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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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I will only have one EP with less than a 1m pupil, the 4mm plossl I already have. All are less than ~4.4mm. Of course, if they are barlowed, some will not be as useful.
All but 2 of the other EP's will fall between 1 and 2 with multiples of 6 being the closest.
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Zhumell 8" Dob
Edited by JasonNB (07/30/08 12:58 PM)
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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I have come to an un-important conclusion... I'm about as decisive as a kindergarten spit-wad fight....
I like all the suggestion given..
In terms of Exit pupil being at 1mm and 2mm, 6mm and 12mm seem to be my target FL's.
a) 13 Hyperion + 28mm ring
This combo give me 13mm, 9.2mm, and 22mm without barlow, and 6.5, 4.6, and 11 with. Lots of bang for $135 in an ep that all reviews generally agree on. My perception; good for DSO's, unknown on planets, good for lunar.
b) 6, 9, and 15 Expanse clones
6, 9, and 15mm without barlow, 4.5 and 7.5 with (3 would be unusable I think) Cost:$100, Reviews mixed, esp. at F6, but 6 and 9 are usually favorable, 15 often favorable. My perception: OK for planets, OK for DSO's, questionable for lunar.
c) Bill P's suggestion to build a collection of 6 and 9 expanse clones with 13 and 24 Hyperions.
Maybe start with the 13 hyperion and a 6 or 9 Expanse clone if I can swing the $$$ ???
I guess part of my dilemma is how to hyperions and expanses do on planets?
Wish there was a shop where I could go check these out, but that doesn't seem to exist around here and my ability to travel to the area astro group is nill for the forseable future.
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Zhumell 8" Dob
Edited by JasonNB (08/01/08 11:34 AM)
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Lamb0
professor emeritus
Reged: 07/25/07
Posts: 668
Loc: Fairbury, Nebraska
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 Do NOT waste your hard earned money on inexpensive 80° AFoV eyepieces in your Zhumell 8" Dob. The ~70° SuperWides are OK, the Hyperions are better, but, IMHO, the cheap 80° AFoV eyepieces can bite a fast scope they need an f/8 or slower for decent perfomance! 
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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Thanks Lamb0. I'm really leaning toward picking up the 6 and 9 expanse cones while I watch for a used 13mm hyperion to float by.
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Zhumell 8" Dob
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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Well, as luck would have it, I stumbled on a very gently used 13mm Hyperion with tuning rings that is now on its way to me for quite a bit under retail, so, my plan is now for some new or used Expanse/clones to try out.
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Zhumell 8" Dob
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Alleline
professor emeritus
Reged: 02/07/06
Posts: 583
Loc: Farmington, New Mexico
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I have a 9mm Expanse clone and it performs quite nicely in my F9 refractor - generous eye relief, and very lightweight. I got it used for $40. Or get a GSO 20mm Superview ($45 new at agenaastro.com) and a barlow. The 20mm Superview barlows very nicely.
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Tom
Meade DS-16 (F4.5), C-8, Synta 120mm F8.3 refractor.
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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I have a new 2" ED barlow on the way as well.
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Zhumell 8" Dob
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Lamb0
professor emeritus
Reged: 07/25/07
Posts: 668
Loc: Fairbury, Nebraska
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 Good find on the 13 Hyp w/rings! I expected to be dissapointed by the Expanse, but the 8" f/6 at Hyde Observatory shows nice views, (I forget which FL) - it's good to be proven wrong, sometimes! 
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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From what everyone says, the 6 and 9 Expanse/clones should be a nice way to fill out my higher power ep's with better glass than my basic Zhumell plossls.
Alleline, how does the expanse clone do on planets?
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Zhumell 8" Dob
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Alleline
professor emeritus
Reged: 02/07/06
Posts: 583
Loc: Farmington, New Mexico
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I have not used the 9mm Expanse clone for planets. For a while I used a 15mm TV plossl with 2x and 3x TV barlows - liked that quite a bit. I recently switched to a Pentax XF 6.5-19mm zoom and sold the plossl. But my skies are not the greatest and there's seldom any minute detail to be seen in anything. I probably horrified a million users by saying I use the Pentax zoom as a planetary EP.
Anyway, the issue here is tracking. With an EQ mount or a tracking platform for your dob, you would only want a widefield EP for planetary observation in exceptional circumstances like a conjunction. The rest of the time there is very little to be gained. With an unpowered dob, of course, the advantage to a wide field is keeping the object in the FOV. At <$50, the Expanse is probably a good bet.
My opinion is always that you do better with better glass. A 7mm XW used is only $200 more than a new 9mm Expanse. Wait a few weeks and get the XW, would be my native inclination. It's superior in every way to the Expanse, cheaper than a tracking platform, and you will use it in any scope you buy. If not, you can sell it for what you paid and all you lose is the shipping costs.
With three good eyepieces and a barlow, you can see and enjoy more than with a dozen mediocre eyepieces. I have nothing against Expanses and Superviews. Part of me wishes I had stuck with the 8" Orion on a Skyview Deluxe mount and three Superviews - and saved $5k on other equipment over the years. But once you head down the slippery slope of wanting an eyepiece for every occasion, you might as ell jump right to the end and buy a Nagler as pay your way piecemeal into the crevasse.
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Tom
Meade DS-16 (F4.5), C-8, Synta 120mm F8.3 refractor.
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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I got the Hyperion in yesterday and had a chance to briefly try it out about 8:30pm last night.
It was fairly early in the evening and not 100% completely dark. Targets were Jupiter and the moon. Seeing conditions weren't great- hot and muggy. Scope may not have been 100% acclimated yet either.
The moon completely filled the FOV and was insanely sharp compared to my other ep's.
Jupiter: in my old ep's Jupiter is a bit washed out. the colors seem muted. In the Hyperion, they popped. Contrast was much better, and the planet was brighter. I added my Zhumell 1.25" barlow, and was sadly dissappointed. Colors were shot and the contrast was worse. May have been conditions, but I suspect a better barlow would help.
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Zhumell 8" Dob
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Mike B
Starstruck
Reged: 04/06/05
Posts: 4460
Loc: shake, rattle, & roll, CA
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Jason-
That the 13mm Hyp would view well in yer Dob is little surprise- its operating at ~2.2mm exit-pupil (13mm/F5.9=) which should be perfect for general viewing! Truthfully, most of my viewing falls b/t 1.5-2.5mm ex-p.
However, the Barlow's effect is not a surprise, either. Many of these "2x" Barlows actually function at ~2.2-2.3x, so that would've jumped you all the way to 1.0mm ex-p, and very likely PAST the window of optimal seeing... the downhill slide after that window can be dramatic! Like what you saw.
A very highly rated Barlow is the Antares 1.6x unit, which actually functions nearer to its name. Not only is it a 2" job, good for boosting your big 2" EPs into medium FL ranges, but it'll have that 13mm Hyp singing at ~FL8mm... ~1.4mm ex-p.
Planetary viewing can make a fellow a little goofy on EPs  ... like me f'rinstance: I've got 17mm, 15mm, 12.5mm, & 10.5mm EPs well suited for planets, helping me fine-tune to current atmo conditions. Now on order is an 11mm set to add ridiculous to the sublime. 
But i'm having fun! And all but one of the above are relatively inexpensive EPs (Ploessls, Orthos, RKEs).
Enjoy the trip!
mike b
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Just for giggles- Next time when the money comes out the ATM, scream "I Won!, I Won!"
* * 15" F4.55 Starsplitter Dob * *
 Pacheco State Park
 Fremont Peak
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JasonNB
member
Reged: 11/21/06
Posts: 98
Loc: Spring Hill, TN
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Mike, what EP's are you using for planets?
I already have a 2" GSO ED barlow on order. Unfortunately, it won't be in sock until early October..... 
I have the 6 & 9 expanse clones in my cart at Agena, just haven't pulled the trigger. I really want something that does well on planets and I'm not so sure the 6 is it.
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Zhumell 8" Dob
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