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10" Dobsonian recommendations


Tot
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If the bank will play ball I'm hoping to get my second scope soon. I think I want a big dob this time to gather as much light as possible. My current scope is a 130P reflector and I crave more aperture for DSOs.

There are Skywatcher, Orion and GSO 10" dobs around. Any preferences from existing owners and users? Ideally I want to be able to set up in as short a time as possible plus I will have to move the base and OTA every time I use tbem. So reasonably easy to carry into and around the garden and quick to set up are requirements.

The Skywatcher ones seem to fit the bill fine but what about the other makes? Are there ones that stand out as being better made with better quality optics, focusers etc?

I currently use a Synscan Alt-Az GoTo mount. Most times it's fine but I like the idea of the freedom to just point the scope to any point manually. But with a fully manual dob I think I might miss the ability of the scope to find more difficult targets and track them. It may be that I can stretch to a GoTo dob. Are you able to use these without the GoTo set up and just use like a classic dob, no electrics? Then at other times "plug in " and use the goto and tracking? I like the idea of star-hopping on a classic dob but think the tracking and goto capabilities might be very handy too for certain occasions. Do the motorised dobs take very much longer to set up than the classic ones?

Ok any and all advice is most welcome. Thanks.

Tot

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The 10" Skywatcher/Orion/GSO Dobs are excellent value for money.

For extra money you can buy an Orion Optics Dob, which will be lighter than the above three scopes and you will get certified optics - up to 1/10 wave which is more than enough for our UK skies.

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The GoTo option with a SkyWatcher does allow it to be used without a battery but its very stiff as your pushing i assume the motors round as well as the Dob, you can however use it in a non GoTo mode just by using the handset and slew to parts of the sky you want to look at, I normally push it round by hand and then either use the GoTo or slew by hand, it remembers where it is as there are some encoders on the motor assembles so a push then GoTo still works, i move mine in 2 parts and set-up time including Collimation a couple of minutes this includes a 2 Star Alignment, the GoTo is extremly accurate once this is done....i have a 14Ah Tracer battery this gives around 16 hours between charges...i am very happy and would only change it for the 16" version...

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The GoTo option with a SkyWatcher does allow it to be used without a battery but its very stiff as your pushing i assume the motors round as well as the Dob, you can however use it in a non GoTo mode just by using the handset and slew to parts of the sky you want to look at, I normally push it round by hand and then either use the GoTo or slew by hand, it remembers where it is as there are some encoders on the motor assembles so a push then GoTo still works, i move mine in 2 parts and set-up time including Collimation a couple of minutes this includes a 2 Star Alignment, the GoTo is extremly accurate once this is done....i have a 14Ah Tracer battery this gives around 16 hours between charges...i am very happy and would only change it for the 16" version...

I like the idea of being able to easily swap between pushing/nudging the tube manually then using the handset. Some times though I won't be bothering with 2 star alignment or goto and will just want to do everything manually. Other times, after an alignment, it would be so good to slew manually AND afterwards use the goto with the mounts encoders knowing exactly where the scope is pointing.

Does anyone know how the Orion Skyquest Intelliscopes are in this regard?

Thanks for the info already provided!

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The difference in optics between the brands in negligible, OOUK excepted. All of the focusers are okay, but the dual speed GSO is better and the ES dual speed is really nice.

The SW bases are much larger and heavier than the GSO clones. Personally, I found the SW GOTO to be awful at worst and temperamental at best. Others have had no such issues, but there's a very long thread on here by Dr. Robin detailing his attempts to get his to work. I lacked his commitment, printed a degree scale for the azimuth base, bought a Wixey for Alt and just pushed the thing around. Fortunately, the tracking was pretty good, so once I found something, that part worked rather nicely.

If size and portability are an issue, then the Explore Scientific 254mm Ultra Light Dobsonian has them all beat. It packs down into a space smaller than the bases of the other Dobs, which still leave you needing to find somewhere to put the OTA.

Russell

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very good scope and great mirrors, and moonlite focuser to boot

Plus the seller has had a very positive established input on here, so you will be purchasing from a dependable seller, worth the trip to Cornwall. Skywatchers and Co are very good, particularly for the cost at retail, but if you can get your hands on a good spec OOUK VX tube and their dob mounts, you may never look back.

Edited by scarp15
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The more I keep searching the more I think, if buying new, the Orion XT10g might be the one to go for...

If GOTO is a must for you then it's either the Orion XT10g or the Skywatcher 250PX Flextube GOTO both of which are made by the same manufacturer, contain the same optics and I think use the same GOTO system.

Personally I'd go for the Orion VX10 and happilly trade GOTO for superb optics but I know my way around the sky so thats easy for me to say :smiley:

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Plus the seller has had a very positive established input on here, so you will be purchasing from a dependable seller, worth the trip to Cornwall. Skywatchers and Co are very good, particularly for the cost at retail, but if you can get your hands on a good spec OOUK VX tube and their dob mounts, you may never look back.

ever :grin:

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Q:  certified optics - 1/10 wave 1/4 wave ?

Although nothing arrived in my  documentation, and  considering the next aperture step,  what specifications are default for the 8" 10" and 12" Skyliner mirrors.  Is it safe to say my 8" is a 1/4 wave PV??

Is there a chart/scale to better explain this theory.

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Some optics professionals test their mirrors at very high mag to prove them, no doubt they do interferometer etc tests as well. If anyones mirror has ever given excellent high power views, then it is good, regardless if it comes with test reports or not. I hear SW makes good mirrors. The faster the f ratio, the more the likely hood of getting an avg mirror or worse increases I think. Of course buying a mirror from a maker that Zygos them and provides data reassures the fast mirror buyer.

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I reckon the GSO and Skywatcher mirrors run somewhere between 1/4 and 1/6th wave PV. There might be a few that fall outside these paramaters occasionally. GSO often quote a 1/12th wave figure but that is RMS rather than PV. 1/12th wave RMS is just about equal to 1/4 wave PV.

Strehl ratio is another measure often quoted and is said to be more useful in determining the optical quality of a mirror. More reading here:

http://www.rfroyce.com/standards.htm

What Orion Optics give you is some evidence of surface accuracy of your mirror and can meet your specified requirements, for a price.

What matters most is what the scope is like for you. I've had great views through all 4 brands of scope mentioned here :smiley:

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If GOTO is a must for you then it's either the Orion XT10g or the Skywatcher 250PX Flextube GOTO both of which are made by the same manufacturer, contain the same optics and I think use the same GOTO system.

Personally I'd go for the Orion VX10 and happilly trade GOTO for superb optics but I know my way around the sky so thats easy for me to say :smiley:

I suppose it's not so much the GoTo I really want as the tracking ability when powered on. The idea of also being able to slew by hand and then use tracking or GoTo if previously aligned does appeal though. ;-)

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Tracking with an undriven dobsonian is not difficult - many of us do it up to 250x - 300x and more without too much of an issue :smiley:

Skywatcher used to do a tracking but non-GOTO version of their dobs but I'm not sure if that option is still available ?

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Since you live in Nottingham, you're on the doorstep of David Lukehurst, a well-known maker of large portable truss dobs with a choice of 1/4 or 1/10 mirrors. His range starts at 12". If your budget would stretch to it could be worth giving him a call. 

Hope you find what you're looking for

StevieO

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Since you live in Nottingham, you're on the doorstep of David Lukehurst, a well-known maker of large portable truss dobs with a choice of 1/4 or 1/10 mirrors. His range starts at 12". If your budget would stretch to it could be worth giving him a call. 

Hope you find what you're looking for

StevieO

It may be worth pointing out the one I got made by him was a 10 inch.  Mine was not listed on his site but it seems he will make variations on the theme.  It was worth every bit of over time to save for it too.  No regrets :)  Very solid scopes, it has not needed collimating yet (nearly 1 year on & maybe ~30 set ups).

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It may be worth pointing out the one I got made by him was a 10 inch.  Mine was not listed on his site but it seems he will make variations on the theme.  It was worth every bit of over time to save for it too.  No regrets :)  Very solid scopes, it has not needed collimating yet (nearly 1 year on & maybe ~30 set ups).

Must be nice to own a scope thats almost bespoke as well :smiley:

I observed through a 20" David Lukehust dobsonian once - I won't forget those views in a hurry ! :grin:

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