Jump to content


Photo

7-9,5 Inch Telescopes for DSO Imaging?

  • Please log in to reply
60 replies to this topic

#51 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 22 August 2014 - 03:33 PM

The only advantage I see for the CF tube is better isolation from unwanted external light sources along with the baffling. The truss design can also do this with a shroud or lightweight liner.

 

Both have the focusers attached to the mirror cell, but maybe the serurrier design handles the sag.

 

The truss design has a dovetail half the length of the CF tube model. The aluminium dovetail's high thermal coefficent undoes some of the CF thermal advantage, so the shorter dovetail of the truss should be impacted only half as much.

 

Gale

 

I am asking that because I am considering buying an AT10RCT right away, so that it will be the AP telescope that will suit me for a lifetime. It is short enough. 



#52 Eddgie

Eddgie

    Voyager 1

  • *****
  • Posts: 13183
  • Joined: 01 Feb 2006

Posted 23 August 2014 - 08:17 AM

The benefit of carbon fiber (according to marketing literature used by Celestron years ago when thy sold CF tubed scopes) was that it would not expand and contract during a very long exposure resulting in defocus.

 

I doubt that there is any thermal management benefit.   The mirror boundry laywer was, is, and always will be the chief issue for thermal managment in reflectors.  The kind of tube will not make nearly as much difference as the cooling of the primary mirror itself and as long as the tube is properly over-sized for the primary, there is not much to be gained by using carbon fiber in terms of thermal management.



#53 Karthik

Karthik

    Explorer 1

  • *****
  • Posts: 54
  • Joined: 07 Nov 2008
  • Loc: Erie, PA

Posted 23 August 2014 - 09:08 AM

The thing about Astrophotography, you need to spend 60% of your budget on an exceptionally good mount, the rest can depend on what you wish to accomplish. I would start with a good mount that you can transport to the site and back, work your way up from there.


Edited by Karthik, 23 August 2014 - 09:10 AM.


#54 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 23 August 2014 - 03:59 PM

The thing about Astrophotography, you need to spend 60% of your budget on an exceptionally good mount, the rest can depend on what you wish to accomplish. I would start with a good mount that you can transport to the site and back, work your way up from there.

 

Well, I think I have decided to get an AT6RC (400$) and an iOptron CEM60 mount (about 3000$) so... yeah.I know that the CEM60 is almost an overkill for the tiny 6" tube, but it will be good enough for an upgrade.



#55 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 23 August 2014 - 04:01 PM

Also, I think that this thread is very good for anybody considering starting AP and buying am SCT-like scope. 



#56 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 23 August 2014 - 04:09 PM

I think the best solution would be to buy the AT6RC (extremely portable and cheap, withless than top notch but satisfying performance) and consider the AT10RC or something like that as a future upgrade.



#57 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5719
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 24 August 2014 - 12:56 AM

The AT6RC is slow.  f/9 means you'll be twiddling your thumbs for a long time.  Best to get the AP CCDT67 to reduce it.



#58 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 24 August 2014 - 03:28 AM

The AT6RC is slow.  f/9 means you'll be twiddling your thumbs for a long time.  Best to get the AP CCDT67 to reduce it.

 

Yeah, that is what I thought.



#59 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 24 August 2014 - 03:59 AM

How well will I be able to use the AT10RC with the iOptron iEQ45 for AP? I am considering it as a cheaper alternative to the CEM60.



#60 Karthik

Karthik

    Explorer 1

  • *****
  • Posts: 54
  • Joined: 07 Nov 2008
  • Loc: Erie, PA

Posted 24 August 2014 - 08:27 AM

 

The thing about Astrophotography, you need to spend 60% of your budget on an exceptionally good mount, the rest can depend on what you wish to accomplish. I would start with a good mount that you can transport to the site and back, work your way up from there.

 

Well, I think I have decided to get an AT6RC (400$) and an iOptron CEM60 mount (about 3000$) so... yeah.I know that the CEM60 is almost an overkill for the tiny 6" tube, but it will be good enough for an upgrade.

 

That is a good combination, are you getting the CE60-EC? I have been following this thread in hopes of starting astrophotography in the future, good information.

 

my2cents: I still think a small refractor will be better than the AT6RC, you will reduce frustration with collimation issues and the learning curve will not be too bad. Plus, you will get used to the mount. 


Edited by Karthik, 24 August 2014 - 10:40 AM.


#61 AFScienceTime

AFScienceTime

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 15 Jun 2014

Posted 24 August 2014 - 04:20 PM

 

 

The thing about Astrophotography, you need to spend 60% of your budget on an exceptionally good mount, the rest can depend on what you wish to accomplish. I would start with a good mount that you can transport to the site and back, work your way up from there.

 

Well, I think I have decided to get an AT6RC (400$) and an iOptron CEM60 mount (about 3000$) so... yeah.I know that the CEM60 is almost an overkill for the tiny 6" tube, but it will be good enough for an upgrade.

 

That is a good combination, are you getting the CE60-EC? I have been following this thread in hopes of starting astrophotography in the future, good information.

 

my2cents: I still think a small refractor will be better than the AT6RC, you will reduce frustration with collimation issues and the learning curve will not be too bad. Plus, you will get used to the mount. 

 

 

Well,I thought that a small, decent APO would be much more expensive and wouldn't have a large enough focal length, not to mention it wouldn't be as portable (very few telescopes are as portable as the AT6RC for me, as short=portable).

 

Also, I am getting the CEM 60 standard version (non-EC), since the encoders are shut down when using an autoguider, and I intend to use an autoguider. Anyway, it is much more expensive. I am actually also considering the iEQ25, but I don't know if it will work with the AT10RC, which I am considering as a future upgrade.








Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics