What can I see with a...

[shenanigans000 (Greg)]

Hello all.

Well I finally have saved and scrimped enough dosh to get a proper telescope, to replace my Chinese ebay 6 inch newtonian.

I'm currently torn between a 10 inch SCT eg Meade LX80, for it's portability and potential future AP use, or a 12 inch goto dobby eg Skywatcher collapsible, for it's light gathering ability

Both 'scopes are similar prices so it's going to come down to what I can actually see through them.

I'm mainly interested in deep sky objects.

How much real difference do you'se think there is between the two, visually?

And, will I be able to see colours in nebulae with either, or are they both too small for that?

Any thoughts are much appreciated.

[RobinClayton]

With both - you are not likely to see any colours - our eyes are not adapted to such light conditions.

deep sky objects are more dependent on local light conditions - if you can get to a really dark site - that is much more important than having a great telescope.

to get colour in nebula - they usually take a series of photographs with different colour filters - then combine the photos. it is not normally possible with normal vision.

[raymo]

You've got several different aspects of scopes to consider here.
1/ A 12" GO TO Dob is one big mother to be moving around frequently, but
fine if it is going to stay in one place, or you are built like Arnold
Schwarzenegger, and have a fairly roomy vehicle. There is a fine line
drawn where a scope becomes large enough to make you sick of
moving it around, and ends up being under used, or even abandoned
all together.

2/ For serious astro imaging the 10" SCT is more suitable, as the
tracking is better, and the short tube is more wind resistant, and
there are counter weight systems available to counter the weight
of the imaging equipment you will hang off the scope. Quality
imaging also demands really good collimation, and the SCT will
retain it's collimation for far longer than the Dob. Neither scope
is the best imaging scope around, but I would go for the SCT every
time.

3/ As far as what you can see through each scope is concerned;
You won't see much colour in nebulae with either scope.
With average colour perception you can see a faint but definite
tinge of green in M42 for example with the 10" SCT, and it is only
marginally stronger in a 12" scope. I find the only significant
difference between the two scopes is when observing dense star
fields, and very faint deep sky objects, when there is a noticeable
[though small] improvement.
I hope this helps
raymo

[shenanigans000 (Greg)]

Thanks for that information.

From the previous am I right in summarising that, visually, there isn't much difference between between the two?

If so than I'd have to say I'll go with the SCT - it looks to be much more portable.

[Davros (Lauren)]

If you are serious about starting imaging find yourself a second hand ED80 refractor plus HEQ5. Then match a DSLR to it and you wil get your colour.

[raymo]

I hear what Lauren is saying, and that set up would be great for AP,
but as your only scope an 80mm APO falls woefully short in the
visual observing department.
High quality AP only comes with experience and much learning
of all facets of the subject, so I personally suggest that the SCT will
give great observing, and pretty good AP results, and further down
the track you can move to a refractor for AP if you yearn for the best
possible AP results.
raymo

[Allan_L (Allan)]

I remember reading this recently about the same debate.
I thought it may help.

Originally Posted by ausastronomer

Hi Greg,

I can't agree with this comment at all.

There are a whole lot of reasons why someone might choose a SCT as their scope of choice for visual astronomy, including convenience, lack of storage space, or dual purpose as an imaging platform.

The quality of the views isn't a reason anyone would choose a SCT, unless they don't know what they are looking at. Look at all the specialist visual lunar/planetary observers, look at all the specialist double star observers, look at all the specialist variable star observers, look at all the specialist deep sky observers, you will be lucky if you find any of them using a SCT for visual work.

The pure physics of the design precludes them from being the optical equal of a newtonian or a refractor.

1) Large Central Obstruction
2) Closed tube design with corrector plate hinders fast cooling
3) More air to glass surfaces introduces additional aberrations and light loss.
4) The optical quality of the scopes themselves in many cases is poor. Although there are a few good ones. I just haven't seen very many.

Mark,

If you don't plan on imaging in the foreseable future I would be giving serious consideration to downsizing your current 12" newtonian to a 10" and being done with it. Sell the 12" on IIS and buy a 10". There isn't a huge difference in the views, but there is an enormous difference in portabality, particularly if you went with a collapsible tube version. A 10" newtonian is going to be a better visual scope on just about every single target as compared to a SCT or RC.

If you do plan on imaging one of the Advanced Come Free scopes would be a good choice as an "allrounder".

Cheers,
John B

I have recently moved from an 11 inch SCT to a 10 inch collapsible DOB and agree, I can see more with the smaller DOB than I could with the larger SCT.

[Davros (Lauren)]

The standard fist 'real' scopes seem to be a ten or twelve inch collapsible Dob if you want visual or a HEQ5 and ED80 if you want astrophotography.

[rustigsmed (Russell)]

i can't comment on the SCT; here is my flickr page http://www.flickr.com/photos/80336656@N07 i have the SW goto 12". it might give you some idea. its a nice scope, however i'm looking at getting an astro-photograhy dedicated scope at the moment. I'll probable keep the SW12" for visual and/or planetary photography.

if i were to do it all again, i'd probably get a NEQ6 with 8" reflector (or ED 80) and then 12" dob or 16" dob with no goto tracking for purely visual use. then you've got the best of both worlds.