if YOU had to choose

[sunshine185]

I currently have a sw 8" dob, and Need some buying advice. I have 3 options, buy a 250px for £450, get a flex tube goto 8" for about 850 I think, or keep the 200p and get something else? The current favourite is get a 250px, I believe it is much better than the 200p at resolving star clusters, but I am not so sure. Looking for the usual excellant sgl advice on what route to take.

[Mike Hawtin]

Depends on what you want to observe really. Deep sky, lunar & planetary? Do you need to travel to observe? What do you think you might be doing in the future, purely visual or maybe get into some sort of imaging. Can't really advise without knowing these things sunshine.

Mike H

[sunshine185]

Purely visual only, will never travel with the scope, only observe from the back garden. Lp is pretty bad here in Oldham, but have no direct lights visible from the garden. Mon and planets, gc's , galaxies etc so all-round observing is the aim.

[swamp thing]

For all round observing you probably have the best scope.

The 8" skyliner is a very capable all round scope.

A 10" will give you better views of DSO,s but the planets won't be much difference IMO. You may find your LP sky controls what you can see in the way of DSO,s more than the aperture though.

Also a 10" (because of their normal faster design) is harder on eyepieces.

[jonathan]

Then the advice is probably simple - get the biggest you can afford / lug out to your garden! The 8" Goto seems like a sideways move to me, you would be paying a lot just for Goto, you'll probably find that most of the objects in it's database are not visible from your light-polluted location.

[estwing]

goto..to me seems like "sneeking a calculator into an exam"..just learn the star hoppin' cheaper and rewarding!

[Mike Hawtin]

+1 for aperture, if you're not travelling it trumps everything else.

Mike H

[sunshine185]

That's what I am thinking Mike, but is there really much difference between 8" and 10" to make it a worthwhile upgrade? The 300p is out of the question, 10" is as much as I could handle and store.

[Mike Hawtin]

Personally I would say yes it is worthwhile, ok so some might say it is "just" 2 inches more but that 2 inches is a 25% jump over your existing scope, and that extra 2 inches also gives you 56% more light gathering area, I'd go for it!

Mike H

[sunshine185]

Hope the ppi claim goes through, then gonna slap an order in, my minds made up

[estwing]

it's not about the size,more about the skies..you'd be amazed what "happens" in proper dark skies.

[sunshine185]

That's one thing I am not gonna get,I don't have transport so the back garden is it as far as observing sites go. I have an awful feeling that if I went somewhere that had truly dark skies, then I would be so disillusioned with viewing from home that I would give up astronomy altogether. Home observing is all there is gonna be for me

[estwing]

shame, swamp thing says he doesn't bother viewing too much at home because once you've been to a darksky spot..it's a let down "home viewing". couldn't you get a mate to take you and get him/her interested? = cheap taxi!!

[Phil Fargaze]

I am located in a London suburb and I was using an 8" dob for general observing on most types of objects . When I got the 10" dob it was a pleasant surprise to see the difference the extra aperture made. I really enjoyed getting out there to see what else I could discover and to revisit objects I was familiar with.

[sunshine185]

Phil, that was the reply I was looking for, I read lots of posts saying going from 8 to 10 isn't worthwhile, but you have actually done it and have seen a noticeable improvement. I can imagine getting out to somewhere dark, then when back home and realising how bad it was I would probably think to myself, "what's the point" and sell up. I am a firm believer in the old saying - you don't miss what you never had.

[ollypenrice]

Our 20 inch Dob was made buy an Oldham amateur, Dennis Mien. Nice guy, good scope! Irrelevant post but nice to think aboput Oldham!!

Olly

[Theninjagecko]

Keep the 8 for a wider view, Get a 12" Dob to really get in there.

[newman]

I wouldn't get a 10" if I already had an 8" - it's not that huge of a difference. Sure, the 250mm will outperform the 200mm one, but it would make more sense to me to save a bit and get the 12" or even bigger - especially since portability isn't an issue in your case.

[stevetynant]

I agree with newman - although I have no practical experience of this jump personally, everything I have read tells me that there is no wow factor jump from an 8 inch to a 10 inch Newt. It will be better but considering the cost involved is it worth the extra expense? Having said that Phil has practical experience of the jump so definitely worth considering and only you know whether it justifies the additional cost..

Personally the next move I make will be from the 200p to a 350p if and when I can afford it - that should be a noticeable increase in viewing hopefully.

Good luck with your decision making anyway.

Steve

[Moonshane]

the OP suggested the 10" was the biggest they could store and carry so I'd suggest this is very worthwhile. some of the comments about 8-10" not being worth it relate to assumptions you will eventually go larger to e.g. a 12" and if that's the case it's possibly not a good idea.

are you going to sell your existing scope? I'd wager there would be a good used market for an 8" dob and this might provide some cash for eyepieces, a telrad etc.

I don't know if you have ever seen a 12" dob but although they are big, they are certainly moveable by one person, especially if you bought a sack truck / golf trolley etc. a 12" scope makes a big difference to an 8".

I observe from a light polluted area too and can see lots on the better nights from home. I had a 12" but moved to a 16" and never regretted it!

[newman]

I was sort of going with an assumption that if he can store a 10", he can probably make room for a 12" flextube - if that is not the case and the 10" is the absolute maximum in size, then it's really a no brainer. But in the OP's shoes I'd do a lot of measuring before making that determination

[Moonshane]

I was sort of going with an assumption that if he can store a 10", he can probably make room for a 12" flextube - if that is not the case and the 10" is the absolute maximum in size, then it's really a no brainer. But in the OP's shoes I'd do a lot of measuring before making that determination

I totally agree with your logic - and applied it myself. in reality the base is often the main issue with Skywatcher scopes in that the base of the 12" has a larger diameter then my home made 16"

[sunshine185]

the measuring has been done, it will be stored under the stairs and a 300p wouldnt fit unless i removed the stairs! i am not looking for a huge increase in resolving power, its just that a few things i see i would like to see a little better, i also believe i would get a little increase in fov in the 250px compared to the 200???, which would be welcome if true. i already have the wow factor with the 200, so it would still be wow with the 250. if the claim comes through then i want to get a scope ordered before the missus orders 40 pairs of shoes, so just needed a little advice, which once again has proved invaluable will get the 250, and with the cash saved on not getting a goto, i can get some other bits and bobs, a couple of extra ep`s for the bv would be nice, hell i could even get a 28mm nirvana with the cash saved. thnx again fellow stargazers.

[Moonshane]

the focal length of the 200 is 1200mm and the 250 is (I am pretty sure) 1250mm so the field will be very slightly less in the 10" (although you'll not really notice it for most targets.

e.g. for a 25mm plossl with a 50 degree field of view, the actual field visible will be approx. 1.04 degrees in the 200 and 1 degree in the 250.

extra aperture will always make the view better for most targets in my opinion. things like globulars and relatively tight open clusters also look superb with more background stars.

I doubt you'll regret it.

[Mike Hawtin]

I observe from a light polluted area too and can see lots on the better nights from home. I had a 12" but moved to a 16" and never regretted it!

Take note sunshine, that is a 33% increase in diameter not too different to the 25% jump from 8" to 10" diameter.

Mike H