Which Telescope do i get ?

[Guest Darrian]

Hi guys

As i mentioned in an earlier post the motor on my Celestron 102gt packed up and i decided to return the scope and put the money towards somthing bigger.

I have been looking around and would like somthing thats either 8" 10" 12" , It has to be GOTO and it has to be good for Astophotograpy and good for Deep sky , got about £1300 to spend so should be enough

But thats where i get stuck because it is just a minefield out there !!

I was looking at DOBS and quite fancy the Skyliner 300P Flex Tube SynScan GOTO, as it would be great for DSO but how do the perform with Astophotography ?

I was also looking at the Celestron Advanced C8 S-GT XLT , Now i know this will be ok for pics and stuff but i loose 4" in aperture and i may stuggle with Dso ....

Now do i sacrifice Aperture for electronics or do i just buy big because its better ....?

Any comments welcome

Darrian

[catman161]

Hey Darrian,

As you know I am fairly new to this myself but something I have picked up on is "go large". The bigger the aperture the more light gathering capacity you have and the better/more you can see. When it comes to the motorised goto side of things I will let the 'proper astronomers' on here guide you as I am blissfully ignorant at the moment but hopefully the more I do this the more I will learn

Felix

[Guest Tweedledum]

Hi Darrian,

I will let one of the Imaging maestros pick up on that front, but unless you already have the imaging gear you are going to struggle on your budget .

Felix says go large, but you then need something super stable to mount it on and although you can image off an sct quite successfully it aint easy. I have a 10" sct the tube & forks weigh 70lb and the tripod 30 odd...

So if goto is important you would probably need a HEQ5 pro £747, that leaves £500 for the tube, ep's imaging gear...

If you are starting out, walk first then run, Felix above has the 200p dob that is a great scope to start your journey, you can always sell on and then get your imaging kit. Caveat Emptor!(Let The buyer beware...)

[Rusty Strings]

The only problem with trying reconcile large aperture for visual and mount stability for astro imaging is that is really can't be done. Imagers generally use small scopes on an HEQ5 or more usually, an EQ6. Because astro imaging uses long exposures the aperture isn't as crucial. There are those that do planetary imaging with a dob but I would suspect that if they had their time again, they would chose a different set up.

[+Ibbo]

For astroimaging I would go ED80 EQ6 and a DSLR

the mount will allow you to expand somewhat as you imaging skills improve

for visual as big a dob as you can afford/carry

[Guest NadeemShah]

I would have to agree with Steve, you really can't beat an ed80 with a dslr with a EQ6, at least when you upgrade, you will not need to worry about buying a bigger mount...

Just think about it, no collimation needed, less cool time, longer subs with a less focal length...

Edited February 6, 2012 by NadeemShah

[Doc]

It's simple small APO for imaging or a big dob for observing, they are two different scopes for two different jobs.

[red dwalf]

as said above, they are different scopes for different things,

with your budget have you considered second hand items, £500 for a second hand heq5, £300 for a 70-80mm imaging scope leaving £500 for your camera, either a dlsr or a ccd camera, maybe a small chip atik and if it`s mono maybe some filters too.

[Brantuk]

Dobs are basically Alt/Az mounts and wether motorised or not you will get star trailing on long exposures - it's unavoidable on this mount type and you really need a beefy Equatorial mount wich can be polar aligned and will track in a single plane (RA) only. That way the Earth moves the scope for you and eliminates star trailing.

For greater accuracy over thousands of light years - most imagers add guiding - second scope and camera that feeds back any necessary adjustments to the mount to keep it on target, by simultaneously tracking a point source like a star nearby to the object. The tool of choice for this is a good quality refractor with a wide field of view and appochromatic objective (doublet or triplet). These are very nice for capturing larger objects like galaxies and nebulea.

An EQ6 mount would handle a fast newtonian (f5 or less) with up to an 8" or possibly 10" aperture - also nice for imaging dso's and gives a good observing platform too. Quite a useful combination - you just have to deal with coma inherent in the optics (otherwise figured out and corrected in appos).

Just for observing though - as big a dob as you can handle is the preferred choice.