Dob vs se

[Digger1895]

Hi everyone,

I currently own the SW 130p Dob as my first scope which I've had about 8 months and have decided to upgrade.

I've decided I now want goto but not sure which way to go.

It'll be either a SW 8" flex goto Dob or a cheap(er) type of SCT like the Celestron 8se (I know I could get a bigger goto Dob for the price of the 8se but at the moment 8" is as big as I can go practically for a Dob).

I am not interested in AP and have never used a SCT so would like to know which is the best all round performer,

Cheers.

[NGC 1502]

Both those scopes are a good choice and will give nice views of a wide range of objects.

Dobs - usually faster cooling, capable of lower power / wider field, but need a bit more upkeep like collimation and occasional mirror cleaning. Usually need better eyepieces to get sharp to the edge views.

SCT - compact closed optical system, take a wide variety of upgrades.  Mirror reversed view assuming use of a diagonal.  Needs a focal reducer to get wider low power field. Larger central obstruction in theory reduces contrast, but that wouldn't stop me getting one. More prone to dewing up of the front corrector, but this can be sorted with a dew shield or Kendrick heater band.

None of the above is a deal breaker or a reason to get one or the other, both are popular choices. There's no knockout punch in the above.  

If you can get to a dealer with showroom stock, that would be a good help in deciding, nothing beats seeing equipment in the flesh.

Best to ask around, read reviews, hopefully others will see this and offer their advice with points I've missed.

HTH, Ed.

[davedownsouth]

Hi Digger, where do you live?  Are there any groups near you which you could visit and try out some similar scopes.  Because of the cost of these scopes, you do not want to get some thing you are not completely happy with.

[lonebod]

Hi mate. I got the SW 200p flextube the goto one. It's great...... But I wish I'd got the Celestron c6n now. Then I could have bought another ota to use the same mount.

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[lonebod]

http://www.firstlightoptics.com/advanced-vx-goto.html

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[Northern Soul man]

Hi Digger and a very warm welcome to the SGL mate.  the 8" will be a great performer, the dob Vs the SCT is, I think, a dilemma that a lot on here have gone through, the SCT (with a longer focal length) will give you a slightly larger image scale on the Planets/moon - so they will look slightly larger (but not by much) for a given mag in the SCT - when conditions are favourable (excellent seeing, scope cooled, object near opposition, highest point in the sky) the SCT on the Planets work very well, if you can put up with a smaller FOV, the smaller Messier's will be fine and if your not into the large star fields, the SCT would be nice, the Dob will give you "nicer" looking stars (I've found the stars in an SCT a little more "bloated" than in a Newt) if you like the diffraction spikes and a larger FOV for the more extended objects.

Its going to be a tough call for you, I have settled on the SCT over the Dob/Newt and really enjoy the views through it - Alt/Az mounted with GOTO is a pleasure to use, accurate and once aligned on the Planets - a comfortable viewing position  -I can sit there for hours just looking at the Planets - its nice just to pick a constellation and just work through all the objects visible - there's nothing like being a little frustrated searching and sweeping for an object which is invisible - not the scopes or observers fault - just down to the light pollution making it invisible  -So I just try and see each object by checking the magnitude first in the handset and spending a little time - maybe increasing mag to darken the background sky a little - you find a lot of the star clusters can be seen with a little sweeping around - I find this acceptable and the small FOV doesn't worry me - just depends on what you use the scope for - I find the open clusters and large star fields much better in Bino's with a much larger FOV - even than the Dob/Newt.

Regards.  Paul.

[lonebod]

So you know, I've got the SW 200P flex goto. Got excellent view of planets and dso's too. Just remember, ACT's need dew shields and dew heaters, bit dobs need culmination. You'll also need a powertank for the goto. Then once you've broken the bank, you'll start saving for decent EP's.

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[lonebod]

Thant should say SCT not ACT....

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[rowan46]

The main reasons for choosing  dobs is  ease of setup and price per apparure. When you add goto to the mix the decision is not quite so clear. Setup is pretty much the same, The 8se wins on portability and the dob wins on cost. The views will be pretty much the same for a given magnification with the dob giving a wider better framed view for dso's and the sct giving more magnified view using the same eyepieces. The sct being a longer focal length will be more forgiving of eyepieces. Both are good scopes so its a tough call.

[Astro Imp]

Why do you feel you need a GOTO set up? Is it because you like the idea of tracking or to help find objects? If the latter have you considered Orion Skyquest  XT8 Intelliscope http://www.scsastro.co.uk/catalogue/orion-skyquest-xt8-intelliscope.htm which is considerably less than a GOTO Dob and you won't need a power tank. 

Just a thought.

[Sandraj]

Why do you feel you need a GOTO set up? Is it because you like the idea of tracking or to help find objects? If the latter have you considered Orion Skyquest  XT8 Intelliscope http://www.scsastro.co.uk/catalogue/orion-skyquest-xt8-intelliscope.htm which is considerably less than a GOTO Dob and you won't need a power tank. 

Just a thought.

I have been drooling over that scope as a possible future upgrade.

[lonebod]

In defense of goto especially if your wanting to be able to get young children involved in astronomey, it's brilliant. I can set up my scope in 5 minutes and let me daughter (5 and a half) see several objects in the sky before her attention span means she's more interested in the box my EP s are stored in. And when she's not around it's helped a newbie like me learn when things are in the sky.

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[Digger1895]

The main reason for wanting goto is tracking, I have thought about a pushto system. Plus most of my viewing is done from either my back garden in Brisbane (I'm from East London originally) or my balcony. Both are restricted to northern views from here but neither new scope would fit on the balcony so I would keep the 130p up there.

My main concerns, as also pointed out here, are Fov on the SCT and portability and set up (collimation etc) of Dob. I also like the finding of objects in goto as a time saver. I have used star hopping on current scope and sometimes the thrill of the chase can turn into frustration, I am going to get a Telrad for the 130p, that might help some. I've also thought about an EQ mount but have used other peoples and they're too fiddley for me and you end up in some strange zen yoga type positions.

So, I know about the portability and set up problems of the Dob, but not the FOV on the 8se. What are these like for DSOs?

Thanks all for your time and posts, they are appreciated, I am a member of an Australian based forum (that's not where the Digger tag comes from btw) but they seem pretty stuck up and pompous,

Cheers

[rowan46]

you will get most dso's in the field of view of a c8 

[Digger1895]

Is the C8 the same OTA as the 8SE but on a GEM? Every time I read or even re-read something I swing from one scope to the other. Today at work I got talking to a client who I didn't know was into astro and he was trying to talk me into buying a large APO frac, maybe I'll save up for that once I've decided which of these two. At the moment I think I'm leaning towards the 8se, does anyone know a ball park figure for the total weight of scope, mount and tripod when assembled? Oh, and now I've thought of another thing, is the 8se's tripod good and sturdy, I can't remember hearing of it not being.

[hobsey]

Is the C8 the same OTA as the 8SE but on a GEM?

Yes they are practically the same OTA just with slight differences, like the dovetail being in a different side but the optics are the same.

[CodnorPaul]

Is the C8 the same OTA as the 8SE but on a GEM? Every time I read or even re-read something I swing from one scope to the other. Today at work I got talking to a client who I didn't know was into astro and he was trying to talk me into buying a large APO frac, maybe I'll save up for that once I've decided which of these two. At the moment I think I'm leaning towards the 8se, does anyone know a ball park figure for the total weight of scope, mount and tripod when assembled? Oh, and now I've thought of another thing, is the 8se's tripod good and sturdy, I can't remember hearing of it not being.

The SE mount is not sturdy at all - the tripod can be tightened up to be fairly solid but the mount itself wobbles when focusing and when windy.  It made it unusable to me so I upgraded to an NEQ6.  If you go for the SCT get one on a GEM mount and you wont regret the purchase at all - fabulous scopes

[Digger1895]

Oh dear. Thanks Paul, maybe I should have asked that question at the beginning. I too can't use wobbly tripods/mounts, it drives me insane having to wait for scopes to settle then start wobbling again if you touch the focusser.

It seems you have answered my question and I'll be going for the Dob,

Thanks all for your advice.