug for the declination motor; it's on a little piece of exposed PCB and can be damaged if you're not careful. (Make sure to set the mount head down with the connector on top.) An 8" OTA is definitely a bit under-mounted on it. For visual at low power, I have no complaints. Once you get past around 100x, the tube shakes take a bit longer to settle down than I'd like. That said, I regularly use 200x (or even occasionally 400x) on the moon and Jupiter; it's just not as great an experience as on my friends' rock solid setups (costing an order of magnitude more). I would certainly not use this setup for astrophotography. The SkyView Pro mount does not include a polar scope; if you want one, it's a $70 aftermarket add-on. If you're only doing visual, which is what I'd recommend this setup for (there's a reason it's not the "SkyImage Pro"), you don't really need it.

 

Would I recommend the SkyView Pro 8? That depends on what your needs are. If you want aperture that tracks on a budget, finding one of these used is an excellent option. If you want to do imaging, or little wiggles when focusing at high power are a deal-breaker for you, you'll want to look elsewhere. OTA + mount + counterweights total about 60lbs (27kg), and I usually make 3 trips in and out of the house when setting up, so consider the size of a scope like this too before committing to it. For me, looking for a bit more aperture and on a tight budget, this scope turned out to be a great buy.

 

Specifically in regards to your circumstances, under 500 eur, a used SkyView Pro 8 is a great option. If you've got 1k to work with, I would recommend you try and go for a more robustly mounted setup.

 

Edit:

As others have pointed out, with a GEM mounted newtonian, you will need to rotate the tube sometimes to put the eyepiece in a decent position. I have an extra tube ring around the tube above the forward-most load-bearing ring. This keeps the tube from sliding down when the load-bearing rings are loosened, making the process of tube rotation much less annoying.


Edited by Zubenelgenubi17, 26 January 2021 - 03:00 PM.


#11 SeattleScott

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Posted 27 January 2021 - 07:10 PM

I’m not saying it is cheap, but I use a Vixen R200 that I got used for a fraction of retail price on a AZ4 mount. The Vixen reflector is similar in length and weight to my buddy’s 6” F5. The built in coma corrector is hassle free. Weighs about 35lbs plus eyepiece. 8” of light grasp and resolving power, can frame Pleiades, light enough to pick up and tree dodge, high quality optics and holds collimation well.

Scott
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#12 Fitz8710

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Posted 28 January 2021 - 10:53 PM

I started off with an Orion 8 inch 4.9 203mm on a skyview pro. If using for visual it will suit you well. It is still pretty big though. If your not doing AP this is a very good scope for its price. For AP i have had to mod it extensively. Eye piece orientation would be a pain on GeM but i never had any issues loosening the rings and turning it when needed. Good price and decent mirror, what more can you ask for.


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