Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

If Money didn't matter what would you prefer

  • Please log in to reply
51 replies to this topic

#1 jjbag

jjbag

    Viking 1

  • -----
  • topic starter
  • Posts: 534
  • Joined: 28 Feb 2017
  • Loc: Mid Atlantic

Posted 19 February 2021 - 01:39 PM

So I have a question if could choose between the following types of Telescope (regardless of cost) for general usage which would you choose and why.

 

14" Premium Dob   F4.5

 

or 

 

14" Advanced Coma Free F/10 or F/8

 

Just curious since they are roughly the same price though with Goto the premium dobs are a bit more... but i'm not choosing by price, i've only have visual with Dobs other than my small etx 80. 


Edited by jjbag, 19 February 2021 - 01:43 PM.


#2 Supernova74

Supernova74

    Surveyor 1

  • -----
  • Posts: 1,781
  • Joined: 25 May 2020
  • Loc: Epsom surrey near (London)

Posted 19 February 2021 - 01:43 PM

the Meade all day long 


  • Foundationer likes this

#3 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • Posts: 10,681
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 19 February 2021 - 01:45 PM

14" premium Dob since it would actually be portable and have decent optics.


  • scotsman328i, Allan Wade and GUS.K like this

#4 carver2011

carver2011

    Ranger 4

  • -----
  • Posts: 332
  • Joined: 07 Aug 2011

Posted 19 February 2021 - 01:50 PM

This is what I would get.

Takahashi Mewlon M-300CRS f/9.9 Dall-Kirkham Cassegrain
 Regards

   Ed


  • nemo129, Codbear, jjbag and 1 other like this

#5 CoHPhasor

CoHPhasor

    Messenger

  • *****
  • Posts: 444
  • Joined: 04 Mar 2016
  • Loc: San Francisco, CA

Posted 19 February 2021 - 01:51 PM

I don't know.
One of the things that stands out for me on Dobs is the placement for the EP.
All the way at the top? It varies so wildy if you want to look at objects at different places in the sky during the same night.
It's also kind of weird to have to wrap the scope so light doesn't get in.

 

  Beyond that, I don't have physical experience with dobs, especially large ones.

A 14" SCT would be a beast, no doubt, as my 11 is a little hefty.
At the same time, the SCT on a GEM still breaks down, just into heavier pieces.



#6 junomike

junomike

    ISS

  • *****
  • Moderators
  • Posts: 21,385
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 19 February 2021 - 01:53 PM

Dob for me simply for the easier set up (IMO/IME) and wider FOV.


  • scotsman328i likes this

#7 BWAZ

BWAZ

    Surveyor 1

  • *****
  • Posts: 1,555
  • Joined: 21 Nov 2005
  • Loc: San Diego, CA

Posted 19 February 2021 - 01:55 PM

It really depends one's observing preference, habit, environment and etc.

 

As for someone like me stuck in my backyard, either can be good but neither is perfect. That said, I'd give a slight edge to the 14.5" premium Dob for what I do and how I do. 


  • bobzeq25 likes this

#8 Stellar1

Stellar1

    Apollo

  • -----
  • Posts: 1,192
  • Joined: 08 Dec 2018
  • Loc: Ontario, Canada

Posted 19 February 2021 - 01:55 PM

Dob here also, just try move that 14" ACF around unless it is permanently mounted.


Edited by Stellar1, 19 February 2021 - 01:56 PM.

  • scotsman328i likes this

#9 jjbag

jjbag

    Viking 1

  • -----
  • topic starter
  • Posts: 534
  • Joined: 28 Feb 2017
  • Loc: Mid Atlantic

Posted 19 February 2021 - 01:56 PM

14" premium Dob since it would actually be portable and have decent optics.

I live at basically a dark site, darker than anywhere near me for about 200 miles , i'm in a 4 so on east coast thats as best you gonna get.. lol 


  • weis14, blakestree and CoHPhasor like this

#10 jjbag

jjbag

    Viking 1

  • -----
  • topic starter
  • Posts: 534
  • Joined: 28 Feb 2017
  • Loc: Mid Atlantic

Posted 19 February 2021 - 02:01 PM

Dob here also, just try move that 14" ACF around unless it is permanently mounted.

Back yard has patio and walkways I was thinking the Meade would be easy on the those trolley they sell and roll it out from garage on patio paths onto the patio in center of back yard. Thinking I need to hit a star party and get some visuals for comparing.. I barely remember the big ones i looked through on Hawaii 3 years later.. 



#11 Doug Culbertson

Doug Culbertson

    Cosmos

  • *****
  • Posts: 8,512
  • Joined: 06 Jan 2005
  • Loc: N. Florida

Posted 19 February 2021 - 02:43 PM

14.5” f/4.2 premium dob, since that’s what I have already.  I’m not a big fan of SCTs, no matter how they dress them up. I also live under a Bortle 4.5 sky, at least when it’s clear. 


  • Jon Isaacs, scotsman328i, havasman and 3 others like this

#12 blakestree

blakestree

    Ranger 4

  • *****
  • Posts: 319
  • Joined: 26 Aug 2011
  • Loc: Savannah, GA

Posted 19 February 2021 - 02:50 PM

I live at basically a dark site, darker than anywhere near me for about 200 miles

That answers your question for you, 14" f4.5 Dob.


  • scotsman328i and havasman like this

#13 harbinjer

harbinjer

    Viking 1

  • *****
  • Posts: 667
  • Joined: 17 Dec 2008
  • Loc: Southeastern Minnesota

Posted 19 February 2021 - 03:08 PM

Back yard has patio and walkways I was thinking the Meade would be easy on the those trolley they sell and roll it out from garage on patio paths onto the patio in center of back yard. Thinking I need to hit a star party and get some visuals for comparing.. I barely remember the big ones i looked through on Hawaii 3 years later.. 

With a rolling trolley, it sounds like for everyday use, you'd be fine with either. Do you plan to take it to a star party ever? For that I think the dob would be much easier, as it breaks down smaller, and into smaller pieces, that  one person can re-assemble. 

 

If this is a long-term scope do you have the eyepieces for it already? The F4.5 dob will be more demanding on eyepieces, but will be more versatile with wider fields, if you want that. 

 

How do you feel about head position? The dob will move a lot depending on your view, but the ACF will be much less motion. 

 

As a long term scope, I feel dobs are more maintainable: you can fix almost any part, or upgrade almost any part independently. The bulk of it's value is in one piece: the mirror.  An ACF has to match a mirror and corrector and neither is useful without the other, and the corrector is quite fragile.

 

Personally, I'd go for the dob. 


  • scotsman328i likes this

#14 alphatripleplus

alphatripleplus

    World Controller

  • *****
  • Moderators
  • Posts: 121,758
  • Joined: 09 Mar 2012
  • Loc: Georgia

Posted 19 February 2021 - 06:07 PM

The premium Dob - it it came with a super GOTO tracking platform. 


  • scotsman328i and Dave Ponder like this

#15 SonnyE

SonnyE

    Mercury-Atlas

  • -----
  • Posts: 2,984
  • Joined: 01 Nov 2015
  • Loc: Cali for ni a

Posted 19 February 2021 - 06:18 PM

I'd ask what you want out of it?

Visual? Imaging?

I always advise folks decide what they want to do, then research what it takes to arrive there.


  • Jon Isaacs, havasman and mrsjeff like this

#16 jjbag

jjbag

    Viking 1

  • -----
  • topic starter
  • Posts: 534
  • Joined: 28 Feb 2017
  • Loc: Mid Atlantic

Posted 19 February 2021 - 07:46 PM

I'd ask what you want out of it?

Visual? Imaging?

I always advise folks decide what they want to do, then research what it takes to arrive there.

Simple Visual with a tad planetary imaging (I have a generic imx224 USB astronomical telescope camera, that i hardly use), I currently use a XT10i dob and the etx 80 (which I use the camera with) so as i slow down in life (aka, can afford things and not worried about college tuition for kids).... I want to upgrade soon (by that i mean within a  year) Was going to last year but became ill. I stand 5'5" so I'm limiting my self to the 14" (for the Meade due to price can get one for under 8k, but I noticed the premium dobs with a go to even the 14/15" push the 10k boundry. I've seen the Skywatcher 14"goto for under 3k but am unsure of the quality of the image compared to the other 2 I'm thinking on. (i know my wife would be happy if i went with the Skywatcher, lol)  but (grins) not her choice.. Anyways that's my thinking and what I plan on doing with it. 


  • SonnyE likes this

#17 GUS.K

GUS.K

    Viking 1

  • -----
  • Posts: 840
  • Joined: 13 Aug 2014
  • Loc: Katoomba, NSW, Australia.

Posted 19 February 2021 - 08:25 PM

For purely visual, the premium dob all the way.


  • scotsman328i likes this

#18 JMW

JMW

    Skylab

  • -----
  • Posts: 4,413
  • Joined: 11 Feb 2007
  • Loc: Nevada

Posted 19 February 2021 - 11:03 PM

I have a 14.5 inch Dob with f/4.3 Zambuto mirror. I consider it large but manageable if I can leave it setup for multiple nights. I have a C11 Edge HD and I use it less for visual and more for f/7 or f/2 imaging. The mount for a 14 inch SCT adds substantially to the setup hassle and total cost. I prefer the wider fields of the Dob.


  • scotsman328i likes this

#19 sanbai

sanbai

    Viking 1

  • *****
  • Posts: 873
  • Joined: 18 May 2019
  • Loc: Baton Rouge, LA

Posted 19 February 2021 - 11:47 PM

I can't report yet my experience with a dob. But the (flater and) wider fields, and large exit pupils with large AFoVs are very compelling.
The dob can show about 4 times more sky area than the SCT.
With premium optics you know what you get. More likely to get a less than stellar in SCTs. Also, cool down time in the premium dobs are shorter, which is nice for planets.
If you want to image planets, get an equatorial platform. You can leave it aside if you don't want to use it. The platform is less expensive than ServoCat, and is equatorial. Add Nexus DSC and you are set.
  • scotsman328i likes this

#20 base16

base16

    Explorer 1

  • *****
  • Posts: 71
  • Joined: 30 Jul 2020
  • Loc: North California

Posted 20 February 2021 - 12:09 AM

If cost (money) is not a concern, I'd go with a good 6" refractor and add night vision/intensifiers for deep sky, and a barlow for planetary; put this on an equatorial mount that doesn't need counterweights (RST or hobym). No collimation, less sensitive to thermal variations compared to mirror based scopes, no spider vanes, and easy to transport anywhere including every day use.

 

 

If cost, where cost is both money _and_ time, are not a concern -- then I'd buy the largest dob I could use.


  • scotsman328i and doctordub like this

#21 Allan Wade

Allan Wade

    Aurora

  • *****
  • Posts: 4,961
  • Joined: 27 Jan 2013
  • Loc: Newcastle, Australia

Posted 20 February 2021 - 12:17 AM

If you look at the strengths and weaknesses of each scope, and then match them to what you want to achieve, you’ll get your answer. Bare in mind we are considering 14” SCT’s and Dobs specifically.

 

I would list planetary imaging as a strength for the SCT compared to the Dob. Then I would list everything else you ever want to achieve in astronomy as a strength for the dob. I hope that narrows down your decision.


  • Jon Isaacs likes this

#22 Redbetter

Redbetter

    Voyager 1

  • *****
  • Posts: 10,496
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 20 February 2021 - 02:45 AM

The Dob, and by a long shot.  I would probably opt for a 16" rather than a 14.5, unless there was some limitation that made the 14.5 preferable.    I have been keeping the option of ~16" Dob in the back of my mind in case a situation arises where I am unable or unwilling to port my 20" out to dark sites, or if I want to keep one large scope in one location, and a slight smaller one somewhere else.  

 

I know that there are good 14" SCT's out there, but I haven't had the opportunity to look through them.  My views through large SCT's have been underwhelming, although most of those impressions were decades old.  The large secondary obstruction has some noticeable impact on visual planetary contrast (as well as some other general contrast reduction.)  The secondary linear obstruction ratio can be considerably smaller in a big Dob--my 20" f/5 runs a negligible ~16% while a 14" f/8 ACF is a substantial 37%.   

 

I would pay careful attention to how you would manage thermal equilibration of a big SCT in whatever conditions you plan to store and use it.  Generally, I find cooling fans on the Dobs handle this well.  


  • scotsman328i likes this

#23 jjbag

jjbag

    Viking 1

  • -----
  • topic starter
  • Posts: 534
  • Joined: 28 Feb 2017
  • Loc: Mid Atlantic

Posted 20 February 2021 - 06:54 AM

The Dob, and by a long shot.  I would probably opt for a 16" rather than a 14.5, unless there was some limitation that made the 14.5 preferable.  

I stand 5'5" so I'm finding the 16" one zenith eyepiece height would require a small step ladder, not sure I want to be standing on a step out in the dark to view. 


  • Stellar1 likes this

#24 WadeH237

WadeH237

    Fly Me to the Moon

  • *****
  • Posts: 6,917
  • Joined: 24 Feb 2007
  • Loc: Ellensburg, WA

Posted 20 February 2021 - 09:43 AM

In the context of the question, I have to assume that we are talking about visual use.

 

In that case, it is no contest at all.  I'd take the Dob all night long.  I already have both a 14" SCT and a 14" Dob.  They provide very different observing experiences.  The C14 wins for planetary and very high magnfication, solely due to being on a tracking mount.  The Dob wins for ease of setup and ease of use, and provides more flexibility for DSOs, since it can support much wider fields than the C14.  My Dob is F/4.6, and with a 31 Nagler and Paracorr, it can just frame M31 and friends.  That view at a dark sky site is nothing short of spectacular.

 

I am recently retired, and primarily an imager.  My first order of astronomy business (after completing some non-astro construction projects on my property) will be to build a 20x10 observatory with two piers.  One pier will hold my imaging setup, which will likely be an AP1600 mount carrying an AP130 GTX most of the time, with a bigger scope mounted for galaxy season.  The other pier will be an AP1100 mount carrying the C14 for visual use.

 

Once the observatory is complete, I will start thinking about a new Dobsonian for visual use at star parties.  My son will be taking the current 14" Dob, so I'll build a new one.  It will probably be somewhere between 15" and 20".  I am limited by the eyepiece height at the zenith, so it will need a fast mirror.  My wife has said that I cannot build a scope where she needs to get off the ground to use it.  I'll set it up with the best mirror I can source, and a Nexus DSC system for push-to (I don't need tracking for the way that I usually observe with the Dob).


  • Allan Wade likes this

#25 SloMoe

SloMoe

    Soyuz

  • *****
  • Posts: 3,856
  • Joined: 23 Dec 2016
  • Loc: Washington State

Posted 20 February 2021 - 10:00 AM

If money didn't matter,,,,,,,,

 

Hubble, it's already set up for imaging, no need to go visual, sit in my living room and stream it to my wide screen,,,,,,,,


  • SonnyE, CoHPhasor and jjbag like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics