Scale of 12" dob...

[emadmoussa]

Mmm...I see.

[SnakeyJ]

Imad,

Worth noting that the orion optics dobs have a lighter and more compact mount. Optically they are also favourably reviewed in comparison with the Skywatcher and GSO equivalents.

Generally the flextubes are heavier than solid tubes, but more compact for storage and can be split down for moving.

Jake

[nicks90]

edited: beaten to the post...

Edited September 23, 2013 by nicks90

[AlexB67]

Imad,

Worth noting that the orion optics dobs have a lighter and more compact mount. Optically they are also favourably reviewed in comparison with the Skywatcher and GSO equivalents.

Generally the flextubes are heavier than solid tubes, but more compact for storage and can be split down for moving.

Jake

I thought that the standard Dobs in sky watcher and Orion had the same optics no ?  I did see some sites offering Orion models to upgrade the mirror IIRC form 1/4 to 1/6 1/8 PV etc. of course it would cost extra so you get what you pay for in both cases ?

[emadmoussa]

I think if I'm decided on a dob I'll go for a 10", i don't think 12" will show dramatic change in views. Let alone the weight...

[mitchelln]

Here is my Skywatcher 300P Flextube both collapsed and extended alongside the newly established scale unit of 1 ReadyBrek The shelves behind are 6 foot high.

The two parts are just luggable individually. Each part weighs around 22 kilos.  I've found it holds it's collimation surprisingly well after being collapsed.

[foundaplanet]

I thought that the standard Dobs in sky watcher and Orion had the same optics no ?  I did see some sites offering Orion models to upgrade the mirror IIRC form 1/4 to 1/6 1/8 PV etc. of course it would cost extra so you get what you pay for in both cases ?

The reference to Orion scopes is that of Orion Optics UK a completely different company to Orion Telescopes USA with optics in a completely different league.

Edited September 23, 2013 by foundaplanet

[AlexB67]

The reference to Orion scopes is that of Orion Optics UK a completely different company to Orion Telescopes USA with optics in a completely different league.

Ah thank you for clearing that up So the ones they sell in the UK I mean were the ones I was referring to, they are the same optically as the sky-watchers ( they cost much the same ) ?

[foundaplanet]

Ah thank you for clearing that up So the ones they sell in the UK I mean were the ones I was referring to, they are the same optically as the sky-watchers ( they cost much the same ) ?

I don't think I am qualified to answer that question. I would however imagine that they will be Chinese made mirrors and much of the same quality wise as both of them do have good reputations.

[starwonder]

Hi, I know I'm new here but I have spent virtually all summer trying to contemplate the right first scope to buy.  After looking through a friends Orion Optics (UK) 8" 1/10 PV Dob and being utterly amazed at the clarity of the images of the moon and Saturn I have researched this manufacturer and according to their website they actually manufacture there own mirrors in the UK, they don't appear to import them from China: http://www.orionoptics.co.uk/OPTICS/opticsinformatio.html

[crashtestdummy]

from my time(best part of a year) with a 12" flextube I would say that's it pretty portable for people of average build as im 5'7" and 11 stone.the main tube is a good 20kg(maybe a bit more) so its not exactly featherweight and the base is a similar weight but I personally don't class either as unportable although the base wont stand up in most low booted cars it fits nicely on its side.a friend manages to get the whole thing in the boot of a mk4 golf.

the flextube is a fair bit heavier than the solid tube as there's much more metal there

the orion optics 1/10 should be better than the skywatcher mirror,its 3 times the price!!!!!!!

I personally would either get the 8" or the 12",the 10" is too much of an imbetween and the skywatcher 250 is hard on cheap eyepieces.

Edited September 23, 2013 by crashtestdummy

[AlexB67]

interesting view, not what I want to hear , saying that the 12 inch is f/4.9, the 10 inch f/4.7, not that much diff with the distortion you get, not exactly a hard line I would say, but the 8 inch it becomes somewhat more appealing at f/5.9.

Edited September 23, 2013 by AlexB67

[John]

Orion Optics are wholly made in the UK.

Orion (USA) dobs are made by Synta in China who own and make Skywatcher scopes and Celestron scopes, amongst others.

Orion Optics scopes are much more expensive to buy new than their chinese made equivalents but offer a range of focal lengths, tube and mirror specifications. They are quite reasonable to buy on the used market though and thats how I bought the OO scopes that I've owned including my current 12" F/5.3

[AlexB67]

Orion Optics are wholly made in the UK.

Orion (USA) dobs are made by Synta in China who own and make Skywatcher scopes and Celestron scopes, amongst others.

Orion Optics scopes are much more expensive to buy new than their chinese made equivalents but offer a range of focal lengths, tube and mirror specifications. They are quite reasonable to buy on the used market though and thats how I bought the OO scopes that I've owned including my current 12" F/5.3

You lucky man ,  I saw one of those on ebay time ago, did not have the cash or could have bought it at the time ( it was a 10 inch though ) , but it was sold in no time, only afterwards did I realise what it actually was in terms of optical quality as I learned about mirror specs etc. Now I got the cash I could have bought  it, of course they are nowhere to be found. I could press the buy it now button at FLO if I wanted to buy the 10 inch sky-liner, but gonna keep my eyes open, no rush, you never know what may turn up in the next month or more for that matter.

Edited September 23, 2013 by AlexB67

[SnakeyJ]

Just seen an interesting post from John in another SGL thread:

Heres a company that does scope hire:

http://www.darkskytelescopehire.co.uk/

I don't know how much business they do though 

This business hires dobs between 6 & 12" - so this could be a really good way of trying before making that final buying decision.    They also happen to have a 12" Orion Optics dob, which looks very tempting to me.

[starwonder]

Fancied the idea of hiring a scope myself to test the water as it were and although a good idea it's restricted to south of UK :-(

[LukeSkywatcher]

Aha, that doesn't look that big.

Famous last words.

[emadmoussa]

Famous last words.

Really isn't huge, but still hesitant about the weight though..

[mitchelln]

Let me know if you want any more pictures of my 300P. I could show how it fits in my car, for example.

Sent from my GT-N7105 using Tapatalk 4

[LukeSkywatcher]

Really isn't huge, but still hesitant about the weight though..

Visit a shop and get up close and personal with one and that will let you know.

[crashtestdummy]

the difference between f4.9 and f4.7 could be the difference between no coma and lots of coma though.ive never really heard any bad reports of the 12" on eyepieces but lots of the 4.7 so its make your own mind up time

[AlexB67]

the difference between f4.9 and f4.7 could be the difference between no coma and lots of coma though.ive never really heard any bad reports of the 12" on eyepieces but lots of the 4.7 so its make your own mind up time

Could it is just the eyepieces some use. If you can afford a big 12 inch you may also have better eyepieces in you arsenal ? Lots of reasons perhaps why such reports may be coming from various sources. I don't ever really recall ever reading that in this forum anyway or some others that I read ( but not registered user).

In the end of the day Coma goes as f ratio^3, there is no hard line but it does grows as the cube ( or the square  depending linear or angular version). Not that I've looked through either mind you except my own at f/5. Not trying to bicker or sound hard headed , but trying to rationalise it. In the end of the day both such systems would actually have a very small field where the coma lies within the diffraction limited field anyway ( I've done the sums on it and can create a few tables if you like).   

Granted, I do not have the experience of the big scopes that you own, that being said, the numbers don't lie, without trying to sound too much like a Mr Gradgrind :0) I find it a bit hard to follow your rationale. Perhaps there is more to it as to why you say that.  I am all ears, or tell me if I am just being pest and being difficult and I'll go away    

Ideally I'd like my 10 inch Newt to be at least f/5 or above really, ( f/6+ inch dreams I have )  but when I think 4.7 or a 4.9 as a hard line it would not stop me buying either way, coma is what it is in Newts, there is always a coma corrector I can think about down the line anyway, not that coma bugs me a lot of the time anyway once I am out there looking up the sky, sure enough,  I do see it in my scope, it is there.

edit: I should have said that my argument assumes a parabolic mirror shape. All of these sky-watcher are afaik, except some of the lower end smaller ones where it may be spherical in which the f ratio cube relationship is not true and the other aberration  rules not even mentioned ( but do exist)  if I recall my formulae correctly without a check .

Edited September 25, 2013 by AlexB67

[Moonshane]

my view has changed on coma recently and also cheap eyepieces in fast scopes having tried it for myself. sure Televue are generally better but if you are on a tight budget and want a fast scope for convenience or field then you can get away without using a coma corrector. again, it's better with a coma corrector but neither the world (nor your enjoyment of astronomy) ends if you don't have all three of these elements.

http://stargazerslounge.com/topic/166265-cheap-vs-expensive/?p=2051065

[Naemeth]

my view has changed on coma recently and also cheap eyepieces in fast scopes having tried it for myself. sure Televue are generally better but if you are on a tight budget and want a fast scope for convenience or field then you can get away without using a coma corrector. again, it's better with a coma corrector but neither the world (nor your enjoyment of astronomy) ends if you don't have all three of these elements.

http://stargazerslounge.com/topic/166265-cheap-vs-expensive/?p=2051065

Indeed, cheap eyepieces are better than no eyepieces .

Whilst I haven't tried a Paracorr yet, the coma on my 10" dob doesn't seem that bad, and it's F/4.7

[emadmoussa]

Dumb dob question here, what's this Paracorr I keep hearing about?