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Help required Orion Optics UK VX12

guillaume320

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guillaume320

guillaume320

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Hello from Belgium,

I'm new here and about to buy a telescope... 

It's been several weeks I basically did nothing else than look for what would best suit my needs.  At the moment, I'm leaning towards the Orion Optics VX12 f4 on dobson mount.  This looks to be the combination of aperture and transportability that I'm looking for. Like someone on this forum said on his review: 'a 12" that performs like a 13" but only weights like a 10"'.

So considering this is a very fast scope at f4, I have been told I would also need a coma corrector. For that, I'm looking at Paracorr from Televue.  This, combined with the future eyepieces I'm considering (Nagler 13 T5, Plossl 32, Delite 9 and barlow x2) leads me to my query:

 

I've come across several reviews mentioning not having enough back focus on the one provided by Orion Optics.  Considering I'm a visual observer only, and given the eyepieces I've mentioned above (Are they a good choice by the way??), will the ACU-2S focuser provided as standard on the VX12 be up to the job??

I'm looking forward to your enlighten opinions :)

 

By the way, this will be my first telescope. So far I only observed through hand held binoculars (in which I saw many things I have to say!), and I have no 'difficulty' in finding my way around the night sky... I've been more of a 'passive' stargazer so far, but now I feel is the time to invest a bit more in this hobby.

 

Best regards,

Guillaume

 

 

 

 

 

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Peter Drew

Peter Drew

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Assuming you are considering buying new, I would recommend you ask OO to check that the telescope will come to focus before they send it. It would save both parties a lot of hassle otherwise!     :icon_biggrin:

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Moonshane

Moonshane

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Every OOUK scope I have ever had does not have adequate back focus for visual observations.  The very simple solution is a 35mm extension tube. That said a paracorr takes the focus point in about 18mm so when using a paracorr with my 12" f4 I don't use an extension but just pull the paracorr out about 20mm. Not enough in focus is a bigger problem of course.

I agree with Peter though. Send the paracorr to Orion Optics and get them to optimise the system.

I also agree with your choice it's a superb scope. I generally buy used as the new prices are too expensive for me.

Here's mine

And compared to my 16"

 

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Paz

Paz

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If I recall correctly the reason they need extension tubes for visual is so that they can be used for photography which needs more in focus.

The mirror cage allows you to walk the mirror up and down on the springs quite a bit and it has two mounting heights for the mirror cage onto the tube (at lest mine does) so there is some adjustability after you have received it. There is also then the option of extension tubes and hanging things a bit out of the focuser.

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guillaume320

guillaume320

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Thank you all for all the replies so far...

 

I'm not sure if they are the lightest dobs, but another reason for me to chose that one is that I don't feel like setting up a truss system.  As far as I see, the OO VX12 is much more a 'grab and go', and I think this might be a critical factor in not losing my enthusiasm at an early stage...

 

To Moonshane: So if I understand correctly, I do not need and extension after all?  Sorry things don't look very clear to me because I never had a Paracorr or the said focuser in hand, so it all sounds very theoretical to me...  Basically you are not sticking the Paracorr completely in the focusser? And this works for all your eyepieces?  Is this correct?  

 

Once again thank you all for your valuable feedback!


G

 

 

 

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guillaume320

guillaume320

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The Orion Optics website says this about their ACU-2S focuser:  "Incorporated is an extendable top section which allows the focuser to be used without the addition of extension tubes in nearly all applications"... So all should be fine?

Has anybody got experience with this focuser in general and if this is a 'quality item', or something I will be looking at replacing very quickly? And if so, what would be the best alternative?

G

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scarp15

scarp15

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The focuser provided as standard by OOUK on their current VX line-up is of a good quality and ought not need upgrading. With my VX14, when the paracorr is installed (though this is with a baader steeltrack similar in spec to the ACU) and as Moonshane has clearly already stated, I am able to use my full extent of eyepiece focal lengths and achieve focus. The paracorr has a long barrel for sliding back and forward enabling ease of focus, and the paracorr settings are easy to adjust. When I do not use a paracorr, I combine a 2" extension tube or no extension tube depending on the eyepiece requirement. This also applies to my VX8L which at F6 does not require a paracorr (I use a 1.5" extension tube), when this is too much, I sometimes might use a barrel extender on this scope, such as with my 21 Ethos. So at least in my experience, with a parracorr in place expect no requirements other than adjusting the barrel. Without is not too inconvenient but can become a bit more of a faff depending on the extent of focal length changes. 

For the aperture they are light and compact. I can handle my VX14 dobsonian without issue taking it to dark sky locations, my 8" is micro light and firmly a grab and go. As you point out, it is quick to set up and quick to return back to the vehicle. Collimation is often solid and accurate which I check before a journey, if dark when I set up I don't bother checking, knowing that it will be OK. There are differing opinions but Hilux coatings just maybe do give a little bit more in terms of brightness.  

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guillaume320

guillaume320

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OO is selling their ACU-2S focuser separately for £255, but then I could get the Baader Diamond Steeltrack for €304, which is roughly the same... I think it might be worth going the 'customised' way, no?  Sounds like a 'free' upgrade or am I missing something?

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scarp15

scarp15

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An alternate suggestion and often regarded on here, would be for a Skywatcher 12" Flextube. Heavier yet ergonomically it is very good for handling (I could carry mine up and down a flight of stairs), such as in and out of a vehicle and really is designed for dark sky travel. They are easy to set up and use in the field and the mirrors are a very good standard. They do require mods and an upgrade focuser is often a priority. The popular and straight forward choice is for a Moonlite CR2 or CR1 50mm travel. They come with an installation kit (purchased separately) that can be built up and assist with back focus. When I used one a few years back, I installed a CR1 single speed which was excellent, the best I have ever used perhaps o n par with a feathertouch on a former C8. I also used a 1.5" Moonlite extension tube and this accommodated my full range of eyepieces used at the time from low power 35mm up.  So just another consideration, include a shroud and be preferred to change the secondary collimation bolts and springs for primary. Will also be considerably cheaper even with a Moonlite installed, so giving some wriggle room for eyepiece budget and a paracorr is not really necessary so another big saving. 

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guillaume320

guillaume320

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Hi Brown Dwarf,

 

Actually, the Skywatcher 12" Flextube was initially one of the top contenders on my list... But reading about the weight and the rather bulky base, I was really forced to start considering the 10".  But inside myself, I have a feeling the 10" will leave me longing for more.  That's when I seriously started looking at reviews of the OO VX12.  The Skywatcher path is indeed much, much cheaper.  But I'm worried I might end up not using the SW 12", or will want to upgrade from a 10" very quickly.  

I estimate the OO VX12 with the new focuser, Paracorr, a Powermate and 3 TV lenses will set me back just under £3300.  But for the moment, I'm under the impression this equipment could last me a lifetime?

I haven't pulled the trigger yet... :)

 

Guillaume

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guillaume320

guillaume320

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27 minutes ago, Joseki said:

Im suprised noone has questioned whether getting a 12" f4 scope is a good first scope - a 8" f6 dob costs peanuts and is easy on the eps and will show you plenty and could save you a lot of cash.

A very valid question indeed... Would there be any reason not to get this 12"f4 scope in my case?  Are they difficult to work with??  I'm in a fortunate position that money is not the main concern.  If I can, I would just buy one scope and not outgrow it for a very long time.

 

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Moonshane

Moonshane

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my second proper scope was a 12" f5.3 OOUK dob and this was about 6 months or so after I bought my first (a 120mm f8.3 frac).

I'd have no issues recommending a 12" f4 scope as a first (and potentially last) scope. My scope numbers really only started to increase markedly when I got into solar.

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jetstream

jetstream

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4 hours ago, guillaume320 said:

Hi Gerry,

I would be grateful if you could expand a bit... Just curious ;)

 

G

Hi Guillaume, there are a few things. I have cold winter temps and this focuser barely works then. I don't like the sliding draw tube extension and I don't like the supplied 1.25" adapter, it can scratch EP barrels. The inside of the focuser drawtube slide is shiny, not good for controlling the stray light, I painted the inside flat black.

There are much better focusers out there in my humblest of opinions.

How dark are your skies?

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guillaume320

guillaume320

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33 minutes ago, jetstream said:

Hi Guillaume, there are a few things. I have cold winter temps and this focuser barely works then. I don't like the sliding draw tube extension and I don't like the supplied 1.25" adapter, it can scratch EP barrels. The inside of the focuser drawtube slide is shiny, not good for controlling the stray light, I painted the inside flat black.

There are much better focusers out there in my humblest of opinions.

How dark are your skies?

I'm moving to Koksijde in Belgium soon and the skies are not the best along the coastline (red on the map), but fortunately I'm only a very short drive to a 'yellow' rural area 

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jetstream

jetstream

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59 minutes ago, guillaume320 said:

Would there be any reason not to get this 12"f4 scope in my case?  Are they difficult to work with??

I'm sure the f4 scope can work well, the coma free area (sweet spot) of the primary will be small and accurate collimation will be needed. Coma will be a real issue @ f4. If size is not an issue the 12" f5.3 (VX12L) may not need a CC and has a bit extra focal length that can give a little more image scale, which can be a real benefit. In any event a quality set of collimation tools is nice and I prefer a sight tube (sec) and (cheshire or a barlowed laser for the primary). Just my thoughts.

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