Should I change scopes? Need help...

[Mr. Subatomic]

Hi everyone,

For about a year now I have owned a 10" Dobsonian telescope bought from Bintel in Sydney. There is nothing wrong with the scope, it is a superb scope, but it is my circumstances that are the problem. I often find that I don't get much time for amateur astronomy, and when I do I have a difficult setup in a confined urban environment with significant light pollution.

As a solution I've been considering selling the scope + some of the accessories and using the money to purchase a smaller, simpler, more manageable computerised Go-To telescope, such as the Celestron Nexstar 114 SLT reflector.

Could anyone provide their opinion on this kind of change? Do people often make these changes to smaller telescopes?

Thanks for your help!

[h0ughy (David)]

I think that you have a plonk and go scope as it is with a 10" dob - how hard is it to just go out, plonk it down (maybe collimate )then go for it amd find stuff. if not then get yourself a pair of 25 * 100 binos and a bino mount for a true plonk and go setup. your wasting your time with the 114.

[Starkler (Geoff)]

A few years ago I had just a 10 inch and decided to downsize to something smaller and bought an ed80 refractor.

In short i was disappointed in how little I could see after being used to the views through a 10" scope, and light pollution just makes this worse. At least with a larger scope you can crank up the power before running out of light.
Luckily I kept the 10" and ended up selling the ed80, replacing it with a 5" newt on a porta alt-az mount, which serves as my travel and quick look scope.

Bottom line is i think you will be disappointed unless you can see the difference for yourself and then decide after. If space is an issue, maybe an 8" lx90 or similar might suit?

[csb (Craig)]

I had a similar problem with a smaller 150mm newtonian. My house has three levels at the back (so 2 sets of stairs). Of course the lowest/last level was the most light shielded and negotiating that with Newt and gear was a drag.

I got a 150mm sct instead - a lot easier to handle.

So, fellas, it can be more than how quickly a scope can be set up.

I have read some reviews of Celestron 114 and perhaps you will be dissapointed. They look cheap in the store.

Perhaps consider :

150mm SCT - shorter than a newtonian

100mm refractor - they tend to have better contrast then Newts - although I'm not sure with light polluted sky.

Intes MK-65 Maksutov is for sale in the classifieds (these get good reviews)

http://www.iceinspace.com.au/forum/s...ad.php?t=26046

[goober (Doug)]

Originally Posted by Mr. Subatomic

Could anyone provide their opinion on this kind of change? Do people often make these changes to smaller telescopes?

Thanks for your help!

Mr. Subatomic, I did this mid-year and haven't looked back. I went from a 8" dob to 12" dob - good scope (sort of), but just wasn't using it. I got to use a 4" refractor for a month and realised that was the scope for me. So yes, I've changed to a smaller scope, and love it. It gets me out there 2-3 times a week, rather than 2-3 times a month.

[DJVege]

It sounds like you have difficulty finding objects due to the light pollution. Instead of selling, why not spend some money on the Argo Navis? It's not cheap at just over $1000 all up, but it will make finding objects much easier.

I only have a 5" scope, and I'm already dreaming about an upgrade to more aperture! Thank Phil and his 16" LB for that!!!!!

Just a suggestion.

[g__day (Matthew)]

That last bit of advice is well reasoned, the further you identify your needs and wants - the better advice you will receive.

Light pollution I would imagine is a lesser problem for a large scope - because on narrowfield work its signal to noise ratio (gathering and magnification of light from stars versus light from dust in sky) will be better than a smaller scope.

So if its setup or time optimisation you require with any rig to make the most of your circumstance you need to see what can be done.

Unless you have a permanent observatory and/or a permanent pier for a GE mount - set up will always take time - even for visual. If you go into astro imaging - set up will take a whole lot more time!

About all you can do is get help carting and porting your gear for set-up!

To optimise your time viewing - plan your targets ahead of time - during the day say using Cartes Du Ciel so chose 4 targets from 8-9pm or 5 from 9pm - 10pm etc and work out what eye pieces will likely give you best results. As per DJVege's suggest Argo Navis seems wonderful - and will making finding DSOs a breeze!

Good luck!

[PhilW]

Not sure if you are into building things, but here's a thought. I found my 10" sonotube dob just too cumbersome and heavy to haul around, seeing as I am a self-confessed wimp. So I rebuilt it as a super-light truss (see pic). That blue stuff is just foam board with glass resin over it. So the whole thing could be carried out in one trip, and moved around easily. Only downside is its tendency to blow around in a high wind since it so light.

If $1K for the Argo is too steep for you (it is a superb product btw, & a great idea), you can always go the low-end route with alt-az setting circles, in conjunction with a program like Cartes du Ciel. There's a forum article on doing this.

And yes, it should ultimately be driven by your observing objectives. If you are interested in deep-sky observing, I find it hard to imagine you'd be happy with less aperture than you have now.

Oh, one note to avoid confusion: that mirror box in my avatar pic was the one I built for my subsequent 14" (same technique though). I doubt I could fit my son into the 10" without protest.

Phil

[Mr. Subatomic]

Digital Setting Circles do sound like a great option, though I'm not sure I want to spend over 1K on Argo Navis, despite the fact that it is the best in its class.

I would happy to settle with SkyCommander DSC's. Does anyone know how much they go for, or if there are other companies that make these products?

Thanks for your help.

[Gerald Sargent]

I have a set of gears to fit a losmandy with encoders
and the Sky Commander controller, it is for sale if you
are interested, Gerald.

[gary]

Originally Posted by Mr. Subatomic

Digital Setting Circles do sound like a great option, though I'm not sure I want to spend over 1K on Argo Navis, despite the fact that it is the best in its class.

Hi Mischa,

Gary Kopff here from Wildcard Innovations, manufacturers of the Argo Navis
DTC.

An Argo Navis solution for your scope can be purchased currently for A$877.90
delivered. This includes 10,000 step high rsolution optical encoders and the
encoder mount hardware and encoder cable.

Argo Navis DTC is designed and manufactured here in Sydney. Unlike the older
DSC units manufactured in other parts of the world, they have an Australia/New
Zealand C-Tick rating which makes them legal to use in Australia. Should
you ever export it, it also can be legally re-imported as it has approval.

Argo Navis is a Digital Telescope Computer (DTC) not a Digital Setting
Circle (DSC). This is an important distinction. Whereas DSC's, like their
mechanical setting circle counterparts, have no way for compensating for
the various systematic fabrication errors within the mount/OTA, an Argo Navis
DTC can analyse and potentially compensate for many of the more common
fabrication errors. The ability of a pointing solution to reliably locate
and identify objects is its most important attribute.

Should you migrate to a different scope in the future, such as a larger
aperture Dob, there is a good chance you can port your Argo Navis and
encoders to it.

Hope the above information is helpful.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

[Peter Ward]

My usual mantra I know, but sometimes you just gotta get over the price, and accept some products are built to a specification.

I have no commercial links with Gary's product but, like Sellys' it just *works* ..the surface mount PCB electronics are beautifully laid out...giving the impression of a quality product that will give many, many years of service.

Originally Posted by gary

An Argo Navis solution for your scope can be purchased currently for A$877.90
delivered. This includes 10,000 step high rsolution optical encoders and the
encoder mount hardware and encoder cable.

[gbeal]

Don't do it. I have a cracker 10" newt, and have tried smaller scopes, always with disappointment. One of these was a very high priced, and well made 4" apo. Yes it looked nice, but the 10" at a fraction of the cost simply blew it away.
I too have no affiliation whatsoever with Wildcard but this is where I would be looking as well. It is money well spent, and like a decent eyepiece isn't necessarily tied to the current scope, it will be something you keep and use forever, on subsequent scopes.

[Prickly]

Hi,

I have a 4 inch refractor. I agree a 4 inch refractor might be disappointing for suburban viewing especially after using a 10 inch. Mine 4 inch is a good achromat - a vixen. Good in country skies (amazing what you can see) but I reckon you need a bit more aperture in the burbs to pick out deep sky objects. For planets when you get to high mag (375x on a good night -maybe this exceeds the rule of 50x per inch but it seemed to work) the images were just getting a bit dark - therefore aperture again is needed.

If portability is the issue then a more compact scope SCT or maksutov may be the shot. 8 inches has long been the popular choice for balance of portability of weight and aperture. Also theres the GSO 8 inch f4 which might be pretty light and compact (not sure here) and the skywatcher 7 inch mak (just a tad under 8 inches).

If computer pointing is the main issue then an argonavis would be a great bit of kit. I dont own one and also have no affiliation with Gary except that he did show me the unit once and in my opinion it looked great. I was very impressed that you could filter objects by magnitude (perhaps other things too) and have tours. This would be very nice for light polluted suburbia. To me it looked very robust and I have a friend who loves his.

Good luck with your choice.

David.

[Mr. Subatomic]

If I did opt for a different scope it would involve selling my current 10" Dob and buying a different type of scope with the money from the sale (maybe $600-$700, I'm only 16 so I don't have all that much money). That probably rules out the larger apeture SCTs or maksutovs.

I;m on school holidays at the moment so I guess I should get the most out of my 10", see what it's really made of.

By the sounds of it I probably won't be finding a second Argo Navis, I doubt anyone would want to let go of one and I don't blame them.

Thanks for your help.