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Equipment Discussions >> Eyepieces

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sage
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DO BAADER HYERIONS COME CLOSE TO PENTAX XW
      #5677203 - 02/13/13 08:30 AM

im hearing there great eyepieces,im mostly into the planets.thx

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dscarpa
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677389 - 02/13/13 10:42 AM

No. David

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sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: dscarpa]
      #5677431 - 02/13/13 10:55 AM

really,ok thx much

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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677574 - 02/13/13 12:08 PM

Next time, let's control the urge for lengthy responses...

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sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: csrlice12]
      #5677585 - 02/13/13 12:16 PM

i would have like a little more elaboration.but i guess reviews could be somewhat bias.

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coutleef
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677620 - 02/13/13 12:40 PM

it all depends what you call close and in which scope.

but unfortunately they are in a different league in terms of price and performance.


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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: coutleef]
      #5677629 - 02/13/13 12:48 PM

I do agree with David though.

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Jon Isaacs
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677660 - 02/13/13 01:06 PM

Quote:

i would have like a little more elaboration.but i guess reviews could be somewhat bias.




In general terms, swapping telescopes make the big, hit you in face, can't miss differences, swapping eyepieces make subtle differences.

People argue about whether the Nagler T-6 or Delos is better than the Pentaxes, (depends on your scope) but they Hyerions are not quite at that level.

Jon


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howard929
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677674 - 02/13/13 01:17 PM

To my tiny brain, the ES 82's for $99 make all of those $60-$70 eyepieces into also rans and the Hyperions for $139 seem like ... Well, I can't say it.

Eye relief and the annoying large FOV that some report non withstanding. YMMV.


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tomharri
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: howard929]
      #5677686 - 02/13/13 01:23 PM

The Hyperions are terrible in short focus scopes. Tried the 13 and 17 in my f/5.6 and the outer third of the field is out of focus. The Pentax XW's work in any scope and are the best planetary lenses just like the Delos and Zeiss.

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Starman81
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: csrlice12]
      #5677695 - 02/13/13 01:28 PM

In terms of comfortable viewing experience, yes, they come close. Hyperions have the 20mm of eye relief which many of us find very comfy. Also, like the XW's, the exit pupil is not 'fussy', meaning the Hyperions are not prone to blackout or kidney bean if you look around the apparent field of view.

Viewing aesthetics, most of the Hyperions I think do not have a sharp field stop. I have the 17 and 10mm and used to have the 8mm and only the 17mm has a sharp field stop, while the others had blurry ones, which detracts from the view and makes the FOV seem a little smaller to me than the 68* that it really is.

Light-throughput wise, XW's are among the highest rated. The XW's are known for crisp, sharp views and while the Hyperions can deliver decently, some observers with more experience than myself have characterized the views as a little 'soft'. Soft or not, while doing some casual A/B/C testing with three different 10mm eyepieces not long ago (XW/Hyperion/Delos), I could see the same detail in Messier objects in the Hyperion that I saw in the XW and Delos. I was careful to choose faint detail and stars in the objects in order to have a basis for my comparison but perhaps some more thorough testing or critical observers would be able to ferret out the differences.

As far as edge correction is concerned, the Hyperions are not so close to the XW's from what I have read. My primary scopes are not 'slow', so I cannot speak from experience on this.

In terms of size and weight, they are close as well. Price-wise, big difference, of course.


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stellar62
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: tomharri]
      #5677703 - 02/13/13 01:33 PM

I do agree with coutleef though.
Plus, the ES 82 degree is better than Hyperions.


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BillP
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677719 - 02/13/13 01:41 PM

Quote:

im hearing there great eyepieces,im mostly into the planets.thx




IMO they are not close. Hyperions are good eyepieces and I had most of them for quite a long time in the stall and enjoyed them very much. Very comfortable to use and nice sized eye lens and wide AFOV, plus the fine tuning rings were a blast to use. But the XWs have a much better off-axis in faster scopes, on-axis they are crisper with a higher apparent contrast to the image, they are also very neutral toned so colors are more vibrant. Overall a much more refined view than the Hyperion...and of course you pay for it. And in the 10mm and shorter focal lengths the XWs are essentially as good as it gets over their entire FOV. FWIW, the XWs are the only wide fields I have used that I find much more than simply acceptable for planetary observing (I'm very picky about planetary)...they are really quite capable in that specialized observing role!


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Eigen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: BillP]
      #5677730 - 02/13/13 01:48 PM

In my opinion, with the prices of the ES82 line, the Hyperion is basically redundant. The Hyperion is a very decent eyepiece but the XW is a different league.

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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Eigen]
      #5677738 - 02/13/13 01:56 PM

Compared to cameras, Hyperions are Kodak, Pentax are, well, Pentax.......

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astro_baby
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: csrlice12]
      #5677750 - 02/13/13 02:02 PM

I have owned the 5mm Hyperion and a 5mm Pentax XW. The difference is NOT subtle its HUGE.

The Pentax is more comfortable to use, doesnt incline to bean or blackout, is sharp to the edge, has fantastic contrast.

In fairness the XW is three times the price so you'd expect it to be a lot better and it is.


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howard929
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: astro_baby]
      #5677757 - 02/13/13 02:08 PM

I'm asking cause I don't know. Is the Pentax that much better then a ES 82?

Edited by howard929 (02/13/13 02:09 PM)


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Eigen]
      #5677770 - 02/13/13 02:18 PM

Quote:

In my opinion, with the prices of the ES82 line, the Hyperion is basically redundant.




I agree. The ES82s are amazingly good, unbelievably so for the price. They have made a LOT of eyepiece lines redundant, IMO.


Clear skies!
Thomas, Denmark


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sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5677790 - 02/13/13 02:33 PM

thank you very much,its been years an im back into astronomy.ive been using old celestron ultimas for my work in daylite with mercury and venus.i will get a few of those pentax.one at at time an thanks to you all.my scope is a c-8.

Edited by ROBERT FREE (02/13/13 02:34 PM)


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677794 - 02/13/13 02:36 PM

The Celestron Ultimas is nothing to sneeze at. Very fine eyepieces. Originally a Baader design, made by Masuyama. Better than the Hyperions, if you ask me...


Clear skies!
Thomas, Denmark


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coutleef
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: csrlice12]
      #5677797 - 02/13/13 02:38 PM

Quote:

Compared to cameras, Hyperions are Kodak, Pentax are, well, Pentax.......




that sums it up nicely.

in a f/10 sct. i found that the hyperion ( or stratus) was very close to naglers or even an ethos. many use the hyperions with success in sct. once your scope becomes faster or once you want to get the best view wth very small detail, suddenly the price increases significantly.. that is life,

for a designated planetary EP i would prefer a UO ortho to the hyperion. but that is very personnal

i agree with others that the ES eps are a good value for the price


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sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5677804 - 02/13/13 02:43 PM

well i do get nice images on the planets but will the pentaxes show even better.sublte details on venus i can see real good.but mercury is rare.i have seen some peculiar things in the past so im thinking a few high power pentaxes xw might just be better?

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sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5677809 - 02/13/13 02:47 PM

yes,they are fine but i think bill p convinced me.i get 1 or two high power ones an let you all know,but im sure most know this already.ive seen in the past many pecularities on venus but mercury is rare a few shadings from time to time an again a pentax ill try.

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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5677825 - 02/13/13 03:00 PM

I personally doubt that the Pentax XW's will show more planetary detail than the excellent Celestron Ultimas. Mercury is a real nasty lil' bugger and a C8 will struggle with it visually. I'd say your chances of seeing more on Mercury (or any planet) by getting different eyepieces is marginal at best. If you want drastic improvement, invest the same amount of money in a 12" newtonian and you'll be blown away by the huge difference. I know I was. My 12" Meade Lightbridge, with its astigmatic secondary and slightly overcorrected primary totally smokes my excellent C8 on planetary details. Well, it smokes it on anything, actually.


Clear skies!
Thomas, Denmark


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5677829 - 02/13/13 03:02 PM

Except double stars in summer. Here I've yet to see anything better than my C8. But the new secondary for the 12" might change that.


Clear skies!
Thomas, Denmark


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Jon Isaacs
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Eigen]
      #5677862 - 02/13/13 03:25 PM

Quote:

In my opinion, with the prices of the ES82 line, the Hyperion is basically redundant. The Hyperion is a very decent eyepiece but the XW is a different league.




I think the advantage of the Hyperion is the long eye relief... If you wear glasses while observing, eye relief is near the top of the list. I don't wear glasses while observing.

Jon


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Eigen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5677875 - 02/13/13 03:35 PM

Quote:

Quote:

In my opinion, with the prices of the ES82 line, the Hyperion is basically redundant. The Hyperion is a very decent eyepiece but the XW is a different league.




I think the advantage of the Hyperion is the long eye relief... If you wear glasses while observing, eye relief is near the top of the list. I don't wear glasses while observing.

Jon




Agreed.

Like you I am still lucky and have no need for glasses yet, makes me quick to forget the importance of ER to observers that require glasses for observing.


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LivingNDixie
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5677883 - 02/13/13 03:38 PM

The Hyperions are clones of the old Vixen LVW line. The ES 82 eyepieces are more in line with the Meade 5000 series. The Pentax XW is a totally different animal and a outstanding eyepiece series.

I would love to compare the ES82 degree eyepieces to the older Type 1 and Type 2 Naglers.


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Starman1
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5677888 - 02/13/13 03:41 PM

Quote:

I personally doubt that the Pentax XW's will show more planetary detail than the excellent Celestron Ultimas. Mercury is a real nasty lil' bugger and a C8 will struggle with it visually. I'd say your chances of seeing more on Mercury (or any planet) by getting different eyepieces is marginal at best. If you want drastic improvement, invest the same amount of money in a 12" newtonian and you'll be blown away by the huge difference. I know I was. My 12" Meade Lightbridge, with its astigmatic secondary and slightly overcorrected primary totally smokes my excellent C8 on planetary details. Well, it smokes it on anything, actually.
Clear skies!
Thomas, Denmark




Alas, the Celestron Ultimas are long-discontinued and only available on the used market. In the absence of a Celestron, the other labels under which the same eyepieces were sold will also do:
Omcon Ultima
Tuthill Super Plossl
Meade Series 4000 Super plossl (pre-1994, Japanese)
Antares Elite
Baader Eudiascopic
Orion Ultrascopic
Takahashi LE
Parks Gold Series

There are a lot of nice eyepieces out there with 45-60 degree fields that are still in production. It's when you get to 65-72 degrees that the eyepieces start separating into tiers.

I'm nearly done revising my Buyer's Guide to Eyepieces, and it's amazing, but it seems like almost 50% of available eyepieces in 2009 have disappeared by 2013. I think Jing Hua (Explore Scientific) is largely to blame because they have offered great eyepieces for less.
I've also seen an increase in offerings from Long Perng and GSO from Taiwan under other labels.

Where Mercury is concerned, the eyepiece is really of very little importance. The things that matter most are:
--extremely good seeing conditions. Without this, Mercury is a blob in all scopes.
--high clarity in the low-angle atmosphere. Low contrast features will never be visible if the atmosphere has a high extinction factor.
--complete lack of chromatic aberration in the instrument. The atmosphere will add chromatic smearing. You don't want the scope to add any.
--an elongation that allows Mercury to get farther from the horizon. There is a famous story that Copernicus never saw Mercury in his home in Padua, Italy because of coal smoke and obscured horizons. So elongation is critical. Below 10 degrees, no planet is decently viewed.


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Scanning4Comets
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5677921 - 02/13/13 04:04 PM

Quote:

I personally doubt that the Pentax XW's will show more planetary detail than the excellent Celestron Ultimas.

Clear skies!
Thomas, Denmark




I respectfully disagree. When I picked up my first Pentax XW, I immediately noticed more detail in the bands of Jupiter. The glass in the XW's is polished extremely well and has excellent coatings. Internal baffling in them is incredible also. You can see it when you look in the XW from the top.

The attention to detail in these are top notch. In checking the bottoms of these eyepiece, the same attention to detail is there as well.

Cheers,


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5677926 - 02/13/13 04:06 PM

Quote:

There is a famous story that Copernicus never saw Mercury in his home in Padua, Italy because of coal smoke and obscured horizons.




Copernicus spent several years in Padua, Bologne and Rome, but he lived most of his life in Thorn and later Warmia in Poland. He began his astronomical studies while still a young man in Poland.

Northern Poland is about 54° northern latitude. I am at 55° N and have rarely seen Mercury with the naked eye. You definitely need to know where to look and have weather on your side. But then it's not difficult to see and that Copernicus should never have seen it, due to poor conditions is probably a myth, unless he really didn't spend much effort to see it. He could have seen it easily, if he wanted.

Coal was not yet used commonly for heating in medieval times, and was mostly unknown in Europe, except England, but peat was widely used. And wood, of course.


Clear skies!
Thomas, Denmark


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5677936 - 02/13/13 04:12 PM

Quote:

I respectfully disagree. When I picked up my first Pentax XW, I immediately noticed more detail in the bands of Jupiter. The glass in the XW's is polished extremely well and has excellent coatings. Internal baffling in them is incredible also. You can see it when you look in the XW from the top.

The attention to detail in these are top notch. In checking the bottoms of these eyepiece, the same attention to detail is there as well.




That's great to know! I have tried the Baader Eudiascopics myself (same as Celestron Ultimas) on the planets, but only taken a brief look through the Pentax XWs and only on deep-sky. I was impressed with the Baaders, so that the XWs better them is impressive! My brief impression with the XWs was good, but there was nothing about the view that seemed extraordinary. Sometimes, we just get the wrong impressions, it seems.


Clear skies!
Thomas, Denmark


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BillP
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5678001 - 02/13/13 04:53 PM

Quote:

ive seen in the past many pecularities on venus but mercury is rare a few shadings from time to time




FWIW, I find Venus not all that difficult to observe cloud formations on. As long as it is positioned well then can be easily achieved. Mercury on the other hand I have not had much luck on. Positioning above the horizon, like Don mentions, probably the biggest factor. However, if I wanted to give it a serious try, I think I might look to some varied filtration rather than an eyepiece as a first choice. Certainly a less expensive route to begin with. Orange (W21, W23A) and yellow (W15) might be best bets to try to tease out some of the features.


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Starman1
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: BillP]
      #5678089 - 02/13/13 05:56 PM

Color filters definitely improve the view of Mercury, both by filtering out the brightness of the sky in which the planet is usually viewed, and by reducing the chromatic issues with the lower atmospheric viewing of the planet.
My records show:
Effective at sharpening: #25 red, #23A red-orange
Effective at seeing albedo markings: #15 deep yellow, #12 Yellow
The "in-between" filter: #21 orange.


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Scanning4Comets
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5678730 - 02/14/13 02:45 AM

This is kind of related to the original post in a way. Last night I tried out a 3.5mm Stratus I just picked up and I did a head to head against my 7mm XW + 2x GSO ED barlow.

Verdict: The 7mm XW + 2x GSO ED barlow spanked the 3.5mm Stratus even way off axis! The image of Jupiter in the 7mm XW & barlow near the field stop was sharper than the 3.5mm Orion Stratus ON AXIS!

Save your pennies kiddies, grab yourself a few Pentax XW's while supplies on the used market lasts.



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iluxo
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No they do not... new [Re: Astrojensen]
      #5678839 - 02/14/13 06:39 AM

After several bake-offs at observing nights over 40 years, the conclusions I came to are from best to worst. Price is not considered.

1. Pentax XW;
2. Nikon NAV, various Naglers;
3. TV Panoptic, Vixen LVW, TV Delos. The LVW seem to be neutral in colour whereas the Delos seem warmer, but otherwise these three types are very optically similar in all respects for similar focal lengths. The Vixen LVW range is almost unique in spanning the entire useful focal range from 5 to 42mm, parfocal, and their weights are close enough to avoid the need to rebalance most scopes.
4. The Vixen LV's and NLV's I put at #4 primarily for their smaller field of view compared to those at #3, though are otherwise similar.
5. Baader Hyperion, distinctly inferior to LVW, Panoptic or Delos. Some Hyperions have a thread around the eye lens to fit a camera adapter ring for digiscoping, potentially very useful to some.
6. Orion Stratus, worse again;
7. Various Konig, Plossl, Erfle types, mostly these designs date from the1980's and 90's though these original designs are much older;
8. RKE, a budget 3 element eyepiece, good value and very good considering it uses just 3 elements;
9. Various Kellner, Meade MA (really narrow FoV)
10. Huygens, Ramsden

As for orthoscopics, their rank depends a lot on quality. Some older 1980's examples deserve to be thrown in at #6, but the Zeiss orthoscopics belong up at #3. The Japanese KK orthos likewise belong at #3 or #4..

At the risk of insulting some, I'd have to say the 2 Masuyama's I've seen were inferior to the Vixen LV's.

I haven't tried ES eyepieces sufficiently to figure out how they compare.

Edited by iluxo (02/14/13 06:59 AM)


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Jon Isaacs
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5678857 - 02/14/13 06:53 AM

Quote:

Except double stars in summer. Here I've yet to see anything better than my C8. But the new secondary for the 12" might change that.


Clear skies!
Thomas, Denmark




What sort of fan do you have for your Lightbridge? Also, truss scopes have issues with body heat passing through the shroud... And then warm hands on the OTA cause tube currents...

Pinched secondaries on GSOs scopes are relatively common but I think the Lightbridge uses a glued secondary??

On the original topic: In the big picture, there is little difference between any two eyepieces in terms of on-axis performance. Plossl, Hyperion, Zeiss Aspheric ortho, they are all about the same, in the big picture.

Jon

Edited by Jon Isaacs (02/14/13 06:55 AM)


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Damo636
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5678870 - 02/14/13 07:09 AM

Quote:




Save your pennies kiddies, grab yourself a few Pentax XW's while supplies on the used market lasts.





I did save my pennies and have just added the 5mm to the stall


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ROBERT FREE
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Damo636]
      #5678971 - 02/14/13 08:52 AM

i observe mercury an venus in broad daylite,an i have no problems with them as one does looking in twilite.a world of difference but like i said its been years an there are so many ep's out there but thx for the updates,an ill pick up 1 2 pentax.clear skies all.

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HTJ
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5679788 - 02/14/13 03:55 PM

Hi

I own XW7, XW10, Hyperion 17, and previously the Hyperion 8 mm.

In slow scopes, say f/9 and slower the Hyperions do pretty well, but they never get really good edge performance. They don't reach the sharpness and contrast levels of the XWs, but in slow scopes I find them acceptable. On f/6 and faster, don't bother with the Hyperions.

The XWs are truly great. Wide field, sharp, high contrast, no flaring, and great ergonomics. They make the viewing pleasant and relaxed. The XWs are for life.

I reguarly use my Hyperion 17 in my 100ED. It produces a good magnification for some DSO and creates an exit pupil just under 2 mm, which seems to work very well for me, and gives me a high perceived contrast. I also have the BGO18, which is sharper and probably has slightly higher throughput and contrast. But the Hyperion 17 has better ergonomics which means more eyepiece time. The wider field means less fiddling with my manual mount, which means even more eyepiece time.

I may get a LVW 17 or Delos 17 to replace the Hyperion 17 some time, but I am no rush for it (and I like buying eyepieces :-)).

With regards to the Hyperions and the ES82 line: I think the Hyperion has way better ergonomics than the ES82. However the ES82 is optically superior in all other ways (I've only had the ES82 8.8 mm though).

/Henrik


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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Damo636]
      #5679820 - 02/14/13 04:20 PM

Quote:

Quote:




Save your pennies kiddies, grab yourself a few Pentax XW's while supplies on the used market lasts.





I did save my pennies and have just added the 5mm to the stall




Trying to add the 10mm XW as we type.


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ROBERT FREE
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: HTJ]
      #5679833 - 02/14/13 04:23 PM

thx htj i just got the hyperion 8mm to try out.139.00 i want to see what its like vs my 25 year 30 year celestron ultimas which do the job but quite old. i can always return the 8 an get a pentax 8 279.00 costly but probably worth it.i have an 8" f-10

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Starman1
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5680150 - 02/14/13 08:12 PM

Quote:

thx htj i just got the hyperion 8mm to try out.139.00 i want to see what its like vs my 25 year 30 year celestron ultimas which do the job but quite old. i can always return the 8 an get a pentax 8 279.00 costly but probably worth it.i have an 8" f-10



The "TO", meaning "toward" in your signature line should read "TOO", meaning "too much", and the attribution should be to the poet Sarah Williams:
"Though my soul may set in darkness, it will rise in perfect light;
I have loved the stars too fondly to be fearful of the night."


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Scanning4Comets
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5680165 - 02/14/13 08:28 PM

Quote:

Trying to add the 10mm XW as we type.




I'm thinking about getting a 5mm XW even though I can barlow my 10mm XW, because I'd rather just plop a 5mm in instead of fiddling with a barlow!....Too bad they didn't make a 4.5mm XW as that would be better in my case!

And. NO, I don't want a 4.5mm Delos. I prefer the ergonomics of the XW's much more!

Cheers,


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Tank
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5680175 - 02/14/13 08:33 PM

Pentax XW are great i doubt the Baader Hyperion can hang with them but i bet the BGO can!
The 5,7,10 are awesome EPs just a bit expensive!
The reason i dont have then is because i have some exotic glass in those FLs
5 XO
7 Pentax SMC ortho .965
10 CZJ


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wirenut
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5680186 - 02/14/13 08:41 PM

Watch out robert, it's the literature/grammer police LOL they are coming to take you away!!! just kidding if it was me and my wife saw that, it wouldn't end till I fixed it.

I hope you enjoy your new EP I have found the best features of the hyperions are eye relief and AFOV. stars are pretty sharp to edge in my F6 scope. what I don't like about them is the background doesn't seem as dark or planetary images as crisp as with my plossls. I think that's contrast.


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Starman1
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Tank]
      #5680195 - 02/14/13 08:52 PM

Quote:

Pentax XW are great i doubt the Baader Hyperion can hang with them but i bet the BGO can!
The 5,7,10 are awesome EPs just a bit expensive!
The reason i dont have them is because i have some exotic glass in those FLs:
5 XO
7 Pentax SMC ortho .965
10 CZJ



Alas, the BGOs are no more, unless purchased used.
The BCOs (Baader Classic Orthos) are available only in 6, 10, and 18mm.
One hopes that more focal lengths will be avail. in the future.
In the meantime, Abbé orthos are available direct from Kasai, and from:
University Optics (some focal lengths), Edmund Scientific.
The PL Orthos from Carl Zeiss don't appear to be classic Abbé orthos though they are listed as othoscopic (meaning without distortion).


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FoxTrot
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5680225 - 02/14/13 09:17 PM

Robert, I reiterate the statements of the majority of those above, the answer is 'no'. I have a Pentax XW 7mm, and LVW 13mm and most recently a Orion Stratus 24mm (similar to the Baader line), and I've now had more time to evaluate the latter since I got it a few weeks ago. Notwithstanding these are all different focal lengths, the Pentax XW out classes the lot, by a long mile. Even in my f/5 fast refractors, the XW provides incredible distortion free control over the image. The LVW is not bad, but I can tell its not perfectly suited for my f/5 scopes. The Orion Stratus is nice for the price I got it for, but shows quite a degree of field curvature in my scopes. It cleans up better with barlowing. Completely subjective rating, but if the Pentax XW is 100%, the LVW would be 90% and the Stratus say a 60-70% - the difference is substantial in my book.

Now having said all that, I do rate the Stratus an excellent buy for the second-hand price I got it for ($100 AUD). Its a gift for a friend who has an Skywatcher 80ED and I have no doubt he will love the Stratus, given he only has bottom rung no brand plossls at the moment. The 68 deg wide view, great eye relief, and "reasonable" performance make it a good buy at this level.

Cheers, Fox


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Jon Isaacs
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: FoxTrot]
      #5680750 - 02/15/13 07:01 AM

Quote:

Even in my f/5 fast refractors, the XW provides incredible distortion free control over the image.




I know this might seem to be "picky, picky" but did you mean to say "aberration free control over the image" rather than "distortion free control over the image."

A distortion free field is one where the relation of of the stars to one another is correct, that is orthoscopic. With a 70 degree AFoV, distortion is unavoidable. An aberration free field means the stars are round and sharp across the field. Aberrations include field curvature, astigmatism and coma.

Jon


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FoxTrot
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5680808 - 02/15/13 08:09 AM

Quote:

Quote:

Even in my f/5 fast refractors, the XW provides incredible distortion free control over the image.




I know this might seem to be "picky, picky" but did you mean to say "aberration free control over the image" rather than "distortion free control over the image."

A distortion free field is one where the relation of of the stars to one another is correct, that is orthoscopic. With a 70 degree AFoV, distortion is unavoidable. An aberration free field means the stars are round and sharp across the field. Aberrations include field curvature, astigmatism and coma.

Jon



Thanks Jon, much more well put - 'aberration' free the XW 7mm certainly is.
Indeed, even comparing my Panoptic 27mm to the Stratus 24mm, the difference is startling as well; clarity, sharpness and brilliance of the image are miles ahead in the Panoptic. Definitely a case of ' you get what you pay for'.


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MRNUTTY
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5680876 - 02/15/13 08:51 AM

I bought the lot of XW's due to the productuon halt fear-factor of the XO's. I had heard great things about them, and I wasn't going to miss out on the remaining Pentax product line. It turned out to be the best EP purchase yet! They are the first thing into the trunk when I travel to my dark site :-) I haven't had enough time to compare them agrainst my Televue's yet, but based purely on popular vote it will be a neck-and-neck race all the way to the finish line. If I were to go through the whole purchase process again, I wouldn't get sidelined by bargain EP's again with the exception of the Seibert's; they have a charm all their own, and the Explore Sceintific 82 and 68's; stopping at them would be a no fault choice, and the Circle-T Ortho, Kelner and Erfle's; can't be beat by wieght alone :-)

Edited by MRNUTTY (02/15/13 12:28 PM)


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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: MRNUTTY]
      #5680921 - 02/15/13 09:09 AM

See Kids? See what happens when you look thru a telescope? Do you want to end up like this? Hi, my name is (insert name here), and I'm an Ocularholic. (But then, Hey, if you're gonna be one, be the best).

I even heard he donated an eye for his CollinsI3....


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MRNUTTY
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: csrlice12]
      #5681350 - 02/15/13 12:29 PM

It was my third eye :-)

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Jon Isaacs
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: FoxTrot]
      #5681393 - 02/15/13 12:47 PM

Quote:

Indeed, even comparing my Panoptic 27mm to the Stratus 24mm, the difference is startling as well; clarity, sharpness and brilliance of the image are miles ahead in the Panoptic. Definitely a case of ' you get what you pay for'.




It is my understanding that of all the Stratus/Hyperion line, the 24mm is the weakest. For a while I had the 13mm Stratus. At the same time I had the 16mm Type 2 Nagler. At night, it is easy to mistake the Stratus 13mm for the 16 mm Nagler and vice versa, they are similar is size, shape and weight. I made many side by side comparisons, essentially blind.

When I mistook the 16mm Nagler for the 13mm Stratus, my reaction was always the same. For a few seconds I would remark to myself that the Stratus was really quite a good eyepiece with none of the bright edge and off-axis aberrations I had remembered. The field of view was sharp and evenly illuminated from the center to the edge.

After a moment of admiration, I realized, "This is the 16mm Nagler, not the 13mm Stratus."

Jon


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Scanning4Comets
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5681503 - 02/15/13 01:28 PM

Quote:

I know this might seem to be "picky, picky" but did you mean to say "aberration free control over the image" rather than "distortion free control over the image."

A distortion free field is one where the relation of of the stars to one another is correct, that is orthoscopic. With a 70 degree AFoV, distortion is unavoidable. An aberration free field means the stars are round and sharp across the field. Aberrations include field curvature, astigmatism and coma.

Jon




Jon, where do you get this notion that distortion is unavoidable in some 70 degree eyepieces? There is zero distortion in my 10mm and 7mm Pentax XW's. I have said this for years. Pinpoint stars across the field in both.

Cheers,


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photiost
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5681507 - 02/15/13 01:29 PM

Quote:

Color filters definitely improve the view of Mercury, both by filtering out the brightness of the sky in which the planet is usually viewed, and by reducing the chromatic issues with the lower atmospheric viewing of the planet.
My records show:
Effective at sharpening: #25 red, #23A red-orange
Effective at seeing albedo markings: #15 deep yellow, #12 Yellow
The "in-between" filter: #21 orange.




Personally I have found Mercury is best observed when in the morning sky.

Find Mercury then track it until it comes up higher on the horizon. Yes the background sky is brighter but the atmosphere is "steadier" and the planets disk is also clearer -

Using Filters also helps.

.


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russell23
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5681531 - 02/15/13 01:41 PM

Quote:

Quote:

I know this might seem to be "picky, picky" but did you mean to say "aberration free control over the image" rather than "distortion free control over the image."

A distortion free field is one where the relation of of the stars to one another is correct, that is orthoscopic. With a 70 degree AFoV, distortion is unavoidable. An aberration free field means the stars are round and sharp across the field. Aberrations include field curvature, astigmatism and coma.

Jon




Jon, where do you get this notion that distortion is unavoidable in some 70 degree eyepieces? There is zero distortion in my 10mm and 7mm Pentax XW's. I have said this for years. Pinpoint stars across the field in both.

Cheers,




Markus,

What Jon is saying is that there is a difference in the meaning of the words "distortion" and "aberration". He even defines them in his post. The Pentax XW's are not free from "distortion" meaning that the stars do not maintain the same relation across the entire field. You may see this if you adjust the position of a grouping of stars to different points in the FOV. What Jon is saying is that an eyepiece can present pinpoint sharp stars across the field and still have distortion.

Dave


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Mark9473
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5681538 - 02/15/13 01:43 PM

Quote:

Jon, where do you get this notion that distortion is unavoidable in some 70 degree eyepieces? There is zero distortion in my 10mm and 7mm Pentax XW's. I have said this for years. Pinpoint stars across the field in both.




Well, pin-point stars is not a test for distortion but for aberration. Distortion shows itself as straight lines becoming curved, or the Moon becoming oblong, or the magnification changing at the edge.


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photiost
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5681652 - 02/15/13 02:25 PM

Quote:


It is my understanding that of all the Stratus/Hyperion line, the 24mm is the weakest. For a while I had the 13mm Stratus. At the same time I had the 16mm Type 2 Nagler. At night, it is easy to mistake the Stratus 13mm for the 16 mm Nagler and vice versa, they are similar is size, shape and weight. I made many side by side comparisons, essentially blind.

When I mistook the 16mm Nagler for the 13mm Stratus, my reaction was always the same. For a few seconds I would remark to myself that the Stratus was really quite a good eyepiece with none of the bright edge and off-axis aberrations I had remembered. The field of view was sharp and evenly illuminated from the center to the edge.

After a moment of admiration, I realized, "This is the 16mm Nagler, not the 13mm Stratus."

Jon




I have the complete set of Hyperions (5mm to 24mm) and use them on my 15in f5 Reflector with no issues.

They are good eyepieces and for the price you cant go wrong.

On a side by side the Hyperion 10mm vs Pentax 10mm XW (on Saturn and M13) the Pentax is a better eyepiece (overall) however the Hyperion was not a pushover.
.


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howard929
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5681659 - 02/15/13 02:26 PM

Quote:



I know this might seem to be "picky, picky" but did you mean to say "aberration free control over the image" rather than "distortion free control over the image."

A distortion free field is one where the relation of of the stars to one another is correct, that is orthoscopic. With a 70 degree AFoV, distortion is unavoidable. An aberration free field means the stars are round and sharp across the field. Aberrations include field curvature, astigmatism and coma.

Jon




This may be moot and just theoretical but isn't that curvature due to AFOV and eyepiece format size? For instance, wouldn't a 70 degree 12mm 2" eyepiece be capable of displaying less curvature then the same in 1.25"?


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5681790 - 02/15/13 03:33 PM

Quote:

Jon, where do you get this notion that distortion is unavoidable in some 70 degree eyepieces? There is zero distortion in my 10mm and 7mm Pentax XW's. I have said this for years. Pinpoint stars across the field in both




Distortion doesn't mean that the image is out of focus and the stars not sharp. Distortion is about the shape of the image. Let's say we observe a square object, such as a window. The telescope has a flat field and so does the eyepiece. Every point in the image is in sharp focus.

If the eyepiece has linear distortion, the square will now be shaped with its sides bowing inwards (pincushion distortion, most common), or with its sides bowing outwards (barrel distortion, more unusual).

But an eyepiece CAN actually have zero distortion, but it will then have angular distortion, which means its magnification will vary from center to edge.

It is mathematically and physically impossible to correct an eyepiece for both linear and angular distortion at the same time. Most eyepieces for astronomical observing tries to correct as fully for angular distortion as possible and leave linear distortion as it is.

http://www.telescope-optics.net/eyepiece_aberration_2.htm


Clear skies!
Thomas, Denmark

Edited by Astrojensen (02/15/13 03:33 PM)


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Starman1
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5681847 - 02/15/13 03:58 PM

From my website regarding aberrations in eyepieces (I note there might be some confusion between Field Curvature and rectilinear distortion, so I hope this may prove useful):

ABERRATIONS

1. Chromatic Aberration. This is essentially two different aberrations, but with similar effects, so I include them together, here. Eyepieces are made with lenses, and as such do not focus all colors at exactly the same point or with the same resolution. It is a very poor eyepiece that displays “blur circles” of different sizes for different colors on axis, but it is not at all uncommon for even excellent eyepieces to do so at the edge of the field. Center-of-field chromatic aberration is usually caused by having too few elements to correct for light’s tendency to have different wavelengths refract differently when passing through glass. Sometimes, lateral chromatic aberration is chosen as the “lesser of two evils” when correcting a nasty edge-of-field aberration that may be worse. Chromatic aberration can express itself as a color fringe to a bright object like a star or the edge of the Moon (chromatic aberration of the first type), or it can express itself as a slight prismatic effect seen when viewing sideways through the eyepiece, usually on the edge-of-field objects (chromatic aberration of the second, or lateral, type). This latter issue is often described as “lateral color”, but is a form of chromatic aberration that has its source in lateral distortion that changes with frequency. Also, if an eyepiece design is created to correct for color up to a lateral field size of, say, 50 degrees, but is created with a 60 degree field, that final 10 degrees of field may display color beyond the parameters of the designer, sometimes unpredictably. Daytime use will often show the extent of the problem easier than any nighttime viewing (except, perhaps, on the Moon). Some early eyepiece designs, such as Ramsden, Huyghens, or Kellner, do not correct well for either type of chromatic aberration, and should be avoided.

2. Field Curvature. Most telescopes’ final focal plane is curved—that is, the focal plane is convex or concave toward you and slightly curves as the field of view widens. Fortunately, this curvature is very slight in the narrow fields we observe through the telescope. Nonetheless, it is there. Eyepieces can have either negative (concave toward you) or positive field curvature depending on their designs, and this brings into play the idea of a telescope-eyepiece interaction that points out that eyepieces will perform differently in different scopes. If the negative curvature of the eyepiece matches the positive curvature of the telescope exactly, likely in flatfield telescopes, this can result in a perfectly flat field of view through the eyepiece through cancellation. Neither the eyepiece nor the telescope is perfect—merely the interaction between the two. This is why evaluating field curvature in an eyepiece is merely a statement of how the curvature appears in your scope [note: long focal length reflectors display almost no curvature]. There may be other telescopes in which the eyepiece does not present the same field curvature (though the differences will be slight). Field curvature is seen as a defocusing of the star images at/near the edge of field. If further infocusing (racking the focuser toward the objective) focuses the stars at the edge, then the field curvature is positive. If outfocusing is necessary, then the curvature is negative. Young people, whose eyes can accommodate more focal differences than older people, will be bothered less by this aberration. Ideally, if an eyepiece has no field curvature, all that will display is the very slight curvature from the scope itself, which is highly unlikely to be visible. Note that this is NOT the same aberration that causes a feeling of “looking through a fishbowl” when panning the scope.

3. Angular magnification distortion. This is where the magnification factor at the edge of the field is not the same as it is in the center. I see this all the time in well corrected binoculars, and it is there as a side-effect of correction for rectilinear distortion in wider fields of view (I’ll discuss this next). In an astronomical usage, this is not usually a severe aberration (unless completely uncorrected), but it does play havoc with trying to figure out what the apparent field or true field of an eyepiece is. The speed with which an object will drift across the FOV in an undriven scope would not be linear, but change with distance from center. This can result in a star-drift timing (to determine the true field of view) that results in a true field that cannot be derived from the apparent field quoted for the eyepiece. As an extreme case, picture sitting in space and watching a city on the Earth as it first appears on the limb, then traverses the disc and finally exits the view. It will move fastest when moving across the center, yet slowly when entering and exiting the FOV. A timing of the passage would lead you to calculate a wider field for the image of the Earth than actual. As a comparison, this would mean, in an eyepiece, that the true field of view is wider than the apparent field would calculate. And the reverse can be true as well. Fortunately for us, this distortion is usually small in eyepieces (though ultrawidefields could and would have more of this unless specifically corrected). Most star drift timings of true field result in only small discrepancies from the apparent field predictions of true field. In a telescope, a completely uncorrected angular magnification distortion will result in different spacings of details in objects as they approach the edge of the field.

4. Rectilinear distortion. This is the distortion at the edge of the field that causes straight lines to bow in toward the center (called pincushion distortion) or bow out away from the center (called barrel distortion). It is usually unnoticeable in star fields, and is often tolerated to correct for astigmatism and angular magnification distortion, aberrations much more easily seen. It does mean that the geometric arrangement of the stars in a field of view will be different at the edge of the field than in the center, but this is easily tolerated. This is a horrible aberration for an eyepiece in binoculars, when used on land objects in the daytime, but is no big deal in an astronomical setting. However, people who pan their scopes back and forth often get nauseated by the “passing through a fishbowl” effect this can cause in the field of view. If your usage involves a lot of scanning of the skies, this may be an aberration you won’t want to tolerate. For most of us, though, it is so hard to see that it is quite preferable to astigmatism, the aberration it is designed to hold in check. In ultrawide fields of view, this aberration is present when angular magnification distortion is corrected. If corrected, angular magnification distortion will be present. These two aberrations cannot be simultaneously corrected in widefield eyepieces. Lucky for us, the eye will see distortion at the edge of a field unless there is some rectilinear distortion present, so eyepieces specifically designed for astronomy often leave this aberration in place and correct angular magnification distortion instead.

5. Astigmatism. This is caused by the vertical (sagittal) curvature of the eyepiece field being different that the horizontal (tangential) curvature of the eyepiece field. That this is tolerated at all is due to the fact that not all forms of distortion can be corrected at once. If you want low rectilinear distortion, some astigmatism may appear (and the converse, as I previously mentioned). This, in daylight use, causes a defocusing/blurring of the edge of the field of view. At night, it causes the stars at the edge of the field to appear as short radial lines on one side of focus, and short circumferential lines on the other. In focus, the star images may appear slightly blurry (center) or appear like seagulls or bats (at the edge, when combining with other aberrations). This is the most prevalent problem with inexpensive widefield eyepieces, and is worse when the focal ratio of the telescope is short (say, f/3-f/5). Astigmatism can also be caused by tilted elements in the eyepiece housing, or wedge (faces of lenses not in same axial lineup), or miscollimation of the optical axis with the axis of the focuser. It can also be caused by an interaction of the eyepiece design with the astigmatism of the telescope’s objective or the improper tilt of a mirror, which is why we are looking for an aberration that is equal in all directions from center in the FOV, where the eyepiece is concerned.

6. Spherical aberration. With multiple elements, this would seem to be tightly controlled in eyepieces, yet it can be an issue. This would manifest itself as different parts of the axial ray (or all rays, for that matter) coming to focus at different places. The result is a blurred image (one that doesn’t focus well or seems to have a long range of best focus) that cannot be sharply focused. I will state that the amount of this present in eyepieces is so small compared to the objectives that, to all intents and purposes, it is not there. What tiny amounts are present would largely go unnoticed.

7. Spherical aberration of the Exit Pupil. This is found in some eyepieces and is described as having different parts of the eyepiece’s eye relief dimension be different depending on the point in the field of view. How you would see it is that at different distances away from the eyepiece, you would see the outer edges of the field, or the center, or one edge or the other, but not at the same time. The field of view would appear to have kidney bean-shaped dark areas drifting around the field, depending on where you were holding your eye. There would be only one position for the eye that would result in most of the field of view being visible and in focus at the same time, and you might have to rock your head from side to side to see the edges of the field, one after the other. In essence, the exit pupil of the eyepiece, instead of being a small, circular plane, is a curved surface, usually curving away from the eye in all directions from center. The original Nagler Type 1 eyepieces, especially the 13mm, displayed this aberration, and the correction for it was the genesis of the Nagler Type 2. Most of the other eyepieces exhibiting this characteristic are long focal length eyepieces, or eyepieces with long eye reliefs, though it should be noted that blackout problems with an eyepiece do not necessarily indicate spherical aberration of the exit pupil. It can also indicate the viewer is holding his eye too close to the eyepiece.

8. Transmission anomalies by wavelength. This is exemplified by an eyepiece’s not transmitting all wavelengths of light with equal intensity. At best, it means a light rolling off of transmission at the extremes of the visual spectrum. At worst, it means a noticeable tint in the field of view, especially on the Moon. This is an aberration in all eyepieces. The difference is only in severity or noticeability.

9. Vignetting. This is a loss of edge brightness (transmission anomaly by distance from center) due to improper lens diameters (one element unable to field the entire set of rays from the preceding one), barrel diameter (too small an internal diameter to pass all edge-of-field rays), or simply normal design (a 40mm eyepiece in a 1-1/4” barrel will vignette rays at the edge so that, regardless of lens diameter, the field of view will be truncated by the barrel’s entrance diameter). The causes of vignetting, where it is described as being due to the size of the secondary mirror or telescope opening aperture, is really a sub-optimal relationship of the field of the eyepiece and the telescope’s focal plane. It is not the eyepiece that is vignetting, in that case, but the use of too large an eyepiece for the telescope’s illuminated field. Vignetting in an eyepiece is harder to see, and can often be seen only by holding the eyepiece up to a bright sky and looking at the edges of the field. If it noticeably darkens at the edge, there is vignetting involved. If it doesn’t noticeably vignette, it could still be there in lab tests, but is unlikely to cause problems in viewing.

10. Coma. Yes, eyepieces can have coma. It is the same as coma in a short focal length lens or mirror, but is significantly smaller in quantity. It expresses itself, usually, as a radial unsharpness in the star images, as they move from center to edge, that gets gradually worse toward the edge. Because astigmatism is likely to be more severe and more noticeable, I am not sure how you would tell the eyepiece has coma other than by ray-tracing the design. It might be possible to notice it in a completely flat-field telescope that lacks coma (f/30 refractor?), but in the real world, coma is 99.99% an issue with the primary objective. Very simple designs can exhibit coma, but you are staying away from these, aren’t you?

11. Light loss. This can be caused by back reflection from lens surfaces, absorption by the lens elements (lack of transparency or tint), scatter from the lens surfaces causing destructive interference in the wavefront, and internal vignetting. I usually talk about each of these issues separately, but I lump them together as light loss. Ultimately, the reach of your telescope is dependent on the maximum transmission of each element. The eyepiece is merely a link in the chain.

12. Wavefront aberrations. This is similar to the problems caused by an inaccurate mirror surface, except that an eyepiece has many such surfaces. The reduction in the quality of the final image can come from poor polish on the lens surfaces (+/- wavelength %), poor figure (the lack of correspondence of the surface curves to design parameters—like the Hubble, originally), or an increase in the number of surfaces. This is where fewer elements can be better. Unless the surfaces are all perfect (and that is HIGHLY unlikely), the more surfaces there are the more likely the final image’s quality is likely to be reduced by these aberrations. Unfortunately, one manufacturer’s 8-element eyepiece may have a final wavefront that is more accurate than another manufacturer’s 3-element eyepiece, so we are truly generalizing when we say fewer elements are better. In specific, this may not be true.

13. Loss of contrast due to light scatter. This is not, technically, an aberration, yet it is a problem in eyepieces that causes a diminution of the final image quality. It is caused by light scatter due to poorly polished optical surfaces, lens reflections due to edge-of-lens reflection, lens reflections due to poorly applied or absence of coatings, low angle-of-incidence scattering from the lens coatings, and shiny internal surfaces in the barrels and baffles. It is exemplified by a “graying out” of the background sky in a given eyepiece. Since larger apertures and/or lower powers show lighter background skies, the only way to really tell about the presence of this one is to compare another eyepiece of exactly the same field of view and focal length, or to put a bright object just outside the field of view and see if you can detect any internal evidence of the direction in which the bright object lies. Ideally, if a bright object leaves the field, there should be no visible evidence of its direction left in the field except diffraction spikes. Likewise, there should be no halo around any object, no matter how bright, that changes the darkness of the background sky around the object. In practice, many such problems are caused by the eye, or dirt or dew on the optics, or haze in the sky, so steps should be taken to minimize those issues before any form of evaluation. Ideally, this is one that should be measured on a test lab’s bench, but we don’t have access to such data as of yet. It needs to be noted that a bright object in a reflector telescope may have bright spikes emanating from the star or object, and these spikes may be visible until the object leaves the field of view of the telescope, which will be larger than the field of view of the eyepiece. This is not the form of light scatter to which I refer.

14. Thermal issues. If an inadequate clearance is left between the housing and the internal lens elements, as the barrel shrinks it may squeeze and/or bend the internal elements. This is more likely to be a problem in larger eyepieces, where the temperature differential between the housing and the internal elements is likely to be the highest. Big eyepieces like the 31mm Nagler have to come to thermal equilibrium, just like telescope objectives, in order to give their best images. Fortunately, the eyepiece will be at equilibrium before the mirror. This is a valid reason NOT to carry the eyepieces in a coat pocket or to store them in a closed case until used. In places where dew is a problem, the eyepiece may have to be maintained at a warmer temperature. That isn't optimum, but it's preferable to fogging or even frosting of the eyepiece.

15. Design flaws in the eyepiece. I’ve lumped these together, even though it is several issues. They are indicative of qualitative issues with the eyepiece design, and can indicate why you may not want to buy any of said eyepieces. Examples:

---- Field stop not in focus (improperly placed field stop results in vague field edge).

---- Wrong refractive index of glass used, resulting in aberrations not in the original design—this can be true of later versions of an earlier design.

---- Critical f/ratio too high—wherein the eyepiece manufacturer designed the eyepiece to adequately field the narrow light cone of an f/15 refractor (for example), but not an f/4.5 reflector. Personally, I think all eyepieces should be designed to handle the wider f/4 light cone well. Why should we have to become aware of which eyepiece does or does not work in our f/4.5 reflectors? This is a problem with many companies, unfortunately.

---- Improper internal design, leading to vignetting or internal reflections. These are issues easily addressed, yet so many eyepieces do not. It may mean a poor optical design, a poor manufacturer, or too tight a budget to produce a good eyepiece. Whatever the reason, this is a good reason to eschew the purchase and use of these eyepieces until the problems are solved.

I’ve been very liberal in my use of the word aberration to include any deviation from a perfect image at the exit pupil of the eyepiece. It must be noted that these aberrations, though real, detract less, usually, from the final image quality than do the grosser aberrations of the primary mirrors and lenses. One should address, in designing the optimum optical system for one’s budget, the quality of the mirrors and eyepieces together, for, ultimately, it is the combination of these elements that produces the final image.

How are we, in the absence of test-lab data, to come to any conclusion about the quality of any one of the over 1000 eyepieces currently on the market? Go to star parties. Ask users their opinions about their eyepieces. Read Cloudy Nights. Read on-line reviews. Read magazine reviews. Read books on the subject of telescope optics. Test for yourself by experimentation. Maybe some day we’ll get quantified lab tests. Until that day, just be aware that there is no perfect eyepiece—merely ones that are good enough for you.


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ROBERT FREE
sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: howard929]
      #5681859 - 02/15/13 04:06 PM

ACTUALLY mercury is best seen about 2-4 pm when its at its zenith.been looking at vensu an mercury in daylite for 40 years.an orange 21 an lite red filter works the best.right now it looks great at 3.45 est.

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ROBERT FREE
sage
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: howard929]
      #5681867 - 02/15/13 04:10 PM

actually i find the best views of merc n venus in daylite at about 2-4 oclock in aft when there at there zenith an less atmosphere to go thru,though am is ok at times to.been doing this for 40 years.clear skies

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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5681880 - 02/15/13 04:16 PM

Don, that was a fantastic summary on eyepiece aberrations.


Clear skies!
Thomas, Denmark


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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5681896 - 02/15/13 04:25 PM

Don: THANK YOU for the in-depth explanations of the various terms. This is really helpful information.

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coutleef
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Astrojensen]
      #5681898 - 02/15/13 04:27 PM

thanks Don it is all there

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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: coutleef]
      #5681930 - 02/15/13 04:43 PM

WOOOHOOOO, my Pentax 10XW just arrived!!

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jrbarnett
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5681936 - 02/15/13 04:46 PM

NO.



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Starman1
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DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: jrbarnett]
      #5681992 - 02/15/13 05:15 PM

I'm glad that so many people enjoy the Pentax XWs, so it seems that someone needs to be a (slight) contrarian here.

I don't think that they are anastigmatic, because I see some residual astigmatism in each of the focal lengths I've tried (I haven't used the now defunct 40mm and the still current 5 and 3.5mm). I suspect that most do not evaluate the edge-of-field images that closely or that they don't have other, anastigmatic, eyepieces on hand to compare them with.

Don't get me wrong, because they are very good eyepieces, and i could live with them. But with all the cheerleading going on, someone has to point out they aren't perfect, just very good.

Edited by Starman1 (02/15/13 05:17 PM)


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LivingNDixie
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5682023 - 02/15/13 05:30 PM

Quote:

I'm glad that so many people enjoy the Pentax XWs, so it seems that someone needs to be a (slight) contrarian here.

I don't think that they are anastigmatic, because I see some residual astigmatism in each of the focal lengths I've tried (I haven't used the now defunct 40mm and the still current 5 and 3.5mm). I suspect that most do not evaluate the edge-of-field images that closely or that they don't have other, anastigmatic, eyepieces on hand to compare them with.

Don't get me wrong, because they are very good eyepieces, and i could live with them. But with all the cheerleading going on, someone has to point out they aren't perfect, just very good.




Other then field curvature in a couple of models, they are about as close to perfect you can get.


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RGM
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5682301 - 02/15/13 08:36 PM

Quote:

I'm glad that so many people enjoy the Pentax XWs, so it seems that someone needs to be a (slight) contrarian here.

I don't think that they are anastigmatic, because I see some residual astigmatism in each of the focal lengths I've tried (I haven't used the now defunct 40mm and the still current 5 and 3.5mm). I suspect that most do not evaluate the edge-of-field images that closely or that they don't have other, anastigmatic, eyepieces on hand to compare them with.

Don't get me wrong, because they are very good eyepieces, and i could live with them. But with all the cheerleading going on, someone has to point out they aren't perfect, just very good.




I am another XW fan. I do agree they may not be perfect, but to my 60 year old eyes, it does not get better. No eyepiece I have owned puts up a better view. I do have issues with the 14XW, but still use it more often than my 17NagT4 or 13NagT6.


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Jon Isaacs
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5682390 - 02/15/13 09:26 PM

Quote:

anastigmatic




Don:

I guess this is my thread to be "picky, picky."

It seems to me that a system that is free from astigmatism would be "stigmatic" rather than "anastigmatic" since astigmatic actually means "not-stigmatic."

Stigmatic means that a point focuses to a point.

Wikipedia: Stigmatism

Jon


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Starman1
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Jon Isaacs]
      #5682403 - 02/15/13 09:34 PM

an·as·tig·mat·ic
adj.
Free from astigmatism. Used of a compound lens in which the separate components compensate for the astigmatic effects of each lens.

I was merely using the word commonly used to mean "without astigmatism".

2nd definition:
anastigmatic
adj
(Physics / General Physics) (of a lens or optical device) not astigmatic Also stigmatic.


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Scanning4Comets
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5682442 - 02/15/13 10:02 PM

Quote:

I'm glad that so many people enjoy the Pentax XWs, so it seems that someone needs to be a (slight) contrarian here.

I don't think that they are anastigmatic, because I see some residual astigmatism in each of the focal lengths I've tried (I haven't used the now defunct 40mm and the still current 5 and 3.5mm). I suspect that most do not evaluate the edge-of-field images that closely or that they don't have other, anastigmatic, eyepieces on hand to compare them with.

Don't get me wrong, because they are very good eyepieces, and I could live with them. But with all the cheer-leading going on, someone has to point out they aren't perfect, just very good.




I've looked extensively at the edges of the 10mm and 7mm XW using bright stars and planets. Stars remain aberration-free all over the board in both...to my eyes. I have also let Saturn and Jupiter drift right to the edges and in looking I can see no distortion at all in both cases.

Now, I am not saying that I do this all of the time as I *DO* keeps things centered all of the time. I am just stating a fact here. I have compared Pentax eyepieces to some others, and they are a far cry from just being "very good." No "cheer-leading" going on here, just facts from real observing sessions in many different seasons.

cheers,


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jrbarnett
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5682528 - 02/15/13 10:56 PM

I like the XWs better than the Hyperions and better than the NAV-SWs, but...

I like the LVWs better than the XWs.

So no, no perfect eyepieces. But the question wasn't whether the XWs are perfect, but rather whether the Hyperions are close to the XWs. Hence my answer - most certainly NO!

- Jim


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george tatsis
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Re: DO BAADER HYPERIONS COME CLOSE TO PENTAX XW new [Re: Starman1]
      #5682618 - 02/15/13 11:52 PM

Quote:

I'm glad that so many people enjoy the Pentax XWs, so it seems that someone needs to be a (slight) contrarian here.


Don't get me wrong, because they are very good eyepieces, and i could live with them. But with all the cheerleading going on, someone has to point out they aren't perfect, just very good.






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ibase
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: photiost]
      #5682754 - 02/16/13 02:12 AM

Quote:


..Hyperions (5mm to 24mm) and use them on my 15in f5 Reflector with no issues.

They are good eyepieces and for the price you cant go wrong.

On a side by side the Hyperion 10mm vs Pentax 10mm XW (on Saturn and M13) the Pentax is a better eyepiece (overall) however the Hyperion was not a pushover.
.




+1 Hyperions are good values (especially on the C8 F/10) and have been popular for some time. Pentax belongs to the upper-tier in terms of optical performance and build, a step-up from Hyperions, and also worth saving for. All depends on how much $ one is willing to pony up. FWIW I had a Pentax XW7 and traded it for a Delos 6mm, and am a happy camper with the Delos.

Best,


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Arizona-Ken
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ibase]
      #5683106 - 02/16/13 10:03 AM

Hyperions were the darlings of this forum about 3 or 4 years ago for a modestly priced eyepiece. Now they have largely been supplanted by the ES eyepieces.

In my eyepiece journey I collected the 8mm, 13mm, 17mm, 21mm, 24mm, 31mm, and 36mm. In a f/10 SCT or a f/7.5 refractor they give great views.

I have since upgraded my eyepiece stable to include XWs, Panoptics, and a Nagler. These eyepieces give better views, but the Hyperions are great for 1/2 to 1/3 the price.

The advantage Hyperions still have over other similarly priced eyepieces is the performance with a 20 mm eye relief at all lengths. If you're an eyeglass wearer or just enjoy that longer eye relief, they still are a great choice for something between $100-$200.

Arizona Ken


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JayinUT
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Arizona-Ken]
      #5683519 - 02/16/13 01:22 PM

I have own the 5mm Hyperion, the 8mm & 13mm Stratus, the 17mm & 21mm Stratus which are very close to the Hyperions. I enjoyed them and used them extensively for several years. I've moved on to the Pentax XW's in the 5mm, 7mm, 10mm and 14mm lenses. No, the Hyperions do not match the quality and view of the Pentax XW's. I then have a 27mm Panoptic that is my wide field finder, a 30mm Explore Scientific 82 degree EP that is my speciality wide field lens and I also own a 24mm ES 82 degree (just did a comparison vs the 27mm Panoptic on my blog) and a 20mm ES 68 degree.

Anyway, I find I use the 27mm Panoptic, the 20mm ES 68 and the 30mm ES 82 the most in that order. I may end up selling the 24mm ES 82 as I prefer the 27 Pan to it.

My point is if money is a concern, and you want good eye relief then the Hyperion's would serve and I would recommend them in the 5mm, 8mm (take your pick, you'll probably use the 8mm more than the 5mm) and the 13mm. Then the 21mm could be a finder. Or you could go with say the 8mm and the 13mm and then go with 24 ES 68 degree if they ever come back in stock. IF eye relief is not a concern than the Explore Scientific eyepieces would save you some money (for some) and provide a better view IMO. YMMV.

IF money isn't an issue, then go with the Pentax eyepieces. I started out with what I thought I could afford and then eventually moved up to the eyepieces I wanted in the Pentax. Many times I wish I had just bit the bullet so to say up front and got what I really wanted and had been done with buying and selling eyepieces. Plus I would have gotten grief only one time from the wife, not four or five times of "Your buying MORE eyepieces again? Don't you have enough?" Sometimes spouses just never understand the equipment thing.

Edited by JayinUT (02/16/13 01:25 PM)


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Scanning4Comets
Markus
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: JayinUT]
      #5683803 - 02/16/13 04:10 PM Attachment (17 downloads)

Think I have finally figured out what is going on with the 10mm and 7mm XW's in my scope! The negative FC in these eyepieces, (as seen on the Pentax XW graphs), go good with the positive FC in my scope cancelling everything out to show what "appears" to be a flat field!

Throw me a cookie now, I'll be good to go.

BTW, I just bought a 5mm Vixen LVW to add to the eyepiece family !!!

cheers,


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Astrojensen
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5683814 - 02/16/13 04:14 PM

Quote:

This I have finally figured out what is going on with the 10mm and 7mm XW's in my scope! The negative FC in these eyepieces, (as seen on the Pentax XW graphs), go good with the positive FC in my scope cancelling everything out to show what "appears" to be a flat field!






Exactly!


Clear skies!
Thomas, Denmark


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GeneT
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: ROBERT FREE]
      #5686022 - 02/17/13 09:40 PM

No.

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GeneT
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Arizona-Ken]
      #5686027 - 02/17/13 09:43 PM

Quote:

Hyperions were the darlings of this forum about 3 or 4 years ago for a modestly priced eyepiece. Now they have largely been supplanted by the ES eyepieces.

In my eyepiece journey I collected the 8mm, 13mm, 17mm, 21mm, 24mm, 31mm, and 36mm. In a f/10 SCT or a f/7.5 refractor they give great views.

I have since upgraded my eyepiece stable to include XWs, Panoptics, and a Nagler. These eyepieces give better views, but the Hyperions are great for 1/2 to 1/3 the price.

The advantage Hyperions still have over other similarly priced eyepieces is the performance with a 20 mm eye relief at all lengths. If you're an eyeglass wearer or just enjoy that longer eye relief, they still are a great choice for something between $100-$200. Arizona Ken




Very well put!


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chboss
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: GeneT]
      #5686040 - 02/17/13 09:49 PM

Markus

Let us know what you think about the optical quality after the first light.
Might be an option to round out my arsenal at the high end of magnification.

best regards
Chris


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Scanning4Comets
Markus
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: chboss]
      #5686053 - 02/17/13 09:58 PM

Will do Chris!

Next time I get out, (after these really cold temps go away), I'll be out there checking on Jupiter, some DSO's and a few other targets. I'll come back here after doing so and let you know what the 5mm Vixen LVW is like!

I have so many favorites here on CN, that I can no longer add this one, so I bookmarked this page,

Cheers,


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chboss
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Scanning4Comets]
      #5686116 - 02/17/13 10:40 PM

Come to think maybe a new thread would be in order for a proper introduction since the original topic is about Hyperion vs. Pentax XW?

regards
Chris


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TexasRed
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: chboss]
      #5686407 - 02/18/13 04:09 AM

Ah, but do the Pentax eyepieces have the eye relief of the Hyperions?

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coutleef
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: TexasRed]
      #5686709 - 02/18/13 10:01 AM

Quote:

Ah, but do the Pentax eyepieces have the eye relief of the Hyperions?




they do with 20mm ER


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russell23
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: TexasRed]
      #5686760 - 02/18/13 10:35 AM

Quote:

Ah, but do the Pentax eyepieces have the eye relief of the Hyperions?




Yes - lots of eyepiece lines have the same 20mm of eye relief as the Hyperions:

Pentax XW's
TV Delos
TV Radians
Meade HD-60's
Celestron X-cel LX
Astrotech Long Eye Relief

Dave


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Darren Drake
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: russell23]
      #5692553 - 02/21/13 11:23 AM

Well I have the 17mm Hyperion and when I use it with a paracorr II in my f/4.4 I love the resulting image. The nice ER and sharp field stop and as I recall sharply defined stars near the edge make for a winner for me. I am surprised to hear from others that they are not at the level of the XWs but will do more investigating this observing season as I will have access to many of the Stratus eyepieces which are similar to the Hyperions.

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Starman81
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Darren Drake]
      #5692868 - 02/21/13 02:29 PM

Quote:

Well I have the 17mm Hyperion and when I use it with a paracorr II in my f/4.4 I love the resulting image. The nice ER and sharp field stop and as I recall sharply defined stars near the edge make for a winner for me. I am surprised to hear from others that they are not at the level of the XWs but will do more investigating this observing season as I will have access to many of the Stratus eyepieces which are similar to the Hyperions.




The 17mm might be the special case among the Hyperions; due to the sharp field stop you are not left straining to see edge of field. I first-lighted my 17mm Hyperion in a short session last week and the ergonomics and comfort were reminiscent of Pentax XW's, just very nice to use in the f/6 dob. If the rest of the line were the same, they would be a much more compelling choice for a lower-cost line of wide fields with 20mm ER.


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hfjacinto
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Starman81]
      #5692874 - 02/21/13 02:35 PM

I used to own several of the Hyperions. IMO the 13MM and the 17MM were the best of the group. The 24MM was the worst while the 21MM was good on some scopes and not so good on others. If you own an SCT and need 20MM of eyerelief I would recommend the Hyperions. But being honest the ES 82* are sharper to the edge and better overall (except for eye relief)

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Darren Drake
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: hfjacinto]
      #5692898 - 02/21/13 02:51 PM

Has anyone ever done a detailed comparo of the 17 Hyperion to the 17 Delos? Also I wonder if the field curvature issue with a 20XW would sway someone enough to go with a 17 Hyperion (although not quite the same fl)instead of the XW...

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cjc
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Darren Drake]
      #5692954 - 02/21/13 03:31 PM

I found that the 17mm Hyperion compared quite well with the 16mm ES68 in terms of view, but ergonomically they are very different. The ES is small and light, so much nicer to handle and more convenient being (just about) parfocal with my other (mainly ES) eyepieces.

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MRNUTTY
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Darren Drake]
      #5692959 - 02/21/13 03:36 PM

Quote:

Has anyone ever done a detailed comparo of the 17 Hyperion to the 17 Delos? Also I wonder if the field curvature issue with a 20XW would sway someone enough to go with a 17 Hyperion (although not quite the same fl)instead of the XW...




Hi Darren, a better replacement for the 20m XW will be a Delos 17mm. Hyperions, although good, are not up to the same league as these guys.


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csrlice12
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: MRNUTTY]
      #5692997 - 02/21/13 03:55 PM

Yes, but then the Pentax's go "Boo" and the Hyperions run away as fast as they can.........

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Darren Drake
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: MRNUTTY]
      #5692998 - 02/21/13 03:55 PM

Right but again maybe the 17 is an exception as maybe it is nearly as good as the Pentaxes or TVs? That's what I'm trying to find out...

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Scanning4Comets
Markus
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Darren Drake]
      #5693071 - 02/21/13 04:29 PM

I just went through the same thing....well kinda. I had a 17mm Baader Hyperion before getting a few replacements and finally staying with a 14mm Denkmeier. I *was* going to get a 17mm Vixen LVW, but the 14mm Denkmeier, (which really works out as a 15mm / 70 degree eyepiece in my scope), is better.

The 17mm Hyperion showed a combination of coma, FC and some astigmatism near the edges in my 10" F/4.7 Newtonian. The aberrations would start at around the 70% mark and getting worse as you progress towards the edges. It will probably work a lot better in a long focal length scope....not sure, as I don't own one. The eye relief and comfort of the 17mm Hyperion in excellent IMO, but the edge correction in a fast scope isn't good at all. Images in the central FOV were pretty nice. It was a really good eyepiece on M-42 with my 2" Orion Ultrablock in my 2" extension tube.

The 14mm Denkmeier is way better and has excellent eye relief, it doesn't have eye placement issues,(it only blacks out if you get really really close to the lens, as ALL long ER eyepieces do), it has excellent transmission and barlows to optical nirvana. I had it trained on Jupiter using my 2" GSO ED barlow and the image of Jupiter was incredible. I almost got rid of it a few times because I LOVE to try many different eyepieces and I tried to justify my insanity by almost selling it off to try something new until I did a lot of research and realized that there is NOTHING that I would want to replace it with.

The 17mm Vixen LVW is a step up from the 17mm Hyperion and showed a bit more off axis coma than the 14mm Denk, but was miles better edge-wise than the 17mm Hyperion, and it showed tighter stars all over the view, (and it was coma because I tried re-focusing as one does when it is FC, so it wasn't FC because the tell-tale sign for coma was there), fan-shaped little comet-like stars with the fan pointing all towards the edge of the field stop all around. With FC, one can re-focus to fix it near the edges, while the stars in the central area get the FC back again. I've tried the "in between" focus thing with eyepieces that show strong FC and that doesn't cut it for me. I need to be right "in focus".

The 14mm Denkmeier shows extremely MILD coma, which doesn't take away from the views at all, so I kept that over getting the 17mm Vixen LVW. As far as the Orion Strats are concerned here, they are not even close to being in the same league as and I just mentioned. Off axis in a short FL scope, they are a total mess showing every aberration imaginable with major CA.

Another thing was that the 14mm Denkmeier and the 17mm Vixen LVW show pretty much the same field because the 14mm Denk is a 70 degree eyepiece,(it is listed at 65 degrees, but trust me, this EP is 70 degrees), (and really anywhere between a 14.5mm and a 15mm EP), and the 17mm Vixen LVW is a 65 degree eyepiece, so you'll get a bit more magnification with the same true FOV.

IMO, only the 17mm Vixen LVW can hang with the 20mm Pentax XW. The 17mm Vixen LVW showed a little bit of coma from the mirror and the 20mm XW to my eyes showed a slight bit of FC. The 20mm Pentax XW will have better transmission on DSO's. The 17mm Baader Hyperion edge-wise can't hang with the XW's.

Cheers,


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Starman81
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Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Darren Drake]
      #5693073 - 02/21/13 04:30 PM

Quote:

Has anyone ever done a detailed comparo of the 17 Hyperion to the 17 Delos? Also I wonder if the field curvature issue with a 20XW would sway someone enough to go with a 17 Hyperion (although not quite the same fl)instead of the XW...




Darren, I have a 13 Ethos and a 22 Nagler T4, a couple amazing eyepieces no doubt, but even those are not enough to get me to part with the XW 20 & 14. So I do not expect the Hyperion 17mm to do so in regards to the XW 20. The 20 & 14, though they are affected by FC, still have A LOT going for them that the rest of the 1.25" XW's have as well:

- excellent contrast/transmission
- cool tone with great color rendition
- most comfortable exit pupil ergonomics
- best design of adjustable eyecup
- relatively lightweight and not too big (this is specific to the 20 & 14)

Not to mention, the FC is cleaned up decently enough with a Paracorr, something a large number of fast dob owners already have. For those that don't, focus 1/3 of the way out from the center for a satisfactory view and the younger eyes the better for accomodation.


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Miro
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Reged: 08/13/07

Re: DO BAADER HYERIONS COME CLOSE TO PENTAX XW new [Re: Darren Drake]
      #5693097 - 02/21/13 04:37 PM

Hi Darren,

I've got XW20 and 17mm Hyperion. I used to have the 24mm and 13mm Hyperions. In my f4.6 dob, the 24mm wasn't all that good, mainly because of the edge softness. The 13mm was significantly better but its blurry field stop and softish edge bothered me.

I non-critically compared the 17mm against Nagler T4 17mm. The Nagler didn't have enough usable eye relief for me. When I first looked through the 17mm Hyperion, I remember thinking; How can be this be so good for the price, compared to the Nagler. With the Paracorr the edge of field in the 17mm is very sharp although with quite a bit of AMD I think.

As for XW20 vs 17mm Hyperion, if I couldn't use them with the Paracorr I might choose the Hyperion.
Having said all this, XW20 feels nicer with higher perceived contrast. I've never compared them on threshold targets only mostly on clusters and brighter nebulae.

Miro.


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