CPC XLT 925 (Celestron) vs 14" Goto DOB (Skywatcher)

[sirmetin]

I keep yo yo ing between these two scopes. I believe I can get either in my car so Dark sky trips are possible (Don't think the 16" Dob would go). However a good deal of viewing will be in the back garden where there is a fair amount of light polution (steetlights are shielded well by the house).

What are the pros and cons of these two scopes. The consideration is for viewing only

Seperate question is there any benefit in making a jacket to go round the truss tube area (or maybe there are commercial ones) particularly if there is stray light around?

[brantuk]

You can get a shroud for the dob trusses - this is what you'll need but you may have to enquire about the 14" ones:

ScopeStuff

I had a similar dilemma of choice - you can see how I resolved it in my signature lol

[swamp thing]

Hi

If it's to be your only scope the 925 will probably get most use, as it will be easier to live with on a daily basis.

If it's not your only scope go for the Dob.

Big Dobs are awesome from dark skies but from suburbia they are IMO not worth the extra effort of lugging about. The picture like views that they can deliver are only seen from dark skies. from suburbia all will be faint fuzzies.

So if it's your second scope you can pick times and places to use it when the views will be breathtaking. Not forced to lug a huge lump into the back yard every time you wanna observe.

Just my 2p's worth.

Good luck with your choice

Regards Steve

[SteveL]

One other thing to mention is that the CPC925 is f/10 while the dob would be probably a f/5, which would make a huge difference in what could be seen visually.

[faulksy]

has to be the cpc. 1 word to describe it awsome

[LeeB]

its a bit of a chalk and cheese question, i agree with the above the difference inf numbers makes comparison difficult, for my vote a big dob but lugging has never bothered me.

[mert]

One other thing to mention is that the CPC925 is f/10 while the dob would be probably a f/5, which would make a huge difference in what could be seen visually.

Could you elaborate on this please?

[bish]

Both excellent scopes. The CPC925 should be easier to handle. A 14" dob is a lot of scope. If it were me buying for visual use then I would go for the biggest scope I could manage. Steve makes a good point but I would say that a big dob will mean that you can find more DSO's under light pollution. I can only speak from experience of starting with a 6" and now using a 10", which are both fairly portable, however.

[evilgeenius]

I bought my first scope a couple of months ago, a CPC925. It's an awesome piece of technology.

I thought about getting a dob as you get more aperture for your buck, but being the gadget geek that I am, and knowing I wouldn't have the patience to spend a lot of time finding targets, i decided to go for the go-to option instead. I have it connected to my laptop using the free planetarium software Stellarium. It allows me to take total control of my telescope just by clicking on the object within the software, it's geek heaven really.

Also I wanted to try my hand at astrophotography which you can't really do with a DOB.

[Ptarmigan]

You can get a shroud for the dob trusses

,,,,,

I had a similar dilemma of choice - you can see how I resolved it in my signature lol

Nice one ! I may have to adopt that solution myself !

My wife is handy with a sewing machine, what sort of fabric would be good for this use,

( I've not asked her first - so I will deny all accusations of conspiracy )

[sirmetin]

I was going to use blackout fabric (used for curtain lining) and treat it with a waterproofing agent

[Nexus 6]

good point made by swamp thing (Steve), I cannot comment on the dob really as I actually use the 925 and have been for 2 years now. I would imagine that the dob would be the easier to transport and would provide some outstanding views from a decent dark sky location.. Other factors are also worth noting like cool down time, open v closed tube design makes the dob much the quicker for getting out to use. I would say that it is only after a couple of hours that my 925 starts to provide a nicer visual image although I am usually out using it within the hour.

Hope you enjoy the views which ever you choose

[Ptarmigan]

I was going to use blackout fabric

Gosh ! That's a blast from the past,

Is that still sold !!

I was thinking more in terms of fluff-free, ie. should it be cotton, linen, man-made etc

[Pingster]

Have you considered the C11? As that would work well from home, and even better from a dark site.

I have a pair of x15x50 bins on a paragon tripod(coverted so i can use it in a recliner), a celestron 8se and a 16in dob.

The bins easily get most use, almost 3 times a week. The 8se i use from my back garden on planets and the moon. For DSO its not so good from the city. The 16in... i love the thrill of driving it out to a dark site and seeing stuff the other two equipment can't touch.

If i was to do it all again... i would get a Quantum 7.4 25x100 binoculars, becuase you can change the eyepieces giving you the convience of a binoculars... yet using higher powered eyepieces you can start to achieve the results of a small telescope. Theres somthing so beautiful and simple about using lower mags.

And i'll still have my 16in Dob. The thrill of driving it out to darker and darker sites, i love it. The views are awesome too, and keeps my app fever at bay.

[Ben Ritchie]

They are really rather different 'scopes, so if at all possible i'd suggest getting yourself to a sky party and trying them out before committing the money - there's really no substitute for hands-on use in helping you to decide.

The problem with SCTs is that they are very long focal length instruments, and so have limited fields of view. However, they're compact, capable, do everything reasonably well and aren't demanding when it comes to eyepieces (the long focal length makes them demanding when it comes to mounts IF you want to image, but that's not an issue here). At a given price point dobs give you more aperture than anything else, so show more, have a shorter focal length (and hence wider field of view) but really need more of an investment in eyepieces and a coma corrector at lower powers. Collimation is more critical to get the best out of them.

Given that you talk about 9.25" vs. 14" I get the feeling you're buying at a price point, and i'd suggest that's not the best thing to do here. While it is a large aperture difference, it is also a large difference in portability. The 14" is a big 'scope, and not easy to handle on your own, so my suggestion would be to forget aperture here, and look at a 10" Dob, possibly a 12" instead (again, REALLY useful to see the two sizes in person if you can). With a smaller Dob you'll get better portability, save considerable cash, and the practical difference between 10" and 14" is not as huge as you might imagine (12" -> 14" particularly so). And I say that as a 14" owner.

So i'd suggest a 10" Dob, some decent eyepieces, and a few extra tanks of petrol for your car to get you to dark skies. The 10" will be simple to handle and setup on your own, will show lots, and IMO will outperform the C9.25 for visual use. If you really get hooked, start thinking bigger. I'd personally suggest forgetting the GOTO as well as it's easy enough to find things with a bit of practice, and then you get to ditch the electrics too.

[sirmetin]

I think the 12" may be a good alternative - it wasn't buying to a budget it was a case of not considering the CPC 1100 as good value (almost £600 more) and I don't think I would be able to fit the 16" in the car or for that matter easily lift it in. But both the C1100 and the 16" skywatcher are possible if someone could convince me either would be a better idea.

[Pingster]

I have a SW 16in flextube. Its a fantastice scope and cured my ap fever. Becuase i know know what can be seen with a 16in, which is a huge scope. So i know that going up any much more is not a good idea unless i move out to a location with consistantly good clear skies, and build an obsy. Since there no chance of that happening... I dont keep onnwondering what a bigger scope will look like.... Well at least not for now xD

I can confirm that the 16in is pretty much impossible gor one person and you will have to break down the base if you wish to transport by car, in a people carrier the vase will just about fit in one piece. But the tube itself is far too heavy to be carried and mounted alone. I would not recommed it as a first scope. I have not seen the 12in or 14in version in person, but i gustimate that the 14in will still be far too big, but the 12in just might be managable.

The only reason i suggested the C11 is that it can be mounted by one person, will fit in cars, an 11in is pretty good ap.

If i was in your situation, i would choose a 12in SW dob as long as you have an iphone to run starmappro which is great for locating DSO's.

[mert]

I had a 12" Skwatcher flextube synscan dob, it is managable and even fits in the back of my small hatchback (Suzuki Ignis 5 door) stand and scope (unboxed) It was fairly easy to carry out to the garden and setup, the base is a little akward but fits through door in the house, the scope in easy to carry especially the flextube.

As for the 14", may be a tough job moving it alone, especially the stand.

[brantuk]

I fit a CPC925 and a SW 12" Flextube Dob in the back of a Volvo estate if that helps at all - a box and 5 flight cases too lol.

One point about f10 and f5 focal ratio scopes is that the slower focal ratio will be more tollerant of "not so good" eyepieces. So an f5 dob really begs "good glass" to get the very best from it being an altogether faster device.

However the slower focal ratios of an Sct will give sharp and contrasty focusing - especially on planets. Of course you can get a reducer to bring the focal ratio down and speed it up (6.3 typically) for dso imaging/observing. To there are a lot of options and trade off's when picking the right scope.

The C1100 sounds like a great compromise of aperture, portability, and flexibility imho

[Ben Ritchie]

As for the 14", may be a tough job moving it alone, especially the stand.

Unless you're built like a weightlifter the base of the 14" is pretty much impossible to move any significant distance on your own, with two people it's luggable over short distances fully assembled. It's designed to be broken down into components fairly easily, although i'm unsure how well it would cope with regular disassembly

The 14" OTA is just about liftable by one person, but it's very cumbersome.

[sirmetin]

Funnily enough I used to lift weights - around 500lb deadlift and 430lb Benchepress 500lb squat. So once upon a time it wouldnt have been a problem, I did recently lift a 76Kg safe out of the back of the car but I wouldnt want to do that more than once.

I am aware that I would need better EPs with the Dob but then again if I get a focal reducer for an SCT at F6.3 it probably won't be that different. I have had both Baader Hyperion and Celestron X Cel LX so far but should I be thinking of better? If I buy a 12" goto Dob I would be able to get a CGEM and around a £500 refractor.

[Nexus 6]

Looks like I definitely under estimated the size and weight of a 14" dob, have seen and looked though a SW 12" only the once so based my thoughts on your choice from that sirmetin. I would prefer to move a 10" or 12" dob than my 925.

[Merlin66]

If you are serious about visual only, then a 10" dob is a very workable compromise.

Easy to use, set up etc and with the light pollution around you will give you as good a view as you'd get with slightly larger instruments. The light buckets are absolutely fantastic - under extreme dark site conditions!

(I've used 8", 10" 13" 18" and 29" Dobbies.....)

I have a C9.25 - excellent scope great on lunar and planets...you can add a x0.63 reducer and still use it visually, BUT if I honestly had to, I mean really had to, chose one scope which I know will be used.....then the 10" Dob would get my vote.

Just my 0.02 euro

[Ben Ritchie]

I am aware that I would need better EPs with the Dob but then again if I get a focal reducer for an SCT at F6.3 it probably won't be that different. I have had both Baader Hyperion and Celestron X Cel LX so far but should I be thinking of better?

Your current eyepieces aren't bad by any means, so I wouldn't rush out and buy anything - people have different tolerances to eyepiece performance, some may find any issues stand out to them and affect their enjoyment of the view, others don't mind at all. It's part of the reason that eyepieces tend to provoke more discussion (and occasionally argument) than any other kit, because fundamentally there are no 'right'/'wrong' answers, just preferences.

So if you find you're happy with your current eyepieces, don't upgrade.

Looks like I definitely under estimated the size and weight of a 14" dob, have seen and looked though a SW 12" only the once so based my thoughts on your choice from that sirmetin.

I was surprised by the 14" too, there's a *much* bigger increase in size/weight (+lack of portability) that you might expect from the progression of smaller Dobs (8->10->12). The 14" is very solidly built - a good thing! - but damn heavy for it.

As a backyard Dob for reasonable/good skies plus the occasional star party it's great, but I would certainly look elsewhere if regular portability was any kind of issue unless I had a large car/van with a flat rear loadspace ... and a willing helper to lift it in/out.

[johninderby]

On the subject of 14" dobs the Orion Optics UK 14" is much, much lighter than the SkyWatcher 14" dob. Hardly any heavier than the 12" SkyWatcher. If you fit carry handles to the tube it's fairly easy to carry for one person, and the alloy OO base is far more compact (about 18" square) and is light enough to carry in one hand. I can carry the 14" OTA in one hand and the base in the other, although normally it's one at a time as you can manoeuvre around obstacles a lot better that way. I use a StellarCAT drive system on my OO 14" which works brilliantly, and if you don't want to use the drives you can just unlock them and use it as a regular push-to dob.

I do like the CPC though and It would be my choice among the ALT-Az SCTs. Pity they don't make the OTA detachable from the forks for transporting though.

John