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Daniel-K

SW 18" dob review

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50kg!thats a bit heavy and it does like there sticking with the small counter weights on the back of the cell. id have thought that 130mm for the secondary was a bit to big.

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Very interesting.. Would like to see one in the flesh...wonder if one will be on show at the Hertsy festival?

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An interestjng write up but id agree that 50kg seems heavy for such an ultralight design although they will be made to a price so trimming weight may have been difficult.

The chap seems to have his sums wrong as at f4 this should have a 1820 focal length so im suprised to see he couldnt reach the eyepece at the zenith , especially as he saysnhe is 6ft 2 so maybe the mirror is more f4.2 or the base is really high for some reason.

Its good to see these big dobs being taken on by mainstram manufacturers as this may help move forward some design elements and as an ultralight design they are obviously trying to up their game.

Cheers

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looks a lovely design weight isnt that bad and then consider the price i think there on a winner here

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looks a lovely design weight isnt that bad and then consider the price i think there on a winner here

Am I being blind; what is the expected price?

It can only be a good thing that mainstream manufacturers are now looking at 18" and 20" scopes. Just imagine the quality and value for money that these things will get to in a decade or two!

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Apart from being a good pic, what is this image saying? an 18" dob is the instruement you want for widefield views of the milky way?

post-20406-0-44563300-1409949822.jpg

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Apart from being a good pic, what is this image saying? an 18" dob is the instruement you want for widefield views of the milky way?

That picture caught my eye too, cracking dark sky though!

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Apart from being a good pic, what is this image saying? an 18" dob is the instruement you want for widefield views of the milky way?

I think it's supposed to show, what the Americans call, a target rich environment  :grin: Will be interesting to see what UK price is. Conversion from Australian $ is around £3K . 

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£3k would be expensive in my eyes as a Nichol optical f4 18inch is about £ 2.5k for the mirror and would be better quality than a mass produced skywatcher ..... and with 16inch revalations being just £1300 it would be hard to charge another £1700 for an additional 25% more glass.

Cheers

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i think they need to be £2k to stand any chance of selling any.i was hoping they where going to be released in july of this year as per the rumors but nothing came about so ive ordered the 16" Alkaid Sumerian which is extremely compact. I thought they would have thought up of a new fancy focuser to stick on a new product like this but they've stuck to there standard duel speed which I think is a let down.

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Id agree, a decent moonlight cr2 would have been better and as they would be buyin in bulk wouldnt have broke the bank for them. Maybe this is one of the things they had to cut back on to keep on top of the price and still make a profit.

Im liking the increase in big dobs though, its a visual observers dream that these are even been considered by maintream manufacturers. The base also seems to have an asymetric side bearing to swing the weight backwards at low altitudes so I wonder why the counterweights are still needed.

Cheers

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A little bit of a tease really that there is currently no indication as to when this model will retail in the UK. That is unless there are still some small ongoing modifications that might take into account feedback reports from initial markets such as Australia. Perhaps they expect the floodgates to open with orders when it does hit the UK. Certainly anyone who has had a flextube and understands first hand the reliable quality of the mirrors, decent build based upon the value, and the dependable functionality of these models could be contenders to consider getting their hands on what could be a potentially affordable large aperture and highly portable system. I guess where the focuser is concerned, anyone interested in purchasing this would I expect be upgrading from a smaller aperture model and so may well have already upgraded their focuser thus transfer it onto this.

Investing in a high quality mirror is a very attractive option, however unless someone you know can offer support in the build, many I would expect (including myself) would like to attempt, yet do not have the workshop and facilities, tools, time and expertise to embark with such a project. 

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Great kit review, but I would have liked some information on how the mirrors performed with DSOs and planets. Might be the most important part of any purchase decision.

Daniel, you made the right choice with the Sumerian; the weight of the 18" is roughly the same as my 400p, which is quite unwieldy.

I perservere, though; the views are worth it!!  :)

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I have a feeling this will perform as well as any other large aperture skywatcher, although whether an 18inch f4 can be made at a mass produced level will be a good test for skywatcher.

I hope on the uk release they have added some protection to that big mirror as like kirkster says i too would be nervous transporting such a big mirror with such an exposed edge. Another,one for me would be to give a bit more length and width to the focusser plate as id want to move the finder further down the scope and also fit an RDF ..... oh and skywatcher definately need to swap the straight through for a RACI , unless they only expect people with very long and flexible necks to use the scope !

Modifications aside, this does look the buisness though.

Cheers

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.... oh and skywatcher definately need to swap the straight through for a RACI , unless they only expect people with very long and flexible necks to use the scope !

Modifications aside, this does look the buisness though.

Cheers

I'm not so sure I agree with you on this point Ian.  :confused:

I would very much like to try  a straight through (correct image) finder on my 20"  as most of the time it would be easier to look up through it, I think. Obviously without trying one though I'm kinda guessing   :grin:

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Hi steve,

I tend to find a raci easier to use on a wide tube scope as to use the finder when at the eyepiece I cant lean around the top tube enough whilst looking up the tube at the same time, especially when the scope is at a 45 degree angle.

For me it might be because I have the focusser, then the rdf then the raci, so the finder is furthest away from me so the rigt angle helps loads.

Out of interest what finder do you use at the moment ?

Cheers

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There's probably more metal in my Skyliner? I`d be feared to use this scope as its so exposed to the elements. I'm sure I`d want to dust that mirror prior to every use,  and the cost will be prohibitive. I can't  imagine  that constructing the telescope everytime I wanted to use it  would be of any use, and a waste of my time. I think the maximum I would have is a 12" solid tube. The only reason I have to go larger  at present,  from my slightly light polluted garden, is to increase my image scale that the 8" provides. The 10" would offer some improvement, the 12" more apparent. I`m not sure I'd want to rid my BST collection , as this works very well on the present f/6  and for some folk, still works well on a 250P.  There's no doubt about it, once the 18" is setup, the views will be stunning from the perfect site, such is the difference that any  telescope offers from darker sites. But the lower f/ratio, EP consideration, weight and cost, will limit any further purchase I make.

Edited by Charic

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Hi steve,

I tend to find a raci easier to use on a wide tube scope as to use the finder when at the eyepiece I cant lean around the top tube enough whilst looking up the tube at the same time, especially when the scope is at a 45 degree angle.

For me it might be because I have the focusser, then the rdf then the raci, so the finder is furthest away from me so the rigt angle helps loads.

Out of interest what finder do you use at the moment ?

Cheers

I have a RACI finder plus a telrad, but I have them around the other way to you. I have focuser, RACI finder, then telrad  ;)

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Cant wait to see one of these in action at the next starparty.

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