［译］一些高端目镜的比较贴

在ASTROMART论坛里看到了一个主题帖子，感觉挺好的，转过来，可能很多同好都看过了，还是和大家一起分享一下把。不过内容比较多，我要先占几个坑留着慢慢翻译，英语水平也一般，大家谅解阿。

Beginning of the Orthos tests

Well, I looked at a few of the Orthos last night and the week before and am beginning to form some opinions on the Clave, Pentax, Zeiss and others that I have been loaned for testing.
The results so far favor the Zeiss. But, not so much for the view as for the eye relief and eye position characteristics and comfort.
The Zeiss and Zeiss Jenna EPs are very sharp and clear as well as good contrast. The field stop is sharp as a tack and of course the field is flat and without curvature.
The Clave has a very good field to and the contrast is on par, but the eye relief and associated black outs is more pronounced, making the difficult to use with glasses and even without them. I found that my eyelashes were in constant contact when seeing the whole FOV.
The Pentax was very good visually, but it was on the verge of bring short on eye relief for glasses and just barely adequate to keep the lashes off the EP.
The Galoc EP was way to tight for my comfort and the wife could not use it at all with glasses and had trouble even without the glasses.
We were using the crater Thebit for comparison as it was next to the terminator and had good contrast and depth as well as some small sharp features.
One of the interesting observations was unexpected however. Both the wife and I found the Pentax XL 10.5 EP showed as much contrast and detail as any of the Orthos, even the Zeiss. Also, it was a little easier to spot some of the very small features and craters with it. There was a quite small light feature on the end of a rill that showed very well in the XL, but did not show as well in the other EPs.

                               
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Not sure what to make of that!

                               
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I did not expect the XL to compete that well with the high end Orthos, but it did and even perhaps excelled slightly. Very unexpected.
I will be doing some others comparisons soon. Last night was using 10mm range EPs only. Seeing was good but not great and there was a little high haze. But, the conditions were the same for all comparisons, so I think they are still valid.

昨天和上一周我看了一些OR的目镜，形成了一些关于 Clave, Pentax, Zeiss以及其他我借来的目镜的一些看法。
结果是ZEISS最好，但是和它的出瞳和舒适度并没有像他的成象那么好。
Zeiss 和 Zeiss Jenna 目镜非常锐利清澈，反差很好。视场很平，像大头针一样尖锐，并且没有场曲。
CLAVE有非常好的视场和反差，与ZEISS打个平手，但是出瞳距离很明显的不舒服，戴眼镜甚至不戴眼睛看都很困难。当我要看全部视场的时候，我的睫毛不断的碰在目镜片上。
PENTAX视觉上非常好，但是也有出瞳距离短的问题，睫毛也容易碰倒镜片（根据词义，比CLAVE稍微好一点）
GALOC（WHAT‘S THIS？）对我来说也不舒服，我妻子戴眼镜根本就没法用，就是摘下眼镜来看也有困难。
我们用了月坑进行了对比，因为月坑有高反差和更多小的细节。
观测中我们发现了一个很有趣的现象，我和妻子都发现PENTAX XL10.5在反差和细节表现上，和其他任何的OR目镜甚至是ZEISS一样好。而且它在区分一些很小的细节和坑洞上，更加容易。XL能够表现更多细小的特征，而其他的目镜在这方面表现得并没有那么好。很不可思议，我并没有期望XL可以和这些高端的OR目镜有一样的效果，但是他确实做到了甚至稍微的超出了一点，非常意想不到。
我将继续做其他的一些对比，昨天晚上只使用了10MM焦段的目镜。视宁度很好但不是最好，有一点薄雾，所有目镜的测试条件都是一样的，所以我认为这个结果是正确的。


Hi Floyd,
Very interesting comparison using the XL and the orthos! One would expect the simpler designs to have better contrast. Did you try any other observing targets to comfirm this observation? BTW, Did you have a UO ortho to throw in the bunch too?
Looking forward to your further observations and comparisons of these eps.
Thanx!
对XL与OR的比较很感兴趣。大家都认为简单结构目镜可以获得更好的反差。你有没有试验其他的观测目标来验证你的结果？你有UO OR参加这次的比较么？期待你更进一步的比较。


I see this all the time in comparisons made by experienced observers. I think when it comes to well coated and well made eyepieces, factors like local conditions, as well as an observer's comfort and inviduality wrt to one's own biology and physical differences, are a more important factor in contrast than the number of elements in the eyepiece. Rick
我认为目镜的做工和镀膜，当地的观测条件，观测者的舒适程度以及生理条件的不同，再对比评测中，这些因素要比镜片数量是多少重要得多。

Rick,
I would have to agree with that assessment. I find that the coatings make a big difference when multiple surfaces are in play. The Pentax also has a slightly different color that seems to make it easier to see detail.
同意。我发现多层镀膜在表现上非常的不同。PENTAX也有轻微的颜色，以至于再看细节上更加容易一些。

Hi Dave,
We did use a few double stars and an open and globular cluster for comparison, but mostly we used one crater so that it would be very easy to spot differences.
I do not have any UO Orthos at this time, so they were not included. I have compared them with the Pentax XL, TMB/BO, Nagler and Radian series though. The Pentax won in that test as well on Jupiter.
The Pentax XL seems to have some extraodinary coatings that tend to give very good detail due to contrast I think.
我们也用一些分解双星和球状星团来进行测试，但是大多数条件下我们都用月坑，因为月坑可以非常容易的看出不同来。我没有UO OR，所以这次测试没有他。我们比较了Pentax XL, TMB/BO, Nagler ，在木星的测试上，还是PENTAX得略胜一筹。我认为PENTAX XL看起来用了一些特殊的镀膜技术，所以可以表现出更好的反差和细节。


我爱祖祖注：XL好像已经停产了，应该属于广角长出瞳的多片结构，但是视场不超过70度，现在他的替代品是XW，印象是这样的。

[ 本帖最后由 我爱祖祖 于 2007-5-24 14:27 编辑 ]

Floyd, FWIW, I came up with the same findings when I was comparing a bunch of orthos (Pentax, AP, UO, etc.) and found that my Pentax XL's and now XW's showed me as much or more detail than the orthos. That is why I don't own anymore orthos and have all of the Pentax XW's from 10mm on down to 3.5mm. Bob
在对一些OR目镜的比较中，包括PENTAX、AP、UO等等，我也发现XL和现在的XW比OR能够表现更多的细节。这也是为什么我没有一个OR目镜，我现在有所有XW10毫米以下的目镜（10、7、5、3.5 ）

Hi Bob,
Kind of interesting huh? Seems that there is more to EPs than simple design vs. complex!

                               
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I am sure that coatings must be the answer, but certainly the better Orthos have excellent coatings too, so I am somewhat stumped for a complete explanation.

                               
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我确信这个结果肯定是因为镀膜的原因，但是一些更好的OR目镜也有优良的镀膜，我想知道更全面地解释。

Floyd,
Perhaps the visual acuity/exit pupil of the observer enters into the equation. At Pinos, one TAK owner told me he sold his naglers and radians and now uses pentax XW eyepieces exclusively. Perhaps the viual range of the spectrum that is optimum for one observer differs from that of another so the results will seem different with various high end eyepieces although they may all be of very high quality.
Just a thought on the variations we read about...
可能和观测者的视觉敏感度和瞳距因素也有关。一个有高桥的同好告诉我他把他所有的NAGLER和RA都卖了，现在只用PENTAX XW目镜。可能每个观测者对可见光的敏感范围都不同，所以导致了对这些高端目镜看起来有所差别，尽管这些目镜都有很高的光学素质。


Hi Rod,
Another real possibility, not sure what the complete answer might be.
Pentax is certainly a great maker of EPs. I think their coatings are some of the best. Certain ones of the different series has its short comings (field curvature for instance), but this is true with most EPs I think.
PENTAX是很著名的目镜厂家，他的镀膜也是最好的之一。但是有些系列中也有短处（比如场曲）。

I am having real trouble accepting these results as is: however I would not question in the slightest the individuals, perceived observations and that they are striving for objectivity. However, I would like to know more- that is what aperture through which these initial results were compiled? Is it possible that in telescopes ie larger Newtonians that illuminate the light cone to such a degree that the simpler orthos do not offer as great an advantage as they would with smaller aperture (3-6inches)systems usually associated with refractors, where light through put is more critical. Can this possibly be true of all manner of telescopic systems and sizes where modern widefield designs are now the equal of 3-4 element eyepieces?
May I just mention that eye glass wearers never seem to be fans of orthos or short eye relief plossls. I seem to remember Terrance Dickinson and Alan Dyer expressing the same ideas that specialized planetary eyepieces were not necessary or particularly recommended. It is just pattern I thought born out of natural perspective.
Perhaps my notion here is too simplistic for more experienced ocular connoisseurs, but this is certainly a very interesting debate and I am staying tuned here for more opinions.
让我接受这样的结果有些困难。我一点也不质疑有一定个人主观因素，尽管已经尽量争取做到客观。然而我想知道，测试中用了多大口径的望远镜做出了这个结论？有没有这种可能，例如是使用了更大口径的牛反，因为可以提供更高的通光量，反而让OR这种简单的目镜的优势不像在3-6寸折射镜中发挥得那么明显呢？很有可能是因为这个原因，所以使得这种现代广角结构的目镜可以达到3-4片简单结构目镜的效果？我可能说过，OR以及短焦的PL并不追求镜片镀膜的质量，我记得Terrance Dickinson 和Alan Dyer 说过一样的意思，对专门的行星目镜来说，镀膜质量不是必需的，镀膜只是一些噱头而以，根本没有必要。
可能我的观点对一些观测行家来说太极端，但是这是一个很感兴趣的话题。


Hi Jerry,
This last set of comparisons were done with the 127ED refractor. Earlier tests were performed with a 14.5" Starmaster Dob. I did the last ones for a little change and to see how Orthos performed in smaller apertures and refractors.
最近的测试是用了127ED折射。早一些的测试使用了14.5寸的DOB。我也想用更小的折射看看OR的表现到底如何。

[ 本帖最后由 我爱祖祖 于 2007-5-24 09:51 编辑 ]

Bob, I can't afford a series of XL's and XW's, and they would be too heavy for my binoviewer anyway. The point is that the classic Ortho design has been bettered in numerous ways even by value conscious designs like the Star Splitter and TMB, and costly designs like the XL's. The Star Splitters have very good color performance, and that's important for planetary type observing. Also, too many multi-coatings incorrectly applied tend to hurt planetary performance more than help it. Star Splitters are partially multi-coated for that reason. Some planetary observers prefer highly polished simple designs with no coatings whatsoever, such as old Zeiss Orthoskops. Myself, I prefer limited coatings only as needed, rather than completely multi-coated as a sales gimmick. Good multi-coated designs will of necessity be expensive because each coating MUST be critically controlled in order to not have some deleterious effect in the final analysis.
我觉得XL和XW太贵了，并且对我的双目来说太重了。OR的设计在很多地方很好，甚至可以与STAR SPLITTER和TMB以及XL这种昂贵设计的媲美。STAR SPLITTER 有很好的颜色表现，这个对行星观测很重要。太多的镀膜不仅对行星观测没有帮助，相反还影响了观测效果，正是这个原因，STAR采用的 是部分的多层镀膜。一些行星观测者更加推崇简单设计的、无镀膜的目镜，例如老式的ZEISS ORSKOP目镜。对我自己来说，我喜欢只要满足需要的镀膜就足够了，而不是仅仅作为营销策略的全部多层镀膜。好的多层镀膜设计必然非常的昂贵，因为每层镀膜必须严格控制，以免在最终使用中出现一些反面的效果。


I had a sneaking suspicion that might be the case!
I am very interested in your results.
I have a full set of University Orthos (Volcano Tops; 4mm, 5mm, 6mm, 7mm, 9mm, 12.5mm, 18mm, 25mm), a near full set of Takahahsi MC Orthos (missing only the 5mm; I have the 7mm, rare 12.5mm, 18mm and 25mm), an starter set of Zeiss Jena Orthos (10mm and 16mm), and a full set of the vintage Meade Reserach Grade Orthos (4mm, 7mm, 10.5mm, 16.8mm and 28mm), and would love to do a battle royale.
对这个结果我有一些怀疑，对您的结果非常感兴趣。我有全套的 UO HD OR，几乎全部的高桥 MC OR，10和16 毫米的Zeiss Jena OR目镜，以及一些早期的米德OR，并且喜欢拿他们做些对比。

Your comment about the Pentax is interesting. Last winter I had my sister up to visit. She lives in Los Angeles and is a budding astronomer. She uses a Celestron 8" SCT and a Televue Pronto (the latter a hand-me-down from me). She had never looked through a larger scope than 8" or any scope from anything but a terribly light polluted location.
My location isn't great (NELM at zenith of about 4.5, but it is light years better than hers). We used a 12" Orion Dobsonian and a set of wide field eyepieces including Naglers, Radians, Panoptics, Meade UWAs, Pentax XLs and Vixen LVWs. We observed many winter showcase DSOs and some less well traveled DSOs, and then finished with Jupiter near zenith.
你对PENTAX的评论我很感兴趣。去年冬天，我和我姐姐一起去观测。她用的是C8。他没有用过超过8寸的镜子。我的观测地不是很好，我用12寸的ORION DOB和一套广角目镜，包括NAGLER，RA，PO MEADE 超广角，XW以及LVW。我观测了一些冬季的深空天体以及天顶的木星。

I didn't bring out any "planetary" eyepieces, so on a lark I put in the 7mm Nagler Type 6 since it was the highest power I had on hand. I had low expectations given all of those light leeching pieces of glass sandwiched together.

Boy were we ever stunned. To this day it was absolutely the best view of Jupiter I has ever seen in 35 years of observing. It was photographic. 10-11 distinct belts were clearly visible with lots of inter-belt detail such as ripples, ovals, and the like. Each of the Gallilean satellites resolved as a disc and each had unique coloration. A true jaw dropper - through a "DSO" eyepiece no less.

Perhaps modern glass types, quality manufacturing and bleeding edge coatings are just better period.

Jim
我没有拿出行星目镜，我只用了手头上的N7 T6上到了最高倍。我对这种玻璃三明治的并没有抱太高的期望。吃惊的是，那一天绝对是35年来观测木星最好的，10-11条的云带清晰可见，很多云带的细节包括纹理以及斑点。每个伽利略卫星都能看出小盘面，还有各自独特的颜色。深空目镜也让你大跌眼镜（我自己瞎邹的）。可能现代结构的目镜的做工、质量以及镀膜已经发展到了鼎盛时期。

[ 本帖最后由 我爱祖祖 于 2007-5-24 10:27 编辑 ]

我上次翻译了天空与望远镜里的文章没有人搭理

Hi Jim,
Yeah, I am not completely convinced that the simpler EPs are superior either. There may be situations where they have an edge, but so far I have not seen evidence supporting this.
I have had two full sets of UO Ortho Volcano Tops and several UO HD Orthos as well as a few other brands and I have ended up selling all of them after a few sets of tests and comparisons. They are good, but there are others that I like better.
My main problem with Orthos is the eye relief, especially in the shorter f/l EPs.
There are many good EPs and everyone has their favorites I guess.
Your experience mirrors some that I have had with nights and EPs that you would not have thought would give the best performance.
我还是不能完全相信简单结构的目镜就好。他们可能边缘好，但是到现在也没有证据支持这个观点。我有两套UO的普通OR以及部分HD OR，还有一些其他品牌的。看了一些评论和比较后，我就不卖了。他们都很好，但是还有其他我更喜欢的。我最主要的问题就是不喜欢OR的短出瞳。还有很多其他的优秀目镜，每个人都有自己喜欢的。你的经验说明，一些意想不到的天气以及你还没有考虑到的目镜，可能会给你更加好的表现和意想不到的收获。

Maybe you had a short period of extremely good seeing. Rarely do I get seeing conditions where I can even exploit the full capability of my Russian 6" Mak on planetary observations.
你还遇到过这样极其好的天气，我几乎没有碰到过这样的天气可以把我的6寸俄罗斯马卡的行星观测潜力全部发挥出来。

[ 本帖最后由 我爱祖祖 于 2007-5-24 10:49 编辑 ]

Hi,
This has prompted me to try a Pentax
10.5 XL again. I may put together
another set of them for my 10" F5 dob
& C-14. I love the comfort of long ER
eyepieces these day's and want the quality as well.
又激起了我买XL10.5的冲动。我可能还会买XL其他型号的，配我的10寸DOB和C14。我还是喜欢长出瞳的目镜，并希望有更好的质量。

Hi Bill
I do remember!

                               
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I have to admit, it is true and the 10.5mm XL is still one of my favorite EPs for many uses.
Yeah, the UO Orthos are a good price and a good EP, but they do not excel in anything really. The Zeiss is much better as is the Clave and Pentax as far as image goes.
我必须承认，XL10.5是我也是很多人喜欢的目镜之一。UO OR也是一个好的目镜并且价格便宜，但是确实他并不是在所有的方面都表现得那么突出，ZEISS CLAVE PENTAX像质要更加好。



John, Good points. I can tell you that I have tried and owned just about every eyepiece out there at one time or another (except for the rare ones). Sadly, I couldn't keep the scores of ep's all at one time. My conclusions about Pentax's came from use with high-end refractors as well as reflectors. Tonight for example, I am looking at the Moon and when I first started looking at about 7 p.m. Eastern Time, the view of Luna through my 10mm Pentax XW in my 12.5" f/5 Zambuto-mirrored Portaball took my breath away. Tonight at various times, the surface detail has been some of the best that I have ever, ever seen. Last night and this morning, that was definetly not the case. But tonight, at some brief periods, there have been views where there is no shimmering from the atmosphere, etc. When the atmosphere became slightly turbulent, I backed down to my Meade 14mm UWA which I love and the surface detail was not as distinct as with the Pentax XW taking into account the mag differences and eventually the atmospherics. In regard to Jerry Wright's skepticism, I used to own a scope he now has (8" f/7 Spooner mirror) that also allowed me to do some incredible testing and lunar/planetary observation when I lived in South Carolina. Even in SC, the Pentax XL's were generally the winners back then. I had tried most of the Naglers and many of them in different model iterations and I found that the higher power Pentax ep's (10mm and below) gave my eyes the best views most consistently. Bob
很好的主意。我可以告诉你，我也曾经时常想拥有各种目镜。但是我还是跟不上发展步伐。我发现PENTAX 不仅适合高端的折射，也适合反射。比如今晚，我从7点开始观测月球，用我12寸的镜子和XW10，表面细节是我见过最好的。昨天晚上和今天早上就没有那么好。今天晚上的大部分时间里，观测条件都很好，后来大气开始出现轻微扰动，我换上我很喜欢的MEADE UWA14，考虑到倍率的不同和大气的因素，UWA在表面细节并没有XW那么明显。以前我住在加利福尼亚南部时，经常用8寸的反射对行星进行测试，反复用各种手段试验过大部分的NAGLER，还是XL稍微好一些，并且PENTAX的高倍目镜（10MM和以下的）始终的给你最好的观测效果。

[ 本帖最后由 我爱祖祖 于 2007-5-24 11:15 编辑 ]

Hi John,
I have had the pleasure to test many different makes and models of EPs. Televue, Pentax, Nikon, Tak, UO, Zeiss, Clave, Meade Celestron, Parks, TMB, AP, Siebert, Rini and many more. I have tested them in Refractors, SCTs, Newtonians and on many different objects and types of objects.
I have no interest in any manufacturer or company.
I have an open mind and am always willing to try something new or different. I have no real preferences, but I do have my own favorites for my type of viewing and those comprise my collection. I must admit that I have mostly Televue, but I also have TMB/BO, Meade and Pentax as well. I have sold so many different types and names of EPs that I loose track.

                               
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But in the end the ones that I have now have stood the test of time and scopes so they remain as others have left.
我喜欢测试各种不同结构的目镜， Televue, Pentax, Nikon, Tak, UO, Zeiss, Clave, Meade Celestron, Parks, TMB, AP, Siebert, Rini 以及其他的，我在折射、折反射、牛反上通过不同目标和形式的目标测试他们。我并不倾向于任何一家制造商或者公司。
我喜欢尝试各种新的各种不同的、新式的目镜，没有特别倾向的。我是根据我的喜好搜集目镜的。我有大部分的TV，但是我也有TMB／BO，MEADE和PENTAX的。把我不喜欢的各种类型和名字的都卖了。最后剩下的，都是在测试中获得好评的目镜。


Floyd and Bob
I am somewhat skeptical I admit but open minded enough to realize that if this is in fact the case I can sell off a large collection of ortho eyepieces and be just as happy for it. I have a full set of Pentax XW's, so I am covered and have no real equipment bias. I trust these findings and Floyd has disproved my aperture theory but I say lets keep testing just to make it more statistically valid. I am also presently in a position to run side by side tests as well so I guess I have a new project.
Just for the sake of discussion one night I spent one hour setting up a TMB 152 on a MI-250 Gemini and went inside to await darkness. When I returned the sky was overcast and cloudy. It was either just dismantle the whole rig or point it at Jupiter just to see what I could see. Jupiter still revealed to me enough detail through the worsening transperency that I spent about 35 mins with it. During this time I switched back and forth between a 5mm Nagler T6 and a 5mm Pentax XO. The little 45 degree XO was perhaps 25 percent brighter under these awful conditions! I could still register a fair amount of detail.
Having said that I myself have been very impressed with the T6's on their own, I just always felt that at high powers the orthos for me held the lunar/ planetary image together better over 200x no matter what the seeing conditions . Now I must at least consider that this is a false assumption.
我也有点怀疑这个结果，如果是真的我就非常乐意卖掉我手里一大推OR目镜。我有一套Xw，我对器材没有偏见。我相信这个结论，并且FLOYD反驳了我的口径理论，但是我期望能够继续测试，使得结论更加准确。
一天晚上，我用TMB152看双子座的MI250，开始一直呆在屋里等着天黑。当我出来的时候，天空开始有云。我把镜子指向木星想看看能看到什么。尽管天气比较恶劣透明度不好，木星仍然能看到很多细节。我花了35分钟反复比较N5和XO5。视场只有45度的XO，在这种恶劣的天气下，亮度要比NAGLER高25％左右。我还能记得当时那些丰富的细节。
对N5 T6自己声称的性能我还印象非常深刻，但是我还是感觉无论在何种天气下，在超过200倍还是OR在看月亮和行星的表现更加好。

[ 本帖最后由 我爱祖祖 于 2007-5-24 11:51 编辑 ]

Jerry, Suggest you try a lineup of the Nagler, Ortho, and XW with that killer 8" f/7 you own. Collimate it really well and then take a look at the Moon tonight if that is possible. I think you will be amazed at how something like a 10mm or 7mm XW will compare very favorably to anything you have. I personally found that the light throughput on the Naglers did not agree with my eyes (they always felt like I was looking through coke bottle bottoms?). Probably the best ortho I ever used was a Pentax SMC 7mm. However, when I compared it to the Pentax XL's at the time, I did not see enough of a difference to warrant the tight eye relief and small FOV. Bob 建议你用8寸的镜子试验一下NAGLER OR和Xw。有可能的话就看一下月面。我觉得一定会吃惊于XW 10或者7的表现，我发现NAGLER不适合我，就像从茶色玻璃里面看一样；可能最好的OR就是PENTAX的SMC 7。我比较过SMC7和XL，但是我没有看出太大的区别来。


Bob
Will do. I should be able to have a Pentax shoot-out weather permitting. Most of my Naglers have emigrated back to the USA. There were just too many to collect and I had some dependency issues.


Jerry,

I would not give up your Orthos quite yet

                               
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Each time a review is done by an individual, you simply have to consider it a single data point for you to add to a 損ersonal?collective. Floyd does excellent reviews and has the wonderful talent of cutting to the chase straight away (i.e., lean, mean and efficient reviews - smile). However, as with all reviews, one data point does not make a definitive case, especially not for your unique observing situation.

Besides the obvious parts of the observing chain we all readily consider ?telescope and sky conditions, the atmosphere and our own physiology affect things dramatically. That being the case, Orthos may indeed work best for you! As examples, consider how there is still argument on stellar colors, especially in doubles. Some people see orange, others red, others violet. Who抯 correct? Why the differences? And the same goes for Mars! People have been reporting differing colors on Mars and even shadings and shapes over the course of the same evenings. How is that possible?

I抎 like to suggest that it抯 3 basic things causing the differences: atmosphere, physiology, and perception. For colors, and hence shadings that will become visible for planetary atmospheres, local refractive qualities of the atmosphere will affect this. So how your local atmosphere (pollutants, gasses, local pollens and particulates) refracts and affects light makes things different from place A to place B. Physiology comes to play in many many ways. One example is seeing color changes in real time. This happens when your telescope-sky-eye combination reaches the threshold of where your eye flips between seeing something in color vs grayscale. So if the object, or small portions of it are at that threshold, then things get strange in what you observe. So one reviewer may have been at a different place along that threshold than you, thereby yielding different results. There are a host of things related to physiology that we never keep track of because it抯 just too many variables such as: Bezold-Brucke phenomenon, Tritanomalous vision, Purkinje effect, simultaneous contrast, After-images, etc. All these things 揷hange?what we see, and therefore lead to differing results when we review eyepieces. Finally we have 損erception?or how our expectations affect what we see. As the old research adage goes, 揑f I hadn抰 believed it, I would have never seen it.? We all have personal expectations which affect our perceptions. This is perhaps why the final best determination of what eyepiece will work best is just to try them. For things like astigmatism and chromatic aberration and spherical aberrations, etc, they are cut and dry to determine for the most part. But when we get to which EP is sharper or produces a 揵etter?image, then we are in a huge multivariate land where all those physiological and perceptive and atmospheric things come into play and there really is no absolute 揵est?but only 揵est?for the unique person-telescope-local observing site combination匢MHO of course J
主要是说明观测受到天气、镜子以及生理机能等方面的影响。
So don抰 ditch those Orthos! If for no other reason than this卼he basic reason for the Ortho is that it gives a nice flat 揳ccurate?field of view. It all started with microscopes and medical researchers need the images to be accurate so determine the biological structures and problems they are trying to diagnose or discover. So while many of the wide-field EPs do produce wonderful and pretty imagry, remember that if there is any barrel/pincushion distortion or the similar, then what you are observing is not how it really looks! So if your interest is in seeing a star field as it actually is, then Orthos are a sure choice. So if for no other reason, Orthos rule in that respect as a general rule.
这段主要是支持OR的观点。广角目镜尽管可以产生很漂亮的画面，但是普遍都有变形，从这点考虑，所视并非所见。所以如果你要看到星体的真正还原，OR是当人不让的选择。

[ 本帖最后由 我爱祖祖 于 2007-5-24 12:20 编辑 ]

Hi Bill,
Good points!

                               
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I could not agree more that a review is but one point of view. I do like to have at least two pairs of eyes working when I do one though. If we see the same thing, then I feel that it is more likely correct, but if we wee things differently, there might be personal bias involved.
要想让实验更准确，最好多让几个人来测试。如果测试结果是一样的，那么结论就是正确的，否则就可能会是有个人主观因素的存在。
The atmosphere does indeed make things appear differently at different times and can even happen so quickly that changing EPs can be enough time for the view to change. This is why I will always repeat the test again if I see something in one EP that I did not see in the other, I will go back a forth until I am sure that it is repeatable.

I will say that it is true the Zeiss, Pentax, Clave and other Orthos produce a marvelous flat field! But at 40?or so, if you use that portion of a wider FOV EP for the test, then many times there is no difference. I believe that this is a proper way of looking at this issue, because if you are comparing EPs with a significantly different FOV, the you must try to equal out the field by using the same area. This is only true when using EPs with 50% or so difference and when you are not trying to evaluate the EP for all attributes seen at the outer edge.

This is what I try to do when doing planetary EPs, I try to use the On-axis for the most part and then also look at the edge performance. But, I mainly look at on-axis so that the larger FOV does not come into the picture, because our eyes tend to like the wide fields. However I always include the edge performance information in the review as additional data.

I would also say that different eyes, scopes and lighting conditions could effectively change the outcome of a test. This is why it is so important that as many people as possible do similar testing in different areas with different scopes. Then you begin to get a complete picture.



There are new EP designs that retain the "true view" of the orthoscopic design while improving on eye relief, AFOV and other factors. The Ortho uses crown glass instead of flint glass in its external lens elements, and that makes it much more rugged in hazardous emviroments like student use. I am surprised that 1000 posts could be posted regarding Orthos and nobody but me seems to key in on that basic fact. Orthos are hard to tear up in the hands of the ignorant and unconcerned, so you can buy off the used market with little fear. The Ortho has been matched or bettered in all its optical quality of view characteristics by other newer designs. The price may be higher in those designs, but not necessarily by any appreciable amount if you are serious about a good EP.


Hi Jerry,
The 10.5mm XL was only 108x in the 127ED, but that was all that any of the EPs produced so it was a fair situation.
On brightness, the Orthos may have had an edge, but I did not really wee any. The Moon is pretty bright though.

                               
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I think that you should do a side by side with the XW vs. Ortho and see how it comes out for you. I for one would be interested in your opinion. Especially if you duplicated the test with a single crater on the Moon and just switch EPs and see what features and details stand out better.
I have done several tests in the last 3-4 years using Orthos vs. various EPs and honestly the Orthos never really won, they did tie a couple though.
But, I still think it is possible that on certain types of objects that the Ortho might prevail. I will try some more double stars next time, if the conditions will allow it.
XL10.5在127ED上是108倍，对其他的目镜测试也是公平的。
在亮度方面，OR可能会略胜一筹，但是我真的没有看出区别，月亮都是一样的明亮。
我认为你应该同时测试一下XW和OR，看看到底结果如何。当你重复测试一个月坑，并且只是更换目镜，看看到底哪一个细节和特征更明显。
过去的3－4年里面我做了一些OR和其他目镜的测试，但是OR并没有明显的优势。但是我仍然相信对某些特定方式的测试，OR可能会略胜。下一步我还将测试一些双星。

[ 本帖最后由 我爱祖祖 于 2007-5-24 12:33 编辑 ]

Man, you guys need to just observe more and not worry so much about miniscule differences between eyepieces!

                               
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Last night I had my new-to-me FS128 out looking at the moon. Luna looked amazing in my 7mm Pentax XW, at 146x and with 29 arc minute tfov. You know, I never once found myself wishing that I had 8 other 7mm eps to compare against the XW!

                               
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All of this is, of course, just good natured ribbing. I appreciate those of you that do have multiple eps in the same focal length and are willing to spend the time doing these comparos. Makes for very interesting reading!

Doug
Midway, FL


Sorry for the skepticism, but if you want to convince me
to pony-up for a Pentax XO, you'll have to do better!

                               
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Jupiter not naked eye -- that means at least 5 mag extinction or
more than factor 100 absorption from clouds. Trying to
judge one eyepiece 25% brighter than another with factor
100 absorption clouds blowing around -- sounds difficult
at best. I appreciate the efforts and dedication, but
I'm going to wait until you get some better weather.

What would I do? I took one look outside and decided it was
too cold / windy for my butt. I cleaned eyepieces instead....

                               
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John
I've looked through my 5mm Pentax XO about 100 times since. I have not found any better!It is not 25% brighter but under non-viewing conditions that is what it seemed like. I just remember being surprised as my initial reaction and then went back and forth to confirm. I do admit to having a past with (numerous)5mm eyepieces so I am carrying some baggage.
But alas a new Pentax 5mm XW is calling it outside so I think there is going to be some serious fireworks on the horizon. The moon is low so we are going to throw in more turbulence as well. It's getting dark so don't change your channel.
Jerry

Yeah Bill, I agree, the color factor can cause one to see the image as brighter. If an EP is on the cool side (more white and blue) to the eye it seems brighter than if it is on the warm side (yellows or red tones) yet you can see the same stars in each. I find the cool side to appear a bit more washed out, yet the details are there, just harder to see than a neutral or warm EP.
Coating make a big difference in the relative view. Thing just look different with the various coating color preference.

[ 本帖最后由 我爱祖祖 于 2007-5-23 23:43 编辑 ]

I have to make a long story short. I did all manner of obscure lunar observing tonight with a host of various Pentax eyepieces through a TMB 6"/F8. Seeing conditions I would rate as average and getting better as the night progressed.
7mm: 0-7 vs. 7XW . I could not declare a winner . I believe the view in the 0-7 somehow seemed more natural on mountain ranges and lunar topographical features. I felt I saw more crateriets at the threshold of detectability with the XW. I cannot explain this disparity. A virtual dead heat but the XW has the 'Wow' factor.
5mm: 0-5 vs. 5XO vs. 5XW We have declared a winner! The 5XO did shine relative to its competition. This was a narrow margain of victory but it does reveal finer detail at higher powers. I would rate the 0-5 over so slighly ahead of the XW only if I had to pick a winner. They were both excellent.
10mm: 0-9 vs.10 XW Could not really hazard a guess really as image scale and conditions did not allow. Essentially I found the 10 XW an excellent eyepiece and then brought out the 11 Nagler T1 circleN. I thought the old warhorse held up very well in direct comparison ( I had to change my diagonal holders because Floyd has my 2" diagonal adapters wrapped around his XL's)and it was not editing out fine detail.
All in all I think it was a victory for modern eyepiece designs.Light put was not appreciably different to my eye on this night. With all that extra FOV,ER,and creature comfort there is not in my opinion a major difference at least on this target(where is Jupiter)between XW's and the SMC orthos. My modern 5mm XO showed me that I was right about that one. It's a keeper! All is well!

长话短说。今天晚上用TMB6寸的镜子测试了一些PENTAX的目镜，天气状况良好。
O 7 和 XW7 ：分不出胜负。OR7看到了更多的山脉和地形特征，XW则看到了更多的月坑。虽然不分胜负，但是XW表现很好不得不叫绝。
O 5 、 XO5、XW5：XO5最好，虽然只是略胜，但是在高倍下XO的细节最多。如果非要在O5和XW5中进行比较的话，则O5略胜于XW5，但是只是很小很小的一点胜出。他们都非常优秀。
O 9 和 XW 10：基本表现差不多。
我认为，现代结构的目镜是胜利者。通光很好，并且有大视场、长出瞳的优点。在对木星的观测中，XW于SMC OR几乎没有区别。我的现代结构的XO5还是最好的，我的选择是正确的。总之，每一个都很好！


Hi Jerry,
Thanks for your input into the fray!

                               
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I agree with you, the differences if there are very small. I also agree with you on the small craterlets vs. mountain ranges, this is what I found too, the smaller features seems easier to see.
It is amazing really, that the newer multi-element EPs hold their own or surpass the more simple EPs that were once considered the ultimate for detail and contrast.
I am happy to say that the 1.25" to 2" adapters are very happy with their new XL partners in the case!

                               
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I still have one extra that is awaiting its mate.

                               
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[ 本帖最后由 我爱祖祖 于 2007-5-24 13:25 编辑 ]

Pardon my jumping in for Floyd, but I believe the eyepeices he's using are the Zeiss Abbe Orthos (31.7mm) which were considered a limited production run, or Carl Zeiss Jena (24.5mm) which are commonly reffered to as CZJ. The 12.5mm Floyd refers to earlier is a CZJ 12,5-O i.e. a Carl Zeiss Jena 12.5mm Ortho. To my knowledge, none are microscope eyepieces.
Clear Skies, Bill

[ 本帖最后由 我爱祖祖 于 2007-5-23 23:47 编辑 ]

祖祖好水！

呵呵，不是阿，真的很长阿，如果不全部弄过来，大家看了一部分也不明白阿

好像我抢了你的坑…………

就说呢……我一个字都不认得！

哈哈哈哈！

原帖由 Shmilyprince 于 2007-5-23 22:48 发表

                               
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好像我抢了你的坑…………

上面的坑稍微紧张了一点，不过够用了