Skywatcher Dobsonian Scope - how big to go?

[Polynikes]

Hi

I’ve been perusing these fantastic forums for a few weeks now as I look to purchase my first ever (proper) scope. I’ve currently got a Celestron C70 mini-Mak spotter scope to just view the moon and learn the constellations and way around the sky – who knew the saucepan was actually part of a much larger constellation. :icon_salut:Nice and portable it is too, although I desperately need a cheap camera tripod for it.

From the other topics, it seems that the Skywatcher Dobsonian is a favourite for n00bs, so will likely be my first choice.

Now it’s just a question of how big to go. I think my interest will mainly be in DSO’s and as I understand it bigger, well wider, is better for viewing these things? I can feel aperture fever rearing its ugly head already as I look on FLO’s website – ‘for xxx pounds more I can get another 2 inches’.

I live in the centre of Reading in a 1st floor apartment so will have to travel out of town for all my viewing sessions (no idea where yet). That leaves me having to balance aperture with cost, transportability (both in lifting and fitting in my Focus) and to a lesser extent storage.

So 200/8” seems to be a good balance and the one most opt for, but I’m wondering if it’s worth going for 10” or even 12”. Will they offer significantly better viewing of DSO’s from a darkish site? Enough to make the hassle of carrying it about worthwhile (I’m 6’5” so the carrying down to my car will likely be achievable – god forbid I pull my back out in the middle of nowhere though).

Would flexi-tubes help with portability or are their benefits more storage?

I fear I'll be like I was when I got my 42" plasma after umming and arring for weeks - then quickly thinking - should have gone for 50".

Whilst I continue to deliberate I have ordered what seems to be the SGL bible though; Turn Left at Orion.

Your thoughts would be welcome.

PS - My next order of business will be to pop in and see the local Astro Society who I believe have a meeting this Saturday and annoy them with questions.

[kniclander]

flex tubes don't help with portability unless you can't fit the solid tube in your car. generally, the flex tubes are heavier than the solid tubes and obviously you will ahve to set them up at the site (and probably collimate too). The non-goto dobs are very easy to move in two parts, ie ota and base - they take just a few seconds to take apart and put back together. The 10" ota is pretty light but the 10" ota plus base is certainly at the limits of my abilities to carry around. I suspect the 12" ota on its own would be fairly easily manageable but the 12" ota plus base would be too much to carry.

you should therefore get the............. 16".....

[david o]

I think the best thing will be to actually see one in the "flesh", as it were, and try it out for lifting/carrying/transportability Maybe you'll get a chance at your local Astro Soc.

The flex-tube type Dobs will be easier to transport, but the downside is that they cost more per inch of aperture than a standard, solid tube Dob.

Oh... and welcome to SGL

[ZEbbEDY]

As big as youcan afford

[Polynikes]

flex tubes don't help with portability unless you can't fit the solid tube in your car. generally, the flex tubes are heavier than the solid tubes and obviously you will ahve to set them up at the site (and probably collimate too). The non-goto dobs are very easy to move in two parts, ie ota and base - they take just a few seconds to take apart and put back together. The 10" ota is pretty light but the 10" ota plus base is certainly at the limits of my abilities to carry around. I suspect the 12" ota on its own would be fairly easily manageable but the 12" ota plus base would be too much to carry.

you should therefore get the............. 16".....

I like your style

I'd definatley only be transporting it whilst in 2 pieces.

[Pete Presland]

another vote for the 16" wow that should keep apeture fever on hold for a while!

[NGC 1502]

It's really tough to give advice. What is big & heavy to one person will be no problem

to another. But you definitely see more with increasing aperture, no question. But it

is a subtle change from an 8" to a 10" or 10" to 12". 8" to 12" is a more definite change.

I settled (eventually) on 10" as I have to carry my scope up & down a flight

of stairs. The solid tube fits in my Fiesta ok, so it's right for me.

The Flextubes may be a bit heavier, but fit more easily in a car, so that could sway

your decision to go larger perhaps.

But if you are 6' 5" and hopefully fit, I'd say 10" maybe larger. Try to see one in the

flesh if you can.

Good luck, Ed.

[Mark at Beaufort]

I would recommend that you don't rush and make a quick decision on your next scope. Yes the bigger Dob will show you more detail on DSOs but you must think about carrying this scope downstairs and into a car and then travelling to a suitable site.

There are so many people that have bought big scopes only to leave them in the back of the garage/shed because its too much hassle to take it out especially if you have been working all day.

I have a 10" Flextube Dob in my garage which I take apart to move down the end of the garden 25 metres away. If the sky suddenly clears sometimes I just grab my 4" frac or 6" Newt because it is easier.

At the recent SGL6 star party I used a Skywatcher 6" Newt and starhopped to about 20+ DSOs including the Whale and Hockey Stick so you don't need a big scope to enjoy this hobby.

Having regard to your circumstances I would buy an 8" solid tube Dob and buy a few better EPs. This will allow to access your circumstances of storage, transporting etc.

If you look after this scope and you want to eventually buy a bigger scope you will be able to sell your 8" on this forum (providing you have 50 posts).

Best of luck with your decision.

Mark

[Beulah]

DO bear in mind that because of your circumstances, portability rules over aperture. If you purchase an 8" and take it to a dark site, it will let you see a darnsight more than if you set up with the same scope (or even with a larger aperture) in the light polluted area around your flat.

Let us know what you decide. When or if you ever move to a house, then increase the aperture!!!

[banner001]

a 10" solid tube should fit in any car with a few inches to spare...a 12" is usually a little too long to fit across the padded rear seats (optimal place) and you will therefore need to place it elsewhere.

if you are going for the 10" get the solid tube, >12" get a flextube.

IIRC orion optics uk do a 14" solid tube, but thats the biggest i think you can get, ive not seen a 16" solid tube, they are all truss types to save on weight.

[JamesM]

There should be no rush when it comes to buying equipment - the stars aren't going anywhere. Personally I would buy the biggest scope you can drag out into your car because for me, the end justifies the means. But seriously, you must take some time out first to go and look through and also at some of this kit to judge if what you see will meet your expectations. Financially it makes sense (funds permitting) to buy once and get it over and done with as this will be the cheapest route in the longer term. Nothing worse with dabbling around buying and then reselling till you achieve your final goal. I have looked through plenty of 12" dobsonians including Meade Lightbridge, Skywatcher, Revelation and in particular Orion Optics UK who are the only company that allow you to specify the quality of some of its components - at a price! That size of aperture is really good and for me, if a compromise was sought between mobility and views, would tick the box. There is no such thing as a beginner scope, only one that works and you will be the best judge of what you can afford and the logistics of getting it out to a dark site.

Clear skies

James

[Capricorn]

Go look at one first.

16" is probably too much to carry up and down stairs in a flat. I would guess that it would end up not getting much use.

I would give odds that you would "see" more with a 150PL then a 16". Simply because you would use it a lot more and so see more.

Remember also that being 16" the scope will have to be fast, probably f/4, so could need collimating everytime you bounce it round getting from flat to viewing site. It will also be critical of collimating and need it very regular.

Just be aware that there are disadvantages to a big scope, and you may not get told all of them nor be aware of all of them.

Have you used a dob before?

[johninderby]

Trust me, you don't want to be carrying a 16" solid tube dob up and down stairs on a regular basis, it would really be a two man job. BTW OO does a 16" solid tube dob.

10" is a nice medium size. The OTA is easy to carry for most people so it would be two trips to get it downstairs, one for the OTA and another trip for the base. It's what I'd recommend if you could have only one dob.

I have a 150PL on a Skytee 2 Alt-Az mount, a brilliant combination, and it gets used on a regular basis as it is so easy to move and set-up. However I should mention that it's been heavily modded with 1/12PV OO optics, new focuser, CNC mirror cell etc.

I also have a 14" OO dob that I use when seeing is very good, and I consider it to be the largest "easy to move" dob as it only weighs about the same as a Skywatcher 12" dob.

John

[bish]

I was unsure between the 10" and 12" solid tube. In 2 parts the weight isn't a problem. I'm an average 5'10" forty year old and the 10" is ok to move around. I would think that at 6"5 the 12" tube wouldn't seem too bad. The thing that swayed it for me is the dimensions. A 10" tube fits across my car's back seat, with the base in the back. This means that I can easily take to a dark site. I chose to have a 10" that i can take to a dark site over a 12" that might just stay in my light polluted back garden.

[Moonshane]

Personally, I have always taken the view that you should look to increase your aperture by 4" every time you increase to get the wow factor. so 8"-12" and 12"-16" and 16"-20" etc.

given your circumstances and willingness to travel to a darker site, I''d actually suggest an 8" dob at the current time. you don't mention budget but think about some eyepieces etc although these will of course remain with you through other scope purchases.

the 8" SW dob base is surprisingly large in diameter (bigger than my old OOUK 12" dob base in fact) so will take up a lot of space in the car and house.

try and buy a used one if you can to get the feel of it and then you will not lose too much if you upgrade in a shortish time.

you may eventually decide to upgrade to a 12" which are far more common than 14" which would be the logical step (in my view) from 10".

the size of scopes increases exponentially. See the tube in the attached photo which is a 16" f4 tube compared with a f5 6" tube. also, my old 12" compared with my 6" f11 which is a longer tube but the same diameter as the black 6"; there's a bigger difference in tube size than is suggested by the 4" increase in diameter of the mirror. This is as large as I'd go in a fixed tube and this will just go in my Rover 200 hatchback with the rear seats down. ironically, a 20" truss tube would take less space in the car!

even this beast will have a base floor area of only 22" square. not sure but I suspect the diameter of the 16" SW base must be about 8-10" more than this?

I feel a good start would be an 8" as this from a dark site would should a dramatic number of objects if you are relatively new to the hobby (and even if not!). It's an excellent all rounder without breaking your back or your bank.

BUT if you are sure you are hooked, you are quite right that aperture is the best thing for DSOs and a 12" would be a wonderful instrument. If you can afford one that tracks (not goto) then even better.

[Moonshane]

ps collimation is a synch after a few goes and is nothing to worry about. you need to learn how to do it. full stop. it's honestly no reason to be worried or avoid buying the aperture you seem to crave.

[swamp thing]

Hi

As a 16" scope owner I can tell you they are pretty bulky scopes.

You'll need a pretty big apartment for it to blend in to the background.

I store mine upstairs, and lifting it up and down them I don't find a problem, but I did body building for many years.

I would strongly recommend you go and see one and how you find lifting it.

I transport mine every time I use it in a van so cannot help on what size car you'll need.

The big 16" mirror is heavy so requires collimating every time it's used (this is very easy but you should be aware it must be done every time you transport a scope this size).

Also they are not grab n go scopes, so for quick sessions you'll want something else.

I spend a lot of time going to dark skies with mine. Else I wouldn't bother with such a big scope.

I have owned mine for Three years and still love it in fact my next scope will be even bigger.

If you are prepared to travel to dark skies be prepared to be blown away by the views. IMO nothing comes close to visual observing with a large aperture scope.

Regards Steve

[Polynikes]

Thanks for the comments everyone.

Just to clarify - I have no intention of getting a 16" Dob whilst living in an flat.

In my head, I'd kind of settled on a 10" as a starting point and I think that's been reaffirmed by comments here.

I doubt I would look to upgrade it to a bigger Dob anyime soon anyway, unless I had my own garden at a dark site. It could well be that any additional scope is a start into the intriguing world of astrophotography.

And one final point, I certainly am in no rush to buy a scope, and will definately be wanting to see them in the flesh first. I believe the Reading AS have one, so hopefully I can get a look through that at some point.

[M4lcs67]

I bought an Orion XT8 a couple of months ago and being a newbie I didn't really have a concept of the sheer size of the thing until it arrived. Once set up in my living room I realised that I had dropped a clangar as the thing was huge and I could not live with it on a day to day basis, so I sent it back. I don't doubt that it would have given some stunning images, but I have a very small house which could not accomodate a telescope of that size. I now have my Celestron Nexstar 127 Mak and that is much more compact. Blimey even the wife is happy now due to the fact that I am not cluttering up the house with a "rocket launcher".

[callisto]

10" all the way

[Crunchard]

Just got my 10" auto, and very nice it is. Good build quality, easy constructions, fairly easy to handle (if you check out my other posts you will see).

Think the 12" would have been a touch too far for me (unless I suddenly get apperture fever) and the 8" would have been a touch too small.

Best thing is to go view some and see what you think you can handle.

[Patrick1948]

10" all the way

I moved from a Celestron C 6 N on a good mount to a SW 250px Dob...manual not go to or tracking. Like the quote from Callisto says "10" all the way. I'm in my 60's with numerous health probs, but transporting the dob from house to garden, or house to car is no problem at all...AND ... the views are fantastic. A 10" will last you for years. Clear skies to you and good luck with your choice.

[ScoobyStoo]

I'm in a very similar position (terrible local light pollution) and have decided that a 10" FlexTube hits the sweet spot. Packs down just small enough to go in the boot of the car along with a few bags for a weekend away.