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Rugged, affordable tools for dirty jobs.

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#1 jrbarnett

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Posted 26 November 2012 - 08:46 PM

I like nice stuff. No doubt about it, the level of correction achieved by modern eyepieces in fast scopes is obvious and beneficial. But nice stuff typically costs a pretty penny. For use at home, under controlled conditions, that's fine. One could observe for a lifetime and not materially impair or degrade nice eyepieces, for example.

But let's say that you also observe in very, very harsh environments at times. Very cold, very hot, very windy, very moist, very dusty, etc. The kind of conditions that, given time and exposure, would take their toll on your nice stuff.

So...

I'm going to snag an f/5 mass-market Dob for use during my semi-annual dark sky camp-outs, and want some "guiltless use 'em and abuse 'em" eyepieces to go along with the dob. Here are my requirements.

I want reasonable correction for astigmatism at f/5. I also won't be using Paracorr, so there will be some coma no matter what, so I don't need Nagler/Ethos levels of correction. I want three or four eyepieces, including a 2" finder eyepiece, a one or two medium power, medium or wide field eyepieces and a single higher magnification eyepiece. Figure the focal length of the scope will be between 1200mm and 1500mm. I'm not looking for massive high magnification at the short focal length end, either. Maybe ~250x tops (I want a high power eyepiece that I can use every night rather than only occasionally).

The other key restriction is this: I do not want eyepieces that cost more than $100 each. That includes the 2" finder. So with that in mind, please make your recommendations.

Thanks,

Jim

#2 Bob S.

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Posted 26 November 2012 - 08:51 PM

Jim, I would try and snag a mass-market Dob with an upgraded primary. I have purchased a number of them used and they are unbelievably superb instruments and not all that expensive given how they perform. Bob

#3 Wallcreeper

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Posted 26 November 2012 - 09:20 PM

Maybe the 40mm Sterling Plossl for the 2 inch finder ($80).

#4 jack45

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Posted 26 November 2012 - 09:25 PM

23mm Axiom LX used for one.

C;ear skies!

#5 Pinbout

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Posted 26 November 2012 - 09:32 PM

that's why I grab this 8inf6 homebuilt for $100 including 1/4~ primary. I had to upgrade the secondary cause it was .7~ not flat although smooth. its nice to be able to test the optics myself.

I had to tear it apart to make the bearings bigger and also open the bottom to make a tailgate, new truss connectors and make new uta. I'll probably bondo the sides and paint everything black.

I hate mass produced small bearings.

it packs up sooooooo nicely in my civic.

and best of all I would mind kicking it down the stairs [without the optics]

I just fitted it with uhmw instead of teflon and its static/dynamic frictions are relatively equal, but it is stiffer than teflon but still smooth.

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#6 Adam Taylor

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Posted 26 November 2012 - 09:33 PM

How about an Agena SWA 32mm @ $75. for the finder EP (Is 6.5mm exit pupil too big you?).

And, Celestron X-Cel LX / Meade HD-60 @ $70-80. for the rest.

All very comfortable to view through too.

#7 frito

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Posted 26 November 2012 - 10:41 PM

some plossls??

#8 jrbarnett

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Posted 26 November 2012 - 10:53 PM

How do the 2" Sterlings do at f/5?

Also, because it's an obstructed scope, I suspect the 30mm would offer less risk of seeing the shadow of the secondary. I do like the full set price for the Sterlings though.

Regards,

Jim

#9 dlapoint

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Posted 26 November 2012 - 11:05 PM

Can't beat the sterlings, work good at f5 anf dirt cheap. You might want to look at a few es ep's the 24mm 68, 16mm 68 8.8mm 82, and 6.7mm 82

#10 Jon Isaacs

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Posted 27 November 2012 - 05:05 AM

I'm going to snag an f/5 mass-market Dob for use during my semi-annual dark sky camp-outs, and want some "guiltless use 'em and abuse 'em" eyepieces to go along with the dob. Here are my requirements.



I will just say this:

These trips represent the best conditions you are likely to experience during any given year. Take your best and enjoy it because this is when quality equipment can really shine. Coma and astigmatism are partially hidden by less the pristine skies, when the skies are dark and clear, the difference between "affordable" eyepieces and the good ones are most noticeable.

I might spend an evening in my backyard with my TV Widefields and TMB Planetary's but the Naglers always go to the dark sites.... I bought 'em to look through, not look at.

YMMV

Jon

#11 Keith

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Posted 27 November 2012 - 07:07 AM

I am going to second the used 23 axiom LX as a finder, it has about 85 degree field and works extremely well at f5, I used one for a while with a 10"DSO. They have moved on to a new home. $100 used, $150 new while supplies last. Can't beat it at that price, plus the extendable eyeguard makes it easier to protect the lens while viewing. It is heavy, but with the stock springs on the dob, both attached, it works fine. YMMV if you get an "adjusable tension" dob or one without tension adjustments, like the lightbridge (the litle brake thing they added wasn't very good IMO)

#12 BDS316

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Posted 27 November 2012 - 07:41 AM

30 and 17mm Sterlings

9 and 6mm Expanse clones from Owl or Agena

With a 1250mm 10 inch f/5 econodob this would give 42x with a 1.4 degree field, 74x with a 0.8 degree field, 139x with a 0.5 degree field, and 208x with a 0.34 degree field.

Okay?

#13 bdcmd

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Posted 28 November 2012 - 01:01 AM

From reading your original post, the message I get is that you want decent quality, but essentially "disposable" eyepieces, i.e. something you wouldn't mind chunking at a lurking coyote. Considering that, I would think anything along the lines of any of the ES eyepieces would be way too nice. My choices, given the above, would be: for the widefield 2", the 30mm SuperView. Alternative would be the 30mm 2" Sterling plossl, which actually works pretty well in my f/4.8 ES Comet Hunter. For the mid-powers, I would think you are using these for DSOs, so wide-ish fields would be better. The best bargains here would seem to be the various 60 degree e/p's such as Paradigms, X-Cel LX, HD-60. Paradigms are cheaper, so probably the 15mm as it gives a 3mm exit pupil, 80-100x depending on scope focal length. Or 18, you pick. High power says planetary viewing to me, so two ways to go: if you want minimal glass, the KK orthos at 6 or 7 mm (hurry before they disappear). Actually, the TV 8mm plossl would also qualify, but, like the ES eyepieces, probably a little too dear to chunk at a coyote. :grin: If wider fields to make using an undriven dob easier, the Celestron X-Cel LX 7mm. Except for the KK orthos (and TV plossl), all the above are very inexpensive, easily replaced, and at least decent.
So, what does the Eyepiece Hooligan himself think would be the best choices?

#14 Keith

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Posted 28 November 2012 - 01:28 AM

If you want to go on effectiveness against large animal attacks, I would stay away from the featherweight 30mm superview, and go for one of the chinese widescan II clones, like the 1rpd, Agena UWA, OWL, BW-OPTIK etc... That sucker is 80deg (high 70's realistically), and even flattened out surprisingly well with the paracorr (something I can't say about any of the other cheap widefields). The thing is very heavy, very dense, and almost has a russian military feel to the finish. Mine is the 1rpd, had it for many years, $55 used, and I have seen others for the same price, and less than $100 new.

I always considered it as a weapon, and it tended to live in my duffel in a bolt case, rather than in one of the EP cases. I am like John, I bring my good stuff out for the few times I get to dark skies, and here is about as dusty as it can get at some of the desert sites, even up at RTMC there is this fine dust that gets on everything. So yeah, I have to clean the 31 nagler from time to time. The 1rpd is at the ready as a projectile. To have similar effect, an 8mm plossl would require more velocity and impeccable aim.

#15 Keith

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Posted 28 November 2012 - 01:30 AM

I think I need to find the perfect sized rock, and keep it in a bolt case too

#16 dpwoos

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Posted 28 November 2012 - 02:51 AM

I bought 'em to look through, not look at.

Jon


Me too!

#17 Jon Isaacs

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Posted 28 November 2012 - 07:56 AM

30 and 17mm Sterlings

9 and 6mm Expanse clones from Owl or Agena

With a 1250mm 10 inch f/5 econodob this would give 42x with a 1.4 degree field, 74x with a 0.8 degree field, 139x with a 0.5 degree field, and 208x with a 0.34 degree field.

Okay?


The 6mm and the 9mm Expanses are good choices for a 10 inch F/5, surprisingly wide FOV and quite well corrected. I don't know about the Sterling Plossls.

I am a bit surprised that will all his eyepieces, Jim does not already have a second string set just for such occasions. I have a second string set that has seen a lot of use, a lot of miles and yet it does a decent job in a fast Newtonian. It's the set I take to the beach when we have a bonfire, I took it with us when we recently did a 7000 mile trip car-camping around the west, I didn't have the space for my main set.

It looks like this:

32mm, 24mm and 15mm TV Widefields, 9mm, 6mm and 4mm TMB Planetary's a 2X Celestron Shorty Barlow and a Lumicon Deepsky filter.

The TV Widefields are a bit spendy but for several years they were my best eyepieces, lots of warm memories and I still use the entire set quite frequently.

Jon

#18 Sarkikos

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Posted 28 November 2012 - 08:38 AM

I have a Sky Watcher clone of the 9mm Expanse. In fact, I have two for binoviewing. I like them. Wide field, bright image, good correction. I also have an Owl clone of the 6mm Expanse. IME, not so good in my 10" f/4.8, despite the good reviews. I sold mine a couple months ago. IMO, an LER 6mm is much better, brighter field, better corrected. IIRC, BillP liked the Owl/Expanse 6mm. I think that's the only time I've had to disagree with his assessment of an eyepiece. :shrug:

Mike

#19 Sarkikos

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Posted 28 November 2012 - 08:53 AM

My contrarian advice about "finder eyepieces:"

Get a good finder scope instead. I have a 70mm short tube achromat which I mount on my 10" f/4.8. I insert an Amici prism for an erect and correct image, and use an Orion illuminated reticle eyepiece. I also put a reticle/crosshair eyepiece in the main scope's focuser. Then I align the finder scope to the main scope using the two reticle/crosshair eyepieces. This way I reach a very close alignment.

After that, I don't need a finder eyepiece. I just use the finder! All I need to do is place the location of an object at the crosshairs of the finder scope. Even at mid-to-high power, that object will be in the field of the main scope. :ubetcha:

I use my wide-field low-power eyepieces to view big stuff and star vistas. I never use them to find an object. That's the job of my finder scope.

Mike

#20 Sarkikos

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Posted 28 November 2012 - 09:02 AM

Good, all-around useful and inexpensive eyepieces: AT Paradigms.

Mike

#21 Doug Culbertson

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Posted 28 November 2012 - 09:19 AM

Good, all-around useful and inexpensive eyepieces: AT Paradigms.

Mike


+1 I foolishly sold my Paradigm pairs a year or so ago when I thought that I was done with binoviewing. I plan to grab a couple more pairs, as well as a couple of singles for my travel kit.

I also agree with the above comments on the 9mm Expanse clones.

#22 csrlice12

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Posted 28 November 2012 - 09:47 AM

"But let's say that you also observe in very, very harsh environments at times. Very cold, very hot, very windy, very moist, very dusty, etc. The kind of conditions that, given time and exposure, would take their toll on your nice stuff."

So, you'll expose yourself to those conditions (it takes a toll on YOU too), but be gentle to the equipment? Nah, if I'm gonna abuse myself, my equipments gonna suffer right along with me.....

#23 Jim Romanski

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Posted 28 November 2012 - 10:17 AM

For a finder eyepiece I lived for years with the Orion 32mm Erfle that used to sell for $99 (I think). I don't know if they still have it or if you'd consider used but it's a good eyepiece and I used it pre-Paracorr with no regrets. I think I also took out the field stop and it's very wide but not so well corrected after the field stop.

Personally, I prefer wide field eyepieces especially with a dob. For the shorter focal lengths you could buy some ES 82 degree eyepieces and not really compromise.

#24 jrbarnett

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Posted 28 November 2012 - 11:48 AM

My Naglers, XWs and Ethoses are in my "second stringers". :grin:

We're looking for Double-A ball players here. Puma-fodder. Mojave Green bait. Doubles nicely as a golf tee for driver practice.

- Jim

#25 kkokkolis

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Posted 28 November 2012 - 12:01 PM

You might abuse them a lot, no remorse:
Agena 2" Ultra Wide Angle (UWA) Eyepiece - 20mm (30mm without the barlow)
Agena 1.25" Enhanced Wide Angle Eyepiece - 9mm
Agena 1.25" Enhanced Wide Angle Eyepiece - 6mm

I had those Orion Expanse clones and gave them away considering I wouldn't use them because I ordered the 10 and 6mm Delos. Silly of me. They were very decent, easy viewers and lightweight eyepieces to abuse.
I also enjoyed the Agena 1.25" Super Wide Angle (SWA) Eyepiece - 20mm. You might get this one with a Agena 2" Super Wide Angle (SWA) Eyepiece - 32mm $195 for all 4 eyepieces and maybe half this amount for used ones.






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