Skywatcher dobs: 10" standard or 12" Flex ?????

[jonstarrysky]

Hello all,

I need to choose a scope to get me substantially greater deep sky power than my current 6" reflector in reasonably light polluted skies. I have panoptic & Pentax XW eyepieces. Main observing area is patio close to storage area with only very small step. But will want to relocate around garden sometimes to dodge trees, and take to dark sky sites.

My main choice is Skywatcher dob: 12" flextube vs. 10" non-flex.

I dont like the idea of collapsibles & trusses, and prefer the security & simplicity of closed tube, but for 12" and above it becomes a necessity when transporting.

10": I fear i will yearn for the power of the 12" (and encounter resistance from the other half if I want to later upgrade: "not another xxxxxx telescope"). My spare room will amply house the 12" and opens out directly to the patio.

12": I fear that even though able bodied and 6"2' the size of this moster will make observing a big effort. Lightpollution etc will to a small degree cancel out the extra apeture vs. 10". It costs double the price (but is still about the same cost of my existing eyepeices).

Any feedback from people who own or have used these models most welcome !!!

ALso does anyone have comments of general quality (eg smoothness of azimuth motion), focusser between the Skywatchers & Lightbridges ??? I dont like the idea of the trusses, but if the quality is oozing in abundance, then I'll reconsider.

Many thanks !!

[Ben Ritchie]

Hello Jon, welcome to SGL!

I have the solid tube 12" Skywatcher, and would certainly recommend it unless you regularly want to take it somewhere in a car - for moving around the garden it's not bad at all, I was worried that it would be huge and heavy but if you move the tube and base separately then it's not difficult (and I speak as a 5'11", 140lb weakling). The views are great, and I think 12" vs. 10" is worth the money. Given the price/performance i'd count it as one of my best purchases in astronomy.

For portability, round the garden is easy enough, and getting it into our medium-sized car is a bit of an effort, but possible. If you're regularly going out to dark skies then a truss dob would be the way to go, but if - like me - 95%+ of your observing is back-garden with only a handful of trips out a year then i'd think the simplicity of the solid-tube dob is worth the occasional struggle out elsewhere.

I upgraded the focuser on mine to a Moonlight, but the standard one isn't bad at all. Azimuth motion is fine, not quite an Obsession but respectable and easy to adjust.

[John]

My observing sutuation is similar to yours and I have recently bought a 12" Meade Lightbridge.

Getting it outside is a simple 2 part operation (too heavy to move in one piece !). I've not had the scope long but the build quality is OK and the motions very smooth. There are a number of things that need doing to the scope such as stronger collimation springs, a light shroud and some counterbaqlancing for heavier eyepieces.

Optically it performs well (although I've only had a couple of hours with it so far) but collimation does need a tweak each time you use it.

I need to work how to move the scope around the garden better - maybe some sort of dolly ???.

I've owned 8" and 10" Skywatcher dobs and the 12" is a much bigger scope to handle - I'm hoping that the lightgrasp will reward the effort when I get some decent viewing in with it.

John

[kniclander]

if the 12" flex is twice as much as the 10" solid, i would go for the 10 especially if your skies are LP'd. You will have ££ left over for e/ps. collimation stuff, focusser (but I find the standard skywatcher focusser fine), woolly sockes, thermals etc etc etc

also, whatever you get you will want something bigger....

[jonstarrysky]

Thanks for the replies so far !

Message to Kniclander: can you comment on the deep sky capability of your 250px vs. your 150p skywatchers. I have a 6" reflector which in theory will give light grasp like your 150p. I want a noticable difference in the number of fuzzies I can see and how bright they look. If you say the difference is noticable but not really a big deal, then the 12" might be the way to go. There is no doubting the 12" will show much more (4x the light grasp of 6"). The 10": well thats a closer call isnt it ?

The post from Ben Ritchie makes me consider the solid instead of truss in the 12" size. They actually weigh the same (ish). As long as the OTA can span the backseats of my Astra, then I'll be OK. I prefer the security & simplicity of solid tube.

[Ben Ritchie]

They're quite common 'scopes, so if you're in any doubt then it's worth finding your local astronomy society or star party and going to see one in action. That'll help make up your mind quite quickly.

Going up to 12" is well worth it as long as it fits in with your portability needs, I know what kniclander means about always wanting bigger but 12" isn't a bad compromise between ease of use and aperture ... there are times i'd love a 20" but equally I love the 60-second setup time with my solid-tube 12", it's just two quick lifts of the tube and base out from storage to the garden, and then a bit of cool-down while it gets dark out. It holds collimation very well. Any bigger and you're well into truss territory, and the instant convenience is gone.

[jonstarrysky]

Hi, transporting the 12" skywatchers as two parts as indicated eg: across the garden to dodge a tree to get a glimpse of Saturn. Isnt this a big pain ? Or can you just take off the OTA and place on the ground somewhere reasonably clean (vertically ?), then move the base, and then come back for the OTA and put that on the base again ? Does it slot back in simply or do you need quite a bit of light to see whats going on & to tighten things ? I woudnt fancy having to take the OTA back inside the house for such a manouvre.

[Ben Ritchie]

Or can you just take off the OTA and place on the ground somewhere reasonably clean (vertically ?), then move the base, and then come back for the OTA and put that on the base again ?

Exactly this. To move it I just remove the OTA from the base and place it vertically (i'm almost always observing from a paved surface in my garden, but use a groundsheet on grass). It's designed to be stable that way. I then move the base to the new location, carry the tube over, and then...

Does it slot back in simply or do you need quite a bit of light to see whats going on & to tighten things ?

...the tube rests on four teflon (?) bearings on the base, and is perfectly secure that way - the handles then screw in to hold it in place. One also acts as a tensioner to set the resistance for moving the tube around. Easy to do in complete darkness, although i'd suggest some light for the first few goes.

One of those things where a picture is worth a thousand words, but it's pouring here - otherwise i'd take it out and snap a couple of pictures!

[Ben Ritchie]

By the way, if you search back a few months on this forum (anybody find a link? I can't!) you'll find a thread started by me where I was pondering the 10" or 12" solid tubes, several people said that i'd be fine with the 12" and they were quite correct

[jonstarrysky]

Thanks Ben. The 12" solid tube is starting to look my option. Not sure I saw the forum you allude to yet. One thing is as focal length has creept up to 1500mm, with my expanding desire for aperture, my lovely 24mm Panoptic (currently gives me my widest view with 1.25"-only focusser on my 900mm focal length scope) will start to be not so wide true field of view. I will need 35mm panoptic or equivalent + paracorr. Expensive !!!

[Ben Ritchie]

Ah, here's the thread I was looking for from when I was looking at the 10" vs. 12" question

http://stargazerslounge.com/index.php/topic,33789.msg345152.html#msg345152

as for eyepieces, another option to consider is the 28mm UWAN, a really nice 'ultrawide' without the stonking price-tag of the 31mm Nagler. Personally I don't find coma too bothersome with it, although it's certainly present of course - my suggestion would be to wait and use the 'scope for a bit before deciding if you need a corrector or not.

[M110]

I have the 12" solid tube and don't have any problems moving it around (split into the OTA and base separately), its the bulk of the tube rather than the weight that causes the odd problem - I just have to be careful not to bang it on the garage door when I'm getting it out! scratch one finderscope....

The movement in both the alt and az is smooth - especially since I greased the azimuth bearings yesterday, silky smooth now!

Light grasp is great - a huge step up from my 6" refractor. M42 is simply stunning through a scope of this apature. If you've got the space to store then I'd go with the 12" solid tube any day (although if you do travel with it I'd measure the back seat of the car first to make sure it does fit!).

regards,

Alex

[kniclander]

tbh jonstarrysky, I am glad I started with a 6" so I can appreciate a 10". the difference is really big and not just dsos - also planetary resolution. Nb collimating the 6" is a cinch; the 10" is quite tricky and has to be really spot on.

[ZOG]

If you want portability go for the 12" flextube. I love mine, the OTA and mount go into the rear of the Octavia, and I'm 54 and fairly unfit but I can handle it in 2 parts no problem. A light shroud is easy enough to knock up to fix any LP problem. It's just a really easy to use big scope, I really wouldn't fancy trying to take a solid tube 12" to a dark sky site and try to set it up myself.