Celestron C11-S GT XLT GOTO questions

[xarcane]

Hi Everyone

I have been saving for a long time now getting by on my skymaster 20 x 80. but now the time is near to by the scope. I amd thinking about getting this

http://www.firstlightoptics.com/advanced-series-goto/celestron-c11-s-gt-xlt-goto.html

I have read some reviews but I was wondering if any of you have had first hand experience with this model.

A couple of questions too

Is the mount of good quality or should i buy a different mount ?

For istance is a Skywatcher NEQ6 PRO Synscan more stable than a Celestron CG-5 GT GOTO and would the C11 be compatible?

Also

from what I have researched this is an f10 does this hamper DSO imaging too much?

thanks

[RichieP]

I have to say that the C11 looks under mounted on the CG5. I think a scope if that weight and size would be better off on an NEQ6. Especially if you plan on AP.

Should be no problem compatability wise if you get a C11 OTA with a vixen dovetail.

I think many people imaging with this scope use a focal reducer that takes it down to F6.3

[gkec]

I have the 8" version. The CG5 is fine for that but I really would not like to lift a heavier scope onto/off it.

[xarcane]

thanks guys a little bit more saving is in order then

[gkec]

thanks guys a little bit more saving is in order then

The point I was making was not that the mount can't take it. Although RitchieP is of that opinion. which is possibly quite valid. Just that I find heaving the 8" onto to the mount (whatever it is) only just the right side of comfortable

[billhinge]

I bought the older C11 with the CG5 when it was on offer, so effectively the CG5 was free with the OTA

My upgraded C11 is about 33lb (new baader focuser and losmandy dovetail) - it does work with the CG5 but I suggest you change the dovetail as it is a week link

I stripped the mount down totally it is OK for planetary / lunar photo/video but no good for dso photo with the CG5

I now prefer to use the free CG5 with my 80mm APO which works fine,

Buy it and either sell the CG5 and put the money to something bigger or keep it and use the CG5 for something else then save for a new mount

I like the C11 but I think it deserves an observatory mount, I prefer the smaller 80mm for quick easy set up

[rowan46]

I see the c11 is for between 16 and 1800 at other stores so the flo price is a really good deal. the cg5 will just take a c11 but you will not be able to image with it. So I agree with Billhinge buy the package sell the mount and buy an eq6 it should work out a bit cheaper that way

[xarcane]

Yep you guys are confirming my suspicions. so two questions off the back of that.

1. how much would i get for the CG5 mount?

2. or is it cheaper to buy the OAT C11 and then the EQ6?

trying to guage if the pro's and cons,

[MarkSix]

With the new VX mount coming up from Celestron I think you should wait. And hopefully we will get some reviews of this new mount soon.

[xarcane]

With the new VX mount coming up from Celestron I think you should wait. And hopefully we will get some reviews of this new mount soon.

cool probably will wait then

[xarcane]

Also does anyone have an idea of how much FLO sell the C11 OAT for it says Phone for a price on the website

[billhinge]

well they sell the CG5 at £525, a google of C11 OTA etc averages at £1590 and the package is £1789 so you are paying approx £200 for the Cg5

At one time the the OTA by itself and OTA + CG5 were nearly the same price! (crazy astro prices)

PS I know its a risk but I suspect you could get more than £200 for an unopened boxed CG5

PPS - have you asked FLO if they will upgrade the mount if you pay extra - may work out a better deal?

[M4lcs67]

For my two pence worth I bought the 9.25 version last July and to be fair another thing to take into consideration is the handling of such a large ota on and off the mount. The 11" version will be even worse. The 9.25 isn't as powerful, but sometimes you have to take other things into consideration. Not just raw power. Set-up time, cooling down time etc. The 9.25 is regarded as the one to choose anyway and is well up there. I did alot of research before I bought mine and the consensus is that the C9.25 is a brilliant scope.

[MarkSix]

I agree with Malc. I feel that my C9.25 is as far as I would go in size with a portable setup. I feel that my C9.25 is in the verge of being cumbersome sometimes. But I do roadside astronomy so if you do yor stargazing from your garden it might be a different story.

[billhinge]

I agree, bigger isn't always better although tempting, I actually enjoy an 80mm more, the C11 is a big handful by comparison.

I would consider the C11 as a long term investment, better mount and preferably a permanent solution since it is heavy (30lb +) to set up and take inside on a regular basis especially with our weather (I recommend strongly changing the dovetail and get one of those anti slip lock devices, does make setting up easier)

[kirkster501]

The C11 tube though is fabulous. I had one on my CPC1100 and was superb. Their FL is too long though for me personally for what I want to do. I agree also it is a big beast. Make sure you see one before committing the hard earned on it.

[Dunkster]

I'd agree with the sentiment about seeing one before you buy, if you can. But it will be a case of your fitness/strength/whatever to decide which works OK, assuming money isn't a factor. Really like my C11, but also have a C8 for grab and go

[m.tweedy]

I'd agree with the sentiment about seeing one before you buy, if you can. But it will be a case of your fitness/strength/whatever to decide which works OK, assuming money isn't a factor. Really like my C11, but also have a C8 for grab and go

Exactly the same for me C11 fr starparties and the C8 for grab and go

[xarcane]

Hi Guys

Thanks for all the advice but i should of explained my situation first.

Ihave been using bino's for a bout a year now saving for two scopes....one scope is going to be a nice small refractor I can take out and about (i.e. to the astro club) the other C11 in this case will be a fixture in my garden not going anywhere as i am building a obersvatory and live in a dark sky area.

so moving it about should be a problem...the issue is I did want a perm plinth but i thought this may cost more than a strudy tripod.

any thoughts?

btw billhinge thanks for the advice on selling a new CG5

cheers

[billhinge]

thanks for your understanding, trying to help ;-)

C11 is good but it needs a beefy mount to do it justice, true a CG5 will allow you to do some visual with C11 and if you put in the work you can even do lunar and planetary video stacking

But to get the best out of it you will need to spend £££

having said that, look at the the altair range of refractors - eg 80mm APO (or similar - I'm not on commission ;-) - smaller scopes are more fun to use until you get an observatory for a C11 (but of course you may think the c11 a long term investment)

[Dunkster]

NEQ6 would work a treat IMO... handle the C11 (as you're not moving it much) with ease for visual and planetary imaging, and a small refractor for DSO imaging. Then, you can piggy back the refractor on the C11 and get the best of both worlds

[opticalpath]

I think there's another more serious issue. You asked if this being a f/10 scope will hamper your plans to image DSOs ........ the answer is yes, it will. Apart from the adequacy or otherwise of the mount, there are three problems:

1. F/10 is photographically very 'slow', so you will need very long exposures to obtain satisfactory images of faint DSOs

2. The focal length of this scope at f/10 is about 2800 mm. That means a very small field of view (so forget about wide field images), and a highly magnified image that will require extremely good (= expensive) mount tracking and guiding.

3. The FOV is only 'flat' over quite a small area. Cameras with medium to large sensors will produce images with distorted stars away from this small central area.

The combination of long focal length and long exposures makes for the most challenging imaging; not impossible, but very tough indeed. A Celestron 0.63x focal reducer improves matters a bit but is still far from ideal. If it's your first foray into imaging, this really is not the right place to start imo. As Billhinge said above, the C11 would be good for visual use and for high-speed imaging of Moon and bright planets, but it's very far from ideal as a DSO imaging scope unless possibly you're going down the Hyperstar route - which has its own added complexities.

If DSOs are your main imaging interest, I really recommend that you consider a small APO refractor. With a shorter focal length, faster f/ratio and lighter weight, this would be far less demanding on the mount and guiding accuracy and will be much easier for you to get satisfying DSO images with.

I'd also really recommend you invest a few pounds in this book: http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html before you spend the big bucks!

Adrian

[xarcane]

Hi all

thanks for all the help it has given me a lot to think about...opticalpath has answered one of my main concerns about the C11. I really do want o do DSO imaging in the long run and I think i need a good all rounder scope one that can handle our backyard planets and DSO.

By the way i have about £2k to spend on a scope not including a mount to which i am prepared to speand about £1k

thanks again

[vlebo]

I still find it odd the amount of posts I have read about the C11-S GT XLT Goto being undermounted on the CG5 yet it is still sold as a package by many retailers. It must be confusing for many newbies looking to purchase this scope and coming here for advice only to be told how unsuitable the mount is and how much more they have to spend to get the correct mount to carry the weight of the OTA. It does beg the question why sell the package in the first place.

[billhinge]

I suspect given that the price the OTA sells for by itself and the the additional mount being less than the combo of OTA + CG5 it is the minimum they can mount it on for visual and so sell to a price point, perhaps just covering the cost of the mount itself, then knowing that there is chance that the original purchaser may then have to upgrade? Just a guess