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Sky-watcher classic 6" vs 8" dobsonian for a first telescope

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#1 MoeLeo

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Posted 19 September 2023 - 07:51 AM

Hi all,

 

I'm looking at getting my first telescope and looking for people's advice and opinions on the matter. I'm basing my choice on "The backyard astronomer's guide" and the authors highly recommend Sky-watcher dobs as good beginner telescopes. I live in a suburban area and will most likely use the telescope in my back garden, although would like to keep options open to taking the telescope out to darker sites. I am a tiny person but my husband will help out with the lifting and setting up. I was going for the Sky-watcher classic 6" but was wondering whether going for the 8" would be worth it. Is the learning curve to learn to use them about the same? Are there any huge differences (aside from the apperture) that would sway you from buying one over the other?

 

If 8" is the way to go is the Sky-watcher classic the one to go for or another brand would be better?

 

Sorry many questions packed into this post but any and all help would be appreciated!



#2 Rigel7

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Posted 19 September 2023 - 08:03 AM

Go for the 8" if budget and weight allow it. Learning curve is pretty much the same for 6" and 8".
As for the brand, it doesn't really matter in regards to optics. Those scopes all use the same chinese-made mirrors.

Edited by Rigel7, 19 September 2023 - 08:07 AM.


#3 mapguy2

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Posted 19 September 2023 - 08:34 AM

First off, don’t buy from Amazon. These ship as two boxes I’ve heard many many stories of people only getting 1 of the 2; not getting the base for instance. I think Amazon fulfillment has issues with multiple part shipping. A company like Agena Astro Products would be better.

I will defer to others regarding whether to get the 8” or 6”. I wasn’t sure if I’d use my telescope more than a few times so I went for a 5” table top Dobson. Now that I’m hooked, I’d like to go bigger and 6” isn’t a big enough leap to justify upgrading.

#4 EsaT

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Posted 19 September 2023 - 08:39 AM

Here's excellent comparison of relative sizes of "standard" Dobsons. 6" is that "anorexic" looking one:

https://www.youtube....h?v=-qVXy7SDDo4

 

 

In 6" size SkyWatcher is on top with 2" size focuser allowing wide view eyepieces. (most 6" Dobsons have 1.25" focuser)

 

In 8" size SkyWatcher are second tier with seriously lackluster accessories compared to competition.

Apertura AD8 comes bundled with accessories worth 300 $/€ over SkyWatchers:

- Actual starter wide view eyepiece, instead of can't fit in Pleiades and no good in 1200mm focal length telescope 25mm Plössl.

- Neck saving RACI finder, instead of straight through neck pain finder.

- Dual speed focuser, which is good for both rough focusing and fine focusing needed for high magnifications. (single speed focuser is either very bad for one of them, or mediocre for both)


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#5 truckerfromaustin

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Posted 19 September 2023 - 09:28 AM

I am going to recommend an 8 inch dob with a GSO mirror.The larger aperture will open up the number of visible targets in the sky. GSO, Zhumell, Apertura, and a few other brands use them. They seem to be a little better than the other brands' products. I would suggest buying a used one in good condition. The money you save will allow you to buy the accessories you need, including a few better quality eyepieces. My 6 inch GSO has been flocked with felt and is carefully collimated. The image quality is almost as good as my 115edt refractor. There is some coma , but I can live with it. You can buy a coma corrector, if the blurred edges bother you.

Clear Skies,
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#6 Barlowbill

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Posted 19 September 2023 - 09:38 AM

If you get a 6" you will want an 8".  If you get an 8" you will want a 10".  Etc., etc., etc.  Light pollution will be your enemy along with Plossl eyepieces.  Having an option to use 1.25" or 2" eyepieces is huge.  2" for low power, wide field of view.

Cloudy Nights is the best move you have made so far.  Everything you will ever need to know is here.  You just have to search for it.  Best of luck!


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#7 Sebastian_Sajaroff

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Posted 19 September 2023 - 09:54 AM

Buy the largest telescope you can comfortably use, store and move around.


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#8 sevenofnine

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Posted 19 September 2023 - 10:01 AM

Welcome to C/N! flowerred.gif

 

+1 on EsaT's post recommending Ed Ting's video. He has many more that are very interesting. The 8" is the way to go if your husband will always help you with set-up and the all important break-down. If you want to stay up until 2 am and he's done at midnight then it could be a problem. Several advanced C/N members use the 6" version as their quick grab-n-go scope. Many of these scopes have different ways of operating the Alt/Az movements. Which is best is often debated on this forum. The basic Orion XT8 is the one that Ed recommends the most. It is his workhorse scope and he has a whole house and 2 car garage full of them. Good luck with your choice! borg.gif

 

https://www.telescop...yCategoryId=398.



#9 MoeLeo

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Posted 19 September 2023 - 02:10 PM

Thanks for the comments so far. I'm in the UK and it seems the brands that everyone has mentioned are not readily available or not available at all here. I think I've seen Sky-Watcher, Celestron, Meade, Explore Scientific and Bresser (there may be more, I'm not sure). I think I will have to do some more digging.

 

EDIT: I have found an Apertura AD8 equivalent here! StellaLyra 8"


Edited by MoeLeo, 19 September 2023 - 02:36 PM.

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#10 gnowellsct

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Posted 19 September 2023 - 02:20 PM

It depends on where you are in life and how much disposable income you have. If the kid has just gotten out of college and your expenses are lower maybe indulge in a Celestron CPC 8-in which would be a reliable go to instrument.

But the 8 inch dob which is almost universally recommended in these forums is an excellent option and less expensive.

Greg N
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#11 GoFish

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Posted 19 September 2023 - 02:24 PM

Only 2 reasons to avoid the 8”: slight increases in cost and size.

All other factors say go with the 8”.

#12 Echolight

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Posted 19 September 2023 - 03:41 PM

I've never used a 6. But I have a feeling that the dob motions, particularly azimuth, might be a little smoother.

 

Personally, out of all of the Asian dobs, if buying new, I would absolutely choose an ES Fitstlight. Or, garden makes me think across the pond,... Bresser Messier.

These have rings that let you rotate the scope for more comfotable eyepiece position. Also lets you move the scope fore and aft, up or down, for perfect balance. 

And the large altitude bearings are better also.



#13 vtornado

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Posted 19 September 2023 - 04:14 PM

Things to consider.

 

I can't recall if the bases are the same diameter???  If the bases diameters are the same, the base will weigh the same.

 

The tubes are the same length, but the 8 is probably 5 lbs heavier and 2 inches girthier.

I think the 8 inch tubes weigh in at around 20 lbs, 6 probably around 15.

 

If the six inch has only a 1.25 inch focuser that is a big minus.  Plastic focuser is a big minus too. 

 

F/8 is easier to collimate, keeps collimation longer, and is easier on wide field eyepieces,

however ... I have found that if I baby my 8 inch f/6, meaning pick it up gently, carry it gently, put it down gently the collimation holds.

 

Since the focal length is the same, 8 inches will have better views of every object than the 6.


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#14 Anony

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Posted 19 September 2023 - 04:25 PM

Things to consider.

 

I can't recall if the bases are the same diameter???  If the bases diameters are the same, the base will weigh the same.

 

Depends on the model, but I think the bases are usually exactly the same between 6 and 8? It's just that the 8" is a bit fatter and heavier.

 

I'd say go 8" unless the extra 5lbs or so is a deal-breaker (and for most it won't matter). Typically it takes two trips to move a 6-8" dob regardless. So it's not like the extra weight usually is a problem. 

 

The exception to me would be if a person was going for a short 6" dob (tabletop flavor). There it's noticeably lighter I expect.  Then it just comes down to how much a person wishes to lug around.

 

I never really considered the 6 or 8" dobs ideal travel scopes, so keep that in mind... but if you are using your husband's muscles, it's sort of his problem to deal with. 

 

As for model differences, not entirely sure what comes with the sky watchers. Look for a 2" focuser, fan, etc.  There are also Celestron Starsense dobs to consider.... starsense is pretty neat... but their dobs don't usually have much in the way of extras. One option some go with is to buy a cheaper LT starsense scope and move the phone mount over to the dob.


Edited by Anony, 19 September 2023 - 04:30 PM.


#15 56S

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Posted 19 September 2023 - 04:43 PM

I'd recommend the GSO/Zhumell/Apertura 8". They are all made by GSO and at least some are made in Taiwan. Never thought I'd say this but Taiwan made is better quality.

Find one with the 2" Crayford style focuser and if possible try to get a 90° finder scope. For a few more dollars you can get an additional finder scope base and install a green laser pointer. Be very careful using the laser pointer that there are no aircraft anywhere near when you use the laser.

I have a GSO 6" on an equatorial mount and a Zhumell 10" dob.
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#16 vtornado

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Posted 19 September 2023 - 04:45 PM

I sold my 6 to buy an 8.

 

I being a fit older man, I  could carry the 6 out the house door with one hand by the front handle.  8 is too big to to this, it has to go through doors in pieces.  I can carry the 8 as a unit,  a short distance when outside.  I do this for tree dodging.  I sort of miss my six.  If I found another on craig's list for a good price I would get another, so I have a scope that goes out the door quicker on questionable nights such as limited time, patchy clouds, cold or mosquitoes.  If  I only had one telescope and was paying full retail price I would choose the 8.

 

Another reason I sold my my six was it had the wonky 1.25 inch plastic focuser.  The focuser had a lot of slop.  I was also afraid of hitting a door with it and snapping it off. replacement parts are non-existant.


Edited by vtornado, 19 September 2023 - 04:59 PM.

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#17 Inkie

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Posted 19 September 2023 - 05:49 PM

Save yourself the almost, not absolute, but highly probable, next step of wanting to upgrade your scope's capabilities and your enjoyment by procuring a larger scope next time....skip the smaller scope and go bigger.  It's almost always what we do...go bigger, chasing the gee-whiz views of our dreams.  As an earlier responder said, you'll want an even bigger reach in time, but if you skip the 6", you'll save yourself at least that one step of evolution.  It's what I have done, and I have no regrets. 

 

If my wife of 60 years can pull a yard wagon laden with cordwood via a rope around her waist, and push the same weight in a wheelbarrow in front of her at the same time, 40 yards from where the truck dumped our two annual cords to where I was stacking it in a shed, I think you will probably not have much of a problem with an 8" scope, certainly if you move the tube and base separately.  If you can lift a 40 pound suitcase in and out of a car, you can handle a modest-sized Dobsonian. 

 

There is nothing wrong with a more modest 6" scope, and it will yield many delightful views.  But believe me when I say there's a virus in the hobby that afflicts each of us in time, and that virus commands the host to reach further, look for better views, better eyepieces, more accessories, get into digital imaging, and so on.  Not all of those, but a lot of those.  And, there are many 'gurus' in the hobby who claim that they routinely recommend the ubiquitous 8"er to people who want to get into the hobby.  When funds are dear, sure, be careful and be more realistic. You can upgrade later when it makes sense to do so.  But if you're keen, ready, and in good financial straits, my recommendation would be to start with a more capable scope and go from there. 



#18 MikeTelescope

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Posted 19 September 2023 - 10:20 PM

Get the 8.  The length of the tube is about the same as the 6, the weight is not much more, and the bases are about the same.  You will see more with the 8.

 

The Sky-Watcher 6 has a 2" metal rack-and-pinion focuser.  A comparable 6" Dobsonian, the Orion XT6, has a 2" Crayford focuser.  If you don't know what that means, don't worry, both focusers are fine, but the Crayford is smoother and is less likely to get sticky and sloppy over time.  Both the Sky-Watcher and Orion 8" Dobsonians have 2" Crayford focusers.  

 

The Orion 6" and 8" Dobsonians use a spring tension system, while the Sky-Watchers use a lateral friction system.  I prefer the spring tension system.  The motions of the scope are smoother.  

 

Check the used market first, these are fairly common scopes that can be found on Facebook Marketplace, Craigslist, the Classified section of Cloudy Nights, or whatever other resource you would use to find used items in your area.  New scope prices went up significantly in the last few years, and there is a large used market of scopes that people bought during the pandemic that they used just a few times.  



#19 star acres

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Posted 19 September 2023 - 11:21 PM

It helps to understand that some decisions are too big for the human mind. Fall back on Indian principles. 6 or 8 inch telescope? Look for a sign. You will know the answer when it comes to you.
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#20 Slip

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Posted 19 September 2023 - 11:41 PM

Go with the 8 inch. They are easy to get rid if if you ever want to upgrade and it may be the last telescope you buy. If you do want to upgrade later you will probably be in the 12 inch range.

 

Just about all the Dobsonians are made out of 2 plants in China so just look for the best deal.

 

Aloha and Clear Skies. waytogo.gif



#21 beecee

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Posted 20 September 2023 - 01:43 AM

Hi MoeLeo,

Well, you’ve certainly got a flood of information to wade through! smile.gif

 

Depending on where you’re located, if you have a good astronomy shop in reach, it’s worth it to go and actually touch/lift some of the ones that have been discussed. 
 

You mentioned that you might travel with the scope. While it’s absolutely possible with a solid tube 6” or 8”, the Skywatcher Heritage 150P (6”) is a nicely portable one. Their 8” and up collapsible ones get pretty unwieldy.

 

I started out with the 150P, and while it’s got its issues as all scopes do (said issues documented on various threads here), you might find it fits the bill, especially if you or your hubby like to mod equipment. It was a good scope with which to learn technique even though you’ll see more with an 8”. I actually found the limitations allowed me to focus (ha) on what I COULD see.

 

YMMV, but thought I’d throw this out there. Great choice of book, BTW! I can recommend “Turn Left at Orion” as well, as a good way to start learning the sky.


Edited by beecee, 20 September 2023 - 03:46 AM.


#22 TheChosen  Happy Birthday!

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Posted 20 September 2023 - 04:21 AM

The 8" is a very clear optimum telescope that a beginner can buy, especially compared to the 6". I have the 8" and do not want anything smaller (or bigger) for now.

 

It will likely have a much better quality focuser and the ability to utilize 2" eyepieces better than the 6".

 

The 33% higher resolution and 78% more light is also very important.

 

The price difference between the 6" and 8" in my view does not justify going for the 6".

 

Someone said if you got the 8" you may want the 10". Not really. In my case I would not want the 10" as my beginner telescope.

 

In many cases the 8" stays with you for a long long time, possibly forever.. They simply get sold after few years of enjoying the hobby or kept as a 'lightweight' scope when going bigger to a 12" or 16".



#23 gene 4181

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Posted 20 September 2023 - 08:21 AM

 Which one will be easier for you  too handle .      



#24 MoeLeo

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Posted 20 September 2023 - 08:30 AM

Thanks everyone for your comments and recommendations! I've done a little bit more digging and have decided I'll probably go with the 8". As for brand I'm kind of leaning towards Stellalyra (Apertura/Zhumell) instead of Sky-watcher. Eventhough it is a little more expensive it comes with a few more things that seems beneficial. It is currently out of stock which will give me some time to sit on this decision and do some more digging.

 

Thanks again! waytogo.gif


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#25 TheChosen  Happy Birthday!

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Posted 20 September 2023 - 08:57 AM

Thanks everyone for your comments and recommendations! I've done a little bit more digging and have decided I'll probably go with the 8". As for brand I'm kind of leaning towards Stellalyra (Apertura/Zhumell) instead of Sky-watcher. Eventhough it is a little more expensive it comes with a few more things that seems beneficial. It is currently out of stock which will give me some time to sit on this decision and do some more digging.

 

Thanks again! waytogo.gif

As an owner of a Sky-Watcher 8" I approve of this message ;) . I will never forgive Sky-Watcher for bundling a 25mm Plossl instead of a 30mm 2" eyepiece. The 2" is FAR better and FAR more useful to a beginner. The 32mm 2" I have is my most used eyepiece.


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