Deep Sky Observing

[Wolfsong (Chris)]

G'day all,

I've been Observing for a while now with my 130mm Skywatcher Newt on EQ2 and feel it's time for an upgrade. I Have fallen in love with Deep Sky Objects.

Now last few months I've been doing some homework on-line as to what Telescope would suit me best. And have learnt the inevitable truth that apature and/or imaging is my solution.
I didn't start out the hobby with imaging in mind but I'm not set against it. And who doesn't appreciate appature

I live on the NW Coast of Tasmania which has it's pros and Cons.
(Pros = Plenty of beautiful Dark sky areas to choose from with low to no Light pollution.
Cons = No Clubs or Hobbyist around for me to take a peek through different scopes and get advise)

There are 2 scope that I'm interested in:

1. The 16" Skywatcher Goto Dob (a bit bulky)
2. The Celestron CPC 1100 SCT (is it SCT good for DSO??)

Both are larger Apature, both fit in my ute, both around the same price tag and both have the Goto and tracking.

Please help guys, I need some advise as I want my next scope to be a good investment

[barx1963 (Malcolm)]

Hi Chris and well done o0n moving up to a new scope.
Pros and Cons of the 2 scopes
SW 16" Go To Dob
Pros
- Aperture, with 16" you are into serious observing territory, in dark skies virtually all the NGC and IC onjects are available, as well as numbers of PGCs and other catalogues. Smudges will turn into detailed images
- Mechanically simple
- Can be used manually without the Go To
- Has Go To so quick to find objects if navigating is not your thing
- Collapsible
Cons
- Can be bulky
- Requires collimation, at 16" and I think f4.5 collimation is essential

Celestron CPC1100
Pros
- Reasonable aperture
- Long focal length makes smaller objects such as PNs easier to see
- From what I have heard, Go To in these scope is reliable
Cons
- Smaller aperture than the 16"
- More reliant on motors and electronics so more to potentially go wrong and dependant on batteries or a power supply

Those are just a few ideas that jumped into my head on reading your post, I am sure others will be able to suggest others.

Malcolm

[Wolfsong (Chris)]

Hello Malcolm and Thanks for your reply.

Yes the Dob has the clear advantage with the extra 5" of apature and the the abillity to star hop manually rather than automated slew if I wanted to.

The lack in information I found in the SCT abillity for dso just made me wonder if the 2 are even comparable for DSO work.
Your comment on the SCT's abillity to enlarge Planetary Nebula was interesting.

Considering the extra apature for price range, the size and bulky-ness of the Dob not being an issue and my driving NEED to want to see deeper into the void makes the 16" a better choice.

You also mention an interesting aspect which I never considered and thats the SCT"s reliance on electronics and power (time limit of opperation out in the field) and malfunctioning parts.

I've in the meantime (while making my choice) ordered a few accessories :

1. OIII and LP Filters
2. 5mm and 24 mm Orion Stratus eyepieses
3. orion lazer mate
4. Telrad
5. and MORE books on DSOs and catalogues

[NorthernLight (Max)]

Hey Chris,

take the dob, mate! Add a barlow lens if you want the same focal ratio as the CPC to observe those 0.2' PN´s.
And get an observing chair for it too. It gets quite painfull in the back when you try to look through the eyepiece with a bent back at certain elevations of the tube.

As for photography, I wouldn´t recommend any of the two. The Dob would be next to impossible to mount on an equatorial mount and the SCT would require something like a G11 or CGE and would be hard to guide with it´s 2.7m focal length.

Greetings over the ditch!

[Poita (Peter)]

Or, as a totally different tack, you could look at a small fast refractor on an EQ mount (A HEQ5 would do) and a mallincam type setup.
You get 'live' views of many DSO objects, and many with full colour, in many ways in greater detail than you get through the eyepiece of even a huge scope.
It is easy to transport around too, and allows for basic photography as well.

Check out the Night Skies Network for more details of 'video astronomy' for DSO lovers it can be a revelation.
http://www.nightskiesnetwork.com/

Ken could probably supply you with more info, see his (old) thread here, you could PM him for more info.
http://www.iceinspace.com.au/forum/s...ad.php?t=74529

[Poita (Peter)]

For photography you could go the Hyperstar route for the C11
e.g. piccies:
http://donastro.blogspot.com/2010/09...da-spiral.html
https://arizona-observatory.com/info...trophotography
http://www.otticasanmarco.it/images/...foto_C11_1.jpg
http://starizona.com/acb/hyperstar/cometlulin.aspx
http://www.hyperstarimaging.com/gall...lery.php?cat=2

Details
http://starizona.com/acb/HyperStar-L...-P990C648.aspx
http://starizona.com/acb/hyperstar/whatis.aspx

[Allan_L (Allan)]

Having just sold a fantastic CPC1100 and having looked through a few large DOBs, I can say that the above advice from Barx and northern are good.

and Poitas suggestion sounds interesting, although this is new to me and something I need to investigate.

The CPC1100 is a fantastic machine.
Great optics, good magnification FAST and EASY to set up and align
GOTO is precise (depending on accuracy of initial alignment, and balance of machine and accessories).
Mine never ever needed Collimation from originally set.
However, balance can only be achieved with an add on counter weight system (IMHO).
And if power goes you are pretty much stuck. (but you can disengage both drives and move manually but this is not too precise).

The Bigger DOB is not as easy to set up, probably requires more cooling of the big mirror, probably needs to be collimated every outing, and is more susceptible to WIND.
Also, not all GoTo systems are created equally, but push to is a definite advantage, which is available on some GOTO machines optionally.
However, the greater Light Gathering capacity makes it a definite winner in my experience. You will see DSOs that you can only see in the CPC by using "Averted Imagination".

And Northern is right, in that Neither is an acceptable option for semi serious astrophotography.

Good Luck with your decision, and feel free to ask more questions.

[Wolfsong (Chris)]

Thank you barx, NorthernLight, Poita & Allan for all your sound advice guys. The Goto Dobsonian is what I'll be getting then.

I love my visual observing and not really into the photography side of things (for now). So I'll be very Happy and content to just be able to view the DSOs

I've been looking at different brands as well :

1. Skywatcher I'm familiar with and has good build quality and optics. I Like the features of the SkyWatcher 16" Synscan GOTO Dobsonian. (because of the collapsible Tube)

2. Meade is Good too I quess, have read some good reviews (optics) and fair reviews (about fit and finish on their mounts.) [...this is all objective I suppose.]

3. Orion. Now Orion Skyquest XXg 14" Goto Truss Dob intrigues me (not sure if Orion make a 16" truss Goto Dob). Have not found any reviews yet but looks good (even with the 2" inch less apature)

Man , I wish I could have a look at and/or through each telescope in person

Any thoughts on the matter of Brands?

[Allan_L (Allan)]

Originally Posted by Wolfsong

Man , I wish I could have a look at and/or through each telescope in person

Any thoughts on the matter of Brands?

I have looked through an Orion 14 inch truss "Push To" model.
And am blown away by the views.
there is one regularly at the Pony Club if you are in the area one Saturday near new moon.

If you want a detail review, Rick Petrie posted on, or you could just ask him.

[mental4astro (Alexander)]

Hi Chris,

Before you lay your money down, it wouldn't be right if no one challenged your "wanting" of a goto scope is the right one if you are just after a visual instrument. There are certain physiological reasons why it would be advantageous to keep the scope "push to", that is only manually moving the scope.

Our eyes are made to detect movement. Keeping a dim image stuck static in the field of view will cause your eyes to become staturated and not as responsive to what is actually visible.

My passion in this hobby is sketching at the eyepiece. I considered motorising my 17.5" dob until two experiences changed my mind.

The first was a sketch I did last year of the Swan Nebula. I noticed that with even just a slight jiggle of the scope I actually saw fainter detail than with a static scope. This jiggling of the scope is an old observers trick which I have myself employed for many years, but this particular sketch affirmed that I didn't need motorising the scope.

The second was the non-motorised 25" scope of a fellow sketcher Alex Commino, qld here on IIS. For the reason noted above, Alex only has digital setting circles on his big dob to help locate objects.

In fact, even digital setting circles are also not necessary, even with giant dobs. I recently used a 36" dob that is totally manual. No motors, no digital setting circles, only a battery of finders set up next to the focuser and down at ground level. It did have the full kit & kabboodle of gizmos, only to have them ALL ripped out as the scope's owner found he didn't need them and he wasn't enjoying himself anymore with all the gadgets!

The money you save on keeping the scope push-pull you can spend on some really nice EPs and a filter or two.

Food for thought.

Alex.

[barx1963 (Malcolm)]

Well said Alex, there is a lot to be said for good old hand powered push to mounts!
Another thought Chris, you made a comment that you wished you could look through some scopes. The size scope you are talking about is quite large.
I have a 12" solid tube dob. I had it in the back of my car on Friday at work before heading to Snake Valley and a work colleague commented on how big it was and at first he though I had a hot water system in my car.
If you buy a scope unseen in these sizes you may be shocked at how large, heavy and cumbersome they are. Especially when you consider setting up and taking down in the dark! If you can get to see one in the flesh that is a good idea.

Malcolm

[Vegeta (Ibrahim)]

hi all,
The 16" dobsonian would be a lot better for visual DSO than the 11" SCT due to the extra 5" of light gathering power.

I agree with Alexander in that a manual dob will be more enjoyable. The GOTO and tracking capabilities would be handy, but it sort of defeats the purpose of visual astronomy. I personally prefer the "hunt" for DSO's.

Hope this helps and Clear Skies

[Poita (Peter)]

The big question is how many nights a week/month/year do you realistically expect to be able to spend under the stars, and how many hours on those nights do you want to be out there?

If you are a night owl, and don't have other pressing commitments and get lots of decent weather, then a push-to system is very fulfilling and satisfying, as you get to have the challenge of star hopping and seeking out those elusive fuzzy blobs.
I spent most of my time in the late 80s finding plenty of objects with a C8 balanced on the roof of my car, and without a finder(!) and could find most anything by eye. But this was after many years of floundering around and getting to know the sky, I was never a 'sleeper' and had no commitments so enjoyed that time to myself and the satisfaction it would bring.

If I was starting out now, I would grab a fast to setup accurate goto unit and grab a mallincam. I don't get anywhere near as many nights outside as I would like, work and family commitments mean I can't have as many 'astro-hangovers' from lack of sleep, and I'm not as young as I once was, and the nights I do get, the weather often cuts them short.
If I didn't already know the sky a goto would be a godsend as I could 'take a tour' of the interesting things to see on any given night, and get to see a range of interesting objects in a relatively short period of time, as well as find those bloody difficult to find jobbies.
With a mallincam I can use a smaller scope and see more detail than I can with my eyes, and get to see colour as well. it is instant gratification, which may not always be as satisfying, but depending on the amount of hours you have at your disposal, and your experience, then you may find you use a goto system more often.

It is often said that the best scope is the one that you use the most. Get to a gathering and take a peek through some beasties before you put any money down, if imaging may be in your future, consider a smaller refractor on an EQ mount and a mallincam, it will be easier to transport, fast to setup and will be a good basis for an imaging rig down the track. You can learn stacking etc. with the mallincam as well, and migrate to a dedicated CCD down the track if the bug bites you.

If you think you will stay visual, then get a look through some big dogs first, they may not offer the extra image pull you expect, or then again, they might blow you away. For me the incremental amount of detail between a 10" SCT and a 16" DOB isn't enough to make up for the extra size and hassle especially when I see more detail on DSOs (clusters excluded) via a 80mm refractor and a video camera.
Every person's experience, situation and expectations is different, get a look through some scopes before spending the $$ and you will be much happier!
Maybe make the trip to Hobart to visit Graham if he is of a mind to show off his gear?
http://www.iceinspace.com.au/forum/member.php?u=5952

[Poita (Peter)]

There is a good broadcast on right now:
http://www.nightskiesnetwork.com/liv...php?n=johneez1

[Wolfsong (Chris)]

Thank you guys for all your input.

Lot of different views and opinions. I like that.

Alex you made mention of a push-to being better than a goto and the reason seems quit valid.

I seem to agree with Poita as well, in that I too don't get much time during the week to observe.
I do however love packing the camping gear and the scope in the ute and heading to a new darksky spot practically every weekend (except maybe winter here in tassie )
So time is an issue for me and one of the reasons I like the Skywatcher 16" Goto synscan Dob is, that it has a dual encoder and thus I could move it by hand and the alignment would not go out I would still be able to use the goto straight after pushing it 180 degrees say.

Best of both worlds.

I actually like the big old Dobs so size is not such an issue, frankly it's quite appealling.

I don't think I'll get time to travel to Hobart or the mainland anytime soon...I would definetly love to pop in to a few clubs and have a look through one or two.

anymore input will be appreciated.

[mental4astro (Alexander)]

Think also about how you would like your observing session to happen. By that I mean do you just want to rip through as many objects as you can, or plan a session for selected targets. And then there is everything inbetween.

You are asking opinions, I can only give you how I approach this hobby now after 30 years.

My time, like yours, is limited. For me now it is about setting up with the least amount of fuss to be at the eyepiece for as long as I can. The electronic gizmos, for ME, only got in the way. A finder and good chart is all I need. The hunt is the appeal as much as the sketch. It is slow and easy going. Home life and work is manic enough, I don't need the same level of frantic pace in my hobby. It is my unwind time.

Look, if you like going camping, consider that you are there to get away from it all. Don't only think that a Goto is only about packing in as many objects as possible. I think it can be a trap many folks fall into. It is a powerful tool, but only in wise hands, otherwise you are really only just a hoon in a hotted up space buggy.

All I'm saying is think about what appealed to you about astronomy that had you go out and get a scope and then stick with astronomy after the initial romance wore off. What kept you going back to you 130mm reflector even after you realised that the image through a scope was nothing like those pretty pictures. It wasn't tear arsing from object to object.

A goto can be a fine investment. Just don't confuse quality time with quantity of objects, .