derekdann30
member
Reged: 02/26/10
Loc: Elizabeth City, North Carolin...
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thoughts on the 12.5 Obsession
#5701345 - 02/26/13 10:27 AM
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Hi there. I've been into visual astronomy now for almost twenty yrs. I currently have an Orion XT8 which I think is a fine scope. I was originally thinking about having a small grab n go refractor to compliment my dob. I just recently decided to go the other way in aperture and is considering the 12.5 inch Obsession. I've always been fascinated with the truss tube designs. Would the image quality and brightness be a big jump from an 8 inch? How would this compare to the truss scopes from Orion and Meade? Thnx
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Astrojensen
Post Laureate
   
Reged: 10/05/08
Loc: Bornholm, Denmark
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5701378 - 02/26/13 10:45 AM
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Going from 8" to 12" is a tremendous jump! Did it myself, going from a C8 to a 12" Meade Lightbridge. The performance increase is VERY noticeable.
The Obsession is of a much higher quality overall than the Orion or Meade scopes. Though I really like my 12" Lightbridge, it must be noted that I have had to fix some issues and upgrade it here and there.
Clear skies! Thomas, Denmark
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CosmoSat
scholastic sledgehammer
Reged: 07/24/09
Loc: India
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Re: thoughts on the 12.5 Obsession
[Re: Astrojensen]
#5701448 - 02/26/13 11:28 AM
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This video might be of some help in deciding and compare with ur current scope... Am not saying anything about optics, but the structure u will definitely like. http://www.youtube.com/results?search_query=obsession+12.5
Clear Skies!
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coutleef
Post Laureate
   
Reged: 02/21/08
Loc: Saint-Donat, Québec, Canada
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Re: thoughts on the 12.5 Obsession
[Re: CosmoSat]
#5701466 - 02/26/13 11:34 AM
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i made that jump and it is very noticeable. as for the obsession the biggest difference will be in the quality of mirror and smotthness of movement
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derekdann30
member
Reged: 02/26/10
Loc: Elizabeth City, North Carolin...
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Re: thoughts on the 12.5 Obsession
[Re: coutleef]
#5701737 - 02/26/13 01:57 PM
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Thank you folks. I've also been debating for about half the price, an Orion XX14i truss dob. Visually how would it compare with the 12.5 Obsession? Some of my favorite objects to observe are the planets. Would I be able to pick out minute detail and crisp structures on Jupiter with the 14 when well collimated?
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Achernar
Postmaster
   
Reged: 02/25/06
Loc: Mobile, Alabama, USA
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5702337 - 02/26/13 07:38 PM
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Going to a 12.5-inch from an 8-inch will result in a massive difference in what you can see. Many objects that are invisible through an 8-inch will appear through a 12-inch, and most of what you can see through your 8-inch will be noticeably easier to see, and show more detail through a 12-inch. Best of all, you get big aperture performance in a telescope that will fit into any car.
Taras
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18UCinVA
professor emeritus
   
Reged: 10/24/08
Loc: Virginia
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5702375 - 02/26/13 08:07 PM
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I just sent you an email.
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Would I be able to pick out minute detail and crisp structures on Jupiter with the 14 when well collimated?
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GeneT
Ely Kid
   
Reged: 11/07/08
Loc: South Texas
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5702395 - 02/26/13 08:23 PM
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Quote:
Thank you folks. I've also been debating for about half the price, an Orion XX14i truss dob. Visually how would it compare with the 12.5 Obsession? Some of my favorite objects to observe are the planets. Would I be able to pick out minute detail and crisp structures on Jupiter with the 14 when well collimated?
Given the choice between a 12 inch Obsession and a 14 inch Orion, I would go with the Obsession. The Obsession will be easier to haul, set up, and take down. A lot of people like the Orions, and I am not putting them down. The best thing to do would be to go to a star party and try them both.
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Mike B
Starstruck
   
Reged: 04/06/05
Loc: shake, rattle, & roll, CA
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Re: thoughts on the 12.5 Obsession
[Re: GeneT]
#5703713 - 02/27/13 03:35 PM
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I would go with the Obsession.
I think i'd agree with that myself. Even tho it's certainly not a toss-up for price! The ObDob is still waay more... but for *performance*, optical *AND* mechanical, the modest diff in aperture wouldn't be enough to tip my scales toward the larger.
Yet it might be arguable that the 14i's mirror could even be refigured, and other doodads refined, to where the mechanical diff's might not be quite as significant- and this could probably be done for LESS than the cost of the ObDob new... 
But i still recall using a 12.5" Obsession for a few minutes... the views were impeccable! And the movements were like soft butter... and the weight of the components was like feathers. The Orion Dob is a beast by comparison! This aspect would weight (pun intended) heavily in *my* choice... but perhaps not everyone's.
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CarlDD
sage
Reged: 07/23/07
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Re: thoughts on the 12.5 Obsession
[Re: Mike B]
#5703781 - 02/27/13 04:16 PM
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I own an early production 12.5 Obsession and yes it's a fine scope, but, not perfect outof the box. Be prepared to work on the secondary holder ( I changed to an astrosystems 4 screw design ), the sling ( I swapped to a Howie Glater wire sling) and sorry to say - I had to get my mirror recoated as the coating started to flake off after 6 to 7 years. Movement is smooth, Argo Navis was easy to install and makes finding stuff simple. The optional Light Shroud is essential, if you choose a telerad, get the 4 inch riser. The standard JMI focuser works fine and is probably improved and even better now. The woodwork is very good on the outside, varnish is fine after nine or ten years. The scope is so good now I cant imagine being without it. Best Regards Carl
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gaz-in
professor emeritus
   
Reged: 12/17/07
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Re: thoughts on the 12.5 Obsession
[Re: CarlDD]
#5704816 - 02/28/13 07:39 AM
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IMHO....also look at Teeter Telescopes...mine was near perfect out of the box...
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GeneT
Ely Kid
   
Reged: 11/07/08
Loc: South Texas
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Re: thoughts on the 12.5 Obsession
[Re: Achernar]
#5705292 - 02/28/13 12:50 PM
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Quote:
Going to a 12.5-inch from an 8-inch will result in a massive difference in what you can see.
Totally true--a 12 incher gathers twice the light of an 8.
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derekdann30
member
Reged: 02/26/10
Loc: Elizabeth City, North Carolin...
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Re: thoughts on the 12.5 Obsession
[Re: GeneT]
#5705505 - 02/28/13 02:57 PM
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Thanks for all the wonderful replies, folks. I really am looking forward to the making the jump from an 8inch to a 12 inch.
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Markovich
professor emeritus
   
Reged: 05/22/07
Loc: Central Ohio
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5706064 - 02/28/13 07:41 PM
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Ive seen a few newer 12.5" Obsessions, beautful scope.
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Thomas Karpf
Pooh-Bah
Reged: 02/09/09
Loc: Newington, CT
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Re: thoughts on the 12.5 Obsession
[Re: Markovich]
#5706706 - 03/01/13 07:29 AM
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If you're buying that NEW, you definitely want to look at the Starstructure 12.5" with a Carl Zambuto mirror. Currently $3495. WELL worth the additional $200 above the price of the Obsession.
http://www.starstructure.com/starstructure3_007.htm
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MDavid
member
Reged: 11/15/11
Loc: 29°N (Texas)
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Re: thoughts on the 12.5 Obsession
[Re: GeneT]
#5706838 - 03/01/13 09:33 AM
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GeneT,
Speaking of new scopes...How much did you pay for the 12.5 Porta Ball? I've reached out Mag 1 but haven't heard back from them...Thanks!
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Thomas Karpf
Pooh-Bah
Reged: 02/09/09
Loc: Newington, CT
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Re: thoughts on the 12.5 Obsession
[Re: MDavid]
#5706854 - 03/01/13 09:40 AM
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The price on the 12.5" Portaball last year was $5,195. I have no idea what the current price might be.
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MDavid
member
Reged: 11/15/11
Loc: 29°N (Texas)
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Re: thoughts on the 12.5 Obsession
[Re: Thomas Karpf]
#5707059 - 03/01/13 12:04 PM
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Quote:
The price on the 12.5" Portaball last year was $5,195....
ouch, I think I may need Ocean's assistance... 
Thanks!
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Starman1
Vendor (EyepiecesEtc.com)
   
Reged: 06/24/03
Loc: Los Angeles
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Re: thoughts on the 12.5 Obsession
[Re: MDavid]
#5707332 - 03/01/13 03:00 PM
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That Starstructure is the bargain of the bunch. And nicer than the Obsession in many ways, which I won't go into here. I would, however, request it with a 2.6" secondary mirror, not a 2.14" if you plan to use low-power, widefield eyepieces like the 31 Nagler. If your interest is primarily planetary nebulae, planets, and Moon and double stars, or you only plan to use 1.25" eyepieces, the supplied secondary is OK.
12.7" is 2.512X the light grasp of an 8" (exactly one magnitude deeper reach), so the 12.5" is very close to gaining a magnitude on the 8". This doubles and more the number of DSOs visible because there is a much larger portion of universe seen. I've estimated the maximum number of objects visible to the experienced observer in pristine skies at ~15000 for an 8" and ~32000+ for a 12.5".
A 12.5" truss scope breaks down into sections that are easy to transport and move (in fact, my 8" LX200 was heavier overall) and will still yield a nice large low power field.
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dscarpa
Carpal Tunnel
Reged: 03/15/08
Loc: San Diego Ca.
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5707383 - 03/01/13 03:35 PM
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The problem with the 12.5" Starstructure is it's no longer made. I checked it out while on my newt quest. David
Edited by dscarpa (03/01/13 03:38 PM)
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johnnyha
Postmaster
   
Reged: 11/12/06
Loc: Sherman Oaks, CA
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Re: thoughts on the 12.5 Obsession
[Re: dscarpa]
#5707395 - 03/01/13 03:44 PM
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If I was buying a dob today i would definitely buy a used custom mirror scope, there are so many great bargains out there and many are scopes that simply have been hardly used by the owner. It is a true buyers' market.
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Starman1
Vendor (EyepiecesEtc.com)
   
Reged: 06/24/03
Loc: Los Angeles
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Re: thoughts on the 12.5 Obsession
[Re: dscarpa]
#5707477 - 03/01/13 04:49 PM
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The problem with the 12.5" Starstructure is it's no longer made. I checked it out while on my newt quest. David
http://www.starstructure.com/starstructure3_007.htm
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dscarpa
Carpal Tunnel
Reged: 03/15/08
Loc: San Diego Ca.
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Re: thoughts on the 12.5 Obsession
[Re: derekdann30]
#5707491 - 03/01/13 05:00 PM
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I saw that ad and called called Starstructure. I was told that they didn't make it any more. David
Edited by dscarpa (03/01/13 09:25 PM)
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jboege
super member
   
Reged: 03/15/05
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Re: thoughts on the 12.5 Obsession
[Re: dscarpa]
#5707657 - 03/01/13 07:20 PM
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I also was told the same months ago.
Quote:
I saw that ad and called and called Starstructure. I was told that they didn't make it any more. David
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Joe Bergeron
Vendor - Space Art
Reged: 11/10/03
Loc: Upstate NY
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Re: thoughts on the 12.5 Obsession
[Re: Starman1]
#5715606 - 03/05/13 11:30 PM
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Quote:
Quote:
The problem with the 12.5" Starstructure is it's no longer made. I checked it out while on my newt quest. David
http://www.starstructure.com/starstructure3_007.htm
They no longer make the scope, but they leave the page up on their site? Sloppy.
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Deb and Todd
sage
Reged: 05/23/06
Loc: Billings, MT
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Re: thoughts on the 12.5 Obsession
[Re: Joe Bergeron]
#5718826 - 03/07/13 04:59 PM
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I too started with 8" Orion and then purchased a 12.5" Obsession several years later.
I more than pleased with the Obsession. That said, i still use my 8" quite often for a number of different reasons, most of which I've posted at different times on this forum.
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George N
Carpal Tunnel
   
Reged: 05/19/06
Loc: Binghamton & Indian Lake NY
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Re: thoughts on the 12.5 Obsession
[Re: Deb and Todd]
#5728097 - 03/12/13 12:39 PM
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Teeter scopes are really nice, and the Starstructure (if still made) is also. Out-of-the-box they’re somewhat better scopes performance wise (aesthetics is too personal to comment on). However, what’s the wait time on these? You can probably get a new Obsession of any size in about two weeks, and adding a few improvements is not that big of a deal.
Of course the best deal on ‘wait time’ is to buy used. I got my 20-inch Dob the day after I saw it on AstroMart….. and the prior owner had done all of the “improvement work” that I wanted, except for a Glatter sling.
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ohioalfa64
member
Reged: 08/16/12
Loc: Ohio
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Re: thoughts on the 12.5 Obsession
[Re: George N]
#5730502 - 03/13/13 02:48 PM
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I have a 12.5 f/4 custom mirrored truss Dob. When it becomes time to upgrade to a larger Dob, I assume there is no point unless it is at least 15-16 inches. I don't want a larger one beyond that because I want to remain standing on ground. Prices for used truss dobs here on CN and on AM appear to be slightly over double for a 15-16 inch f/4 to 4.5 versus what I paid for the 12.5". All other components being equal is this a good standard rule for relative Dob value ($ Dob 12.5" x2+ = $ 15-16" Dob)?
Edited by ohioalfa64 (03/13/13 02:49 PM)
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Starman1
Vendor (EyepiecesEtc.com)
   
Reged: 06/24/03
Loc: Los Angeles
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Re: thoughts on the 12.5 Obsession
[Re: ohioalfa64]
#5730582 - 03/13/13 03:52 PM
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Quote:
I have a 12.5 f/4 custom mirrored truss Dob. When it becomes time to upgrade to a larger Dob, I assume there is no point unless it is at least 15-16 inches. I don't want a larger one beyond that because I want to remain standing on ground. Prices for used truss dobs here on CN and on AM appear to be slightly over double for a 15-16 inch f/4 to 4.5 versus what I paid for the 12.5". All other components being equal is this a good standard rule for relative Dob value ($ Dob 12.5" x2+ = $ 15-16" Dob)?
Well, unless you are very short, a 12.5" f/5 would also have allowed you to observe without a ladder or stool. Keeping the focal length about the same to avoid a ladder goes: 15"--f/4.2 16"--f/3.9 18"--f/3.5 20"--f/3.1 Since prices go up tons with shortness of f/ratio (a 20" f/5 is 2/3 the price of a 20" f/3, for example), the scope prices will rise more than simply materials cost as they get larger because the f/ratios will shrink. The f/ratio of the 15" and the 20" are both close to standards available from some makers today, but prices for a 20" f/3 are literally astronomical (though still less than a 16" SCT).
I would argue that though there is a 'little' difference in magnitude reach between a 12.5" and a 15", that difference is not worth spending a lot of money to achieve. I've looked through a LOT of scopes, and, for me, it takes at least an 18" to produce a noticeably better image of really faint targets. Even a 16" is only marginally better than a 12.5" at reaching faint targets. If you change, you want the extra weight and size to have been worth it, and moving up so little just won't slap you in the face with the difference to the point where you will think the big increase in weight was worth it. For me, 20" is the next logical step after 12.5", because you gain a magnitude and everything is really better in the eyepiece. 18" is OK. But 16" or smaller? I wouldn't bother.
Which is why I still have a 12.5".
But it does depend on the deal. I went from 8" to 12.5" for <$500 upcharge from the selling price of the 8". If you can get that kind of deal, then why not?
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Mike B
Starstruck
   
Reged: 04/06/05
Loc: shake, rattle, & roll, CA
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Re: thoughts on the 12.5 Obsession
[Re: Starman1]
#5730730 - 03/13/13 05:20 PM
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Even a 16" is only marginally better than a 12.5" at reaching faint targets. If you change, you want the extra weight and size to have been worth it, and moving up so little just won't slap you in the face with the difference to the point where you will think the big increase in weight was worth it.
I'd agree with that appraisal, with one exception; if one wished merely to *optimize* their scope for their ability to use & enjoy, why not go for the scope that is the most aperture as well as the most weight & size one can manage, for the max budget one can support?
Quote:
...because I want to remain standing on ground
Another excellent point of consideration- one with which i'm 100% into myself! So one could, logically, look at max EP height- then consider a chart of ladderless size+FR options, precisely as Don posted (above)... then pick the aperture/F# where your budget yells "uncle".
If that happens to fall at a 2" aperture bump from where you are, or 3", or 4"- who cares? You now have a max-scope that fits YOU as best as can be done. Nothin' left layin' on the table.
Then go out & enjoy it!
The Dob in my sigline is the result my own, personal version of precisely this selection process.
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Aquarist
sage
Reged: 08/27/12
Loc: Illinois
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Re: thoughts on the 12.5 Obsession
[Re: Mike B]
#5732108 - 03/14/13 11:51 AM
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Does a 12.5 inch dob require dark skies to reap the benefits of an upgrade?
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Starman1
Vendor (EyepiecesEtc.com)
   
Reged: 06/24/03
Loc: Los Angeles
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Re: thoughts on the 12.5 Obsession
[Re: Aquarist]
#5732251 - 03/14/13 01:23 PM
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Does a 12.5 inch dob require dark skies to reap the benefits of an upgrade?
An upgrade to the 12.5" or an upgrade in size? Not clear.
But if you mean upgrading in size, there is a general truism in telescopes: the larger the scope, the fainter the objects seen, regardless of light pollution.
I live in LA, and believe me, my night skies are REALLY light-polluted. I often say my night skies are orange, what color are yours? Yet, my 12.5" simply blows away my 5" Maksutov with what can be seen. In dark skies, M13 is resolved in the 5", but in the city it is merely a dull glow with no resolution (well, maybe a few outlier stars). The 12.5" resolves M13 to the core in the city and shows the small galaxy NGC4617 in the outskirts of M13 in a dark sky. Either place, the 12.5" simply shows more. The City view of M13 in the 12.5" is better than the country view of M13 in the 5".
So, aperture is aperture. No matter where you are, a larger scope goes deeper. Of course the larger scope has the same advantage in a dark sky and will show you even more.
At some point, though, you will reach a maximum size for your vehicle or your budget. But unless you have other requirements for use (such as being able to lift the entire scope and take it out on the patio), bigger scopes will show you more.
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Pinbout
Post Laureate
   
Reged: 02/22/10
Loc: Montclair
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Re: thoughts on the 12.5 Obsession
[Re: Starman1]
#5732303 - 03/14/13 01:59 PM
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I often say my night skies are orange, what color are yours?
So that's your line to pick up girls?

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George N
Carpal Tunnel
   
Reged: 05/19/06
Loc: Binghamton & Indian Lake NY
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Re: thoughts on the 12.5 Obsession
[Re: Pinbout]
#5732497 - 03/14/13 04:14 PM
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A 12.5” can be a very nice size Dob to have. I have friends, a couple in their 70’s, who own a custom made high-end 12.5 Dob built around optics from the Orion 12.5 Newt/GEM that they originally bought and found too bulky. The Dob has two handles on it, so that he can pick the entire scope up and carry it a 100 yards to a good observing field (they live under a green zone sky). She brings the eyepieces, a table, chairs, and charts. Even with checking the collimation they are ready to observe in 2 or 3 minutes. They leave the scope assembled under a cover in their garage, and also it is an easy fit into their RV. I think someone could do a lot of observing with a Dob this size.
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Jean Mario
member
Reged: 11/21/10
Loc: Québec, Canada, St-Jérôme.
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Re: thoughts on the 12.5 Obsession
[Re: dscarpa]
#5779643 - 04/05/13 01:36 PM
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It's best one !
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Mel M
super member
   
Reged: 05/04/08
Loc: southern Oregon
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Re: thoughts on the 12.5 Obsession
[Re: Thomas Karpf]
#5780487 - 04/05/13 08:47 PM
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Quote:
If you're buying that NEW, you definitely want to look at the Starstructure 12.5" with a Carl Zambuto mirror. Currently $3495. WELL worth the additional $200 above the price of the Obsession.
http://www.starstructure.com/starstructure3_007.htm
For years Obsession has claimed the full thickness 2" mirror gave their 12.5" an advantage. Their web site said they didn't use those thin, bendy, potato chip mirrors.
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