Scope for school club with a budget of S$2500

jiahao1986 · Post by **jiahao1986** » Wed May 16, 2007 8:32 pm

Hi folks,

Our school astro club has finally got a grant for a new scope, but only S$2500. Now it's time to decide what scope to buy with this grant.

As S$2500 is a real tight budget, it's kind of hard to make the decision. Our club currently have a 14-year-old *dead* Celestron C8 SCT, a 12-year-old out-of-collimation Celestron C6 Newtonian (even the center spot on the primary mirror is gone...).

1).Taking the two scopes above into account, I think we should get a scope bigger than 6" or equal. At this aperture, it can only be Newtonians or SCTs as far as I can think of. SCTs are more portable than Newtonians but may produce less quality image than Newtonians, however, I'm not sure whether a cheap fast Newtonian would produce satisfactory images. Besides, both designs need constant collimation, especially SCTs can only be collimated by star-testing.(?)

2).Besides, portability is also an important aspect to consider for future astro-trips.

3).Another thing is tracking and GOTO, these are also very useful for club activities. An equitorial GOTO mounts might be hard to use in Singapore and may not be very portable, but can have advantages for astrophotography in the future. Those integrated Alt/Az GOTO mounts with short tube SCTs are more portable, and easier to use, but may not be suitable for future astrophotographic use... However, a Dob might also acceptable considering the aperture...

Considering these (or more) aspects, now as far as I know, the following scopes are within our consideration:

Celestron C8 f/5 Newtonian with CG5 GOTO Mount: US$1019
Celestron Nexstar SE6 SCT: US$999
Celestron C6 SCT with CG5 GOTO Mount: US$999

MEADE SN-8 - 8" f/4 Schmidt-Newtonian with LXD75 GOTO Mount: US$1199

MEADE 12" f/5 Lightbridge Dob (or smaller aperture): <US$999
Orion SkyQuest XT12 IntelliScope (or smaller aperture): <US$979 (must not be portable...)
Celestron 12" f/5 StarHopper Dob (or smaller aperture): <US$849

These are all that I can think of, so could you folks please give some suggestions and give your own reconmmendations? Thanks a million!!!

Clear skies,
Jia Hao

Post by **acc** » Wed May 16, 2007 8:42 pm

My guess is that under the less-than-ideal conditions in a school club (rough handling by newbies, improper setup and care etc), a GOTO scope may not be reliable in the long run. An EQ GOTO mount may even be worse since you need proper and precise balancing etc. But if you really want to buy a GOTO scope, I would go with the Nexstar SE6. Its drive mechanism is robust and you can mount other (small) OTAs on the mount using a dovetail.

My first choice would be the Meade 12" Dob though... Seems to have excellent optics (various reviews on the web), will have better image quality than equivalent SCT, big aperture, won't break-down, easy-to-use, relatively portable, easy to clean and maintain, and no fungus issues.

The other solid-wall dobs are out as portability is an issue (though a 10" dob can fit into most mid-size sedans)

jiahao1986 · Post by **jiahao1986** » Wed May 16, 2007 9:47 pm

Thanks acc for your advice, hope other folks could kindly give their suggestions too.

kayheem · Post by **kayheem** » Wed May 16, 2007 10:48 pm

I would go with acc to discourage a GOTO. Instead, I would recommend the 8" or 10" Meade Lightbridge with Digital Setting Circles (DSC) and a tracking platform. This combo will give:
1) adequate aperture
2) push-to object location
3) tracking to enable more ppl to look at it without shifting around
4) much less things to break down.

mrngbss · Post by **mrngbss** » Wed May 16, 2007 10:58 pm

At your (university) level, I think a GOTO system would be able suitable for your club as a new scope. Your members already know the basics and thus to be able to explore into the unknown of GOTO, computer control and astrophotography would be like adding spice to what you have.

in my opinion, students/newbies would always contribute to the mishandling of scopes, no matter how much instructions and reminders (even fear) you give them.

I'm also for students being able to have different experiences with different scopes. This will broaden their perspectives and allow them to understand what people are saying about astronomy and equipment.

For S$2500, it is little but can still make full use of it.

Cheers!

river · Post by **river** » Thu May 17, 2007 10:41 am

Nexstar 6SE + red dot finder + a better diagonal + a dew remover + hard case.

reason:

1) minimum part count = less chances that a small part will go missing after each session and it is easy to pack

2) simple and light structure design, easy to setup and use. Easy to bring around.

3) GOTO - a must since clear sky is limited and you have to save some time. short learning curve for new student.

4) Can convert to GEM with the wedge tripod for imaging

5) PC connectivity with good online resources.

Canopus Lim · Post by **Canopus Lim** » Thu May 17, 2007 10:45 am

Perhaps a dob is not a good idea since it needs collimation frequently. Unless the people are trained to do the collimation well. Also, the dob being much larger in size may be a hindrance in carrying onto boats like trips to Tioman, Redang etc.

Prob the Nextsar 6SE is a better solution.

kayheem · Post by **kayheem** » Thu May 17, 2007 11:25 am

I guess it all boils down to the experience of the club members and also what they want to see.

IMHO, 8" will allow them to see more and will still be fairly portable. jiahao, it's your call.

river · Post by **river** » Thu May 17, 2007 12:06 pm

is it possible to reuse part of the old C8 and re-collimate the 6" New?

If you can save the two OTA, another option is to buy a tracking mount, GOTO or not that can support both OTA. That give your club an imaging platform for some advance user.

The balance can buy a Dob (DIY kit is cheaper) and/or Bino.

jiahao1986 · Post by **jiahao1986** » Thu May 17, 2007 12:27 pm

First thanks folks for all the advice. We sent the C8 to Science Center just recently, but it returned unfixed, now the field of view through the C8 is a cigar or spindle like shape (they must have glued the secondary off-centered...), and still out of collimation. For the C6, we are trying to collimate it recently, but I doubt it will keep the collimation even if we collimate it as the focuser is quite special as it adjusts the secondary mirror to achieve focus and it is also in bad condition.

It's really hard to decide now, whether to say goodbye to those two old scopes or try save and reuse them (though the hope is little)...