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标题: 翻译： C80ED 和 Orion 80ED 的比较 [打印本页]

作者: 文强 时间: 2007-5-10 09:02
标题: 翻译： C80ED 和 Orion 80ED 的比较
原文出处 http://www.cloudynights.com/item.php?item_id=1192

I started my amateur astronomy "career" and love of telescopes in the 5th grade. My teacher, Mrs. Cameron had an interest in astronomy, so it was only natural that she spent more time on the subject than most teachers. That was a mere 56 years ago, although it seems just like yesterday. Since then, I've built or owned a whole variety of telescopes, and my first scope was a 3" reflector from Harry Ross Company. No one's ever heard of the company, but I remember the telescope well. Now I find myself, years later, still enjoying this hobby that we all share. I own 6 telescopes, including a C8, C9.25, C11 and Takahashi FS-128. The Orion ED80 has received a good number of well deserved reviews from a variety of sources. These were good enough to prompt me to buy one of these scopes, and I've found it lives up to its reputation for relatively color free images. I had some fun one evening when a friend of mine who owns a TeleVue 85 and I had a shootout of the Orion scope and his. He was pretty angry with himself in that he spent much more money than needed for a good 80mm aperature telescope. I became curious about the Celestron C80ED after I saw a description of the scope on the Celestron website. This was just before Celestron was sold to Synta, the company that manufacturers the ED80, the C80ED and more. I also realized that the lens for the Orion ED80 and C80ED would be the same, so obviously both scopes were perform about the same. Without much thought, I ordered one of the Celestron C80ED's from telescopes.com and received it four days later. As I opened the shipping carton, I found that the scopes was inside an inner container as well. The scopes was well packed and the finder, a 25mm Plossl eyepiece and 45-degree diagonal were all in their own separate little boxes in front of the objective. A note about the 45-degree diagonal. For some reason, probably so as to compete in a slightly different market than Orion, Celestron sells this telescopes as a "spotting scope". At first I wondered why I couldn't find the C80ED on many of the vendors' websites I usually visit. I found it by chance when looking at the spotting scope section. Upon first inspection, I found the scope very well made. I really didn't know what to expect, as I had never seen one of these before. The scope is all metal, and differs from the Orion in a couple of ways. First, the OTA is 90mm in diameter as opposed to the 100mm diameter of the Orion ED80. One interesting aspect of the telescope is the "tube ring". It fits very tightly and when I removed the ring, it left some dull areas in the paint. The tube ring is unique in a couple of ways. It uses "latches" to close the ring around the OTA -- the kind of latches you normally see on a foot-lock trunk. There is also a "built-in" dovetail that is part of the casting which is CG5 compatible. I found that a nice feature, as I was using a Stellarvue M1 alt-azmuth mount to hold the scope. There is a also a 1/4-20 hole is one is inclined to put the scope on a photo tripod. The focuser is a rack and pinion whereas the Orion has a crayford focuser. The action on the focuser is "OK" and tended to stick slightly. After a bit of cleaning and running the extension tube in and out a couple of times, it was more acceptable. Still, I like the crayford focuser much better. The C80ED supports 1.25" and 2" eyepieces and a 1.25" eyepiece adapter is included. The only plastic on the scope is the dust cover for the objective, and while it serves its purpose, it doesn't fit very well, and has a tendency to fall off readily. The shape of the dew shield is curved a bit, so it is unlikely that there will be a nice aftermarket dust cover very soon. Finally, the C80ED is an attractive shiney black color and looks stylish, if a telescope can be described as such. The finder is a 6x30 straight-thru instrument with cross hairs. The finder bracket is nicely done with a spring-loaded adjuster and 2 screws. This way, adjusting the finder is quite easy. The dovetail that holds the finder also accomodates the kind of red-dot finder that is sold just about everywhere, including the Orion EZ Finder. I actually prefer the red-dot finder for this scope. The 25mm Plossl eyepiece and 45-degree diagonal are useable, but I've put them aside for higher quality accessories. One of the first things I did was check the collimation of the scope. I used a cheshire and found the collimation appeared to be "right on". It was perfectly collimated. The Orion, on-the-otherhand, required an adjustment of the focuser assembly to bring it into perfect collimation. The only thing remaining was to get the scope out under the stars for first-light. I chose to use a Williams Optics standard 90-degree diagonal and a TeleVue 17mm Nagler on the scopes' maiden voyage. As I waited for the sun to set I noticed that Venus and Jupiter were clearly visible. Venus was a bit low on the horizon for any meaningful views, but Jupiter was high enough. As I brought the scope into focus I was absolutely thrilled with the performance. The image was just beautiful. Jupiter was in sharp focus around its entire limb, there was considerable detail on the planet and not a hint of false color. I increased power to a 12mm Nagler and then a Meade 8.8mm UWA for some really nice higher power views. It was finally dark enough to perform a star test. I'm the kind of guy who routinely checks the collimation of his telescopes, particularly the SCTs. I used the 8.8mm UWA for this purpose and chose Polaris as the star. At 2nd magnitude, it an ideal object for startests. The defraction rings were perfectly formed both inside and outside of focus. The star test confirmed that the collimation was right on. Since, the lens cell and focuser affix to the OTA with threads, there is no means by which collimation can be corrected if needed. Fortunately, this wasn't a problem. When in focus, the stars are beautiful pinpoints against a nicely contrasted background. The scope "snaps" into focus as one would expect. I'm sure someone who knows more than I would find some issues with the figure of the lens, but since it can't be corrected I only care about the performance of the scope "in focus". To finish out the evening, I chose to look at the common Messier objects we all love at this time of year. The globular clusters such as M13 and M22 were just spectacular. The dumbell, the ring and Lagoon nebulas were really nice viewing. The double cluster was outstanding. I did power up to a 12mm Nagler and found that this is the eyepiece I prefer for deep sky observing with this telescope. Since the telescope is an f7.2 with a 600mm focal length, I found it very easy to locate objects with the red-dot finder. I had a chance to compare the C80ED with an Orion 80ED the other night. My friend and I used the same eyepieces and looked at the same objects. The scopes, as one would expect, are equivalent. I did notice my friends ED80 was packed into a smaller space, as he removed the dew shield and found a 4" plastic cover for the objective. The dew shield of the C80ED doesn't come off quite easy enough so as to accomplish the same space-saving storage. All in all, the scope is a real winner. The 90mm OTA looks less "stubby" than the ED80, and the all black color scheme is very nice. It would have been nice had the focuser been the crayford style and the dust cap was of higher quality. I really liked the fact that the scope cost about $100 less than the Orion. So, if any of you are thinking of an 80mm ED glass refractor that is affordable, I highly recommend the Celestron C80ED.

作者: 文强 时间: 2007-5-10 09:03
译文我开始我的天文爱好者职业和爱上望远镜是在5年级的时候。我的老师 Cameron 女士热爱天文，所以她比其他老师花上更多的时间在天文上面。那是在56年以前，但是仍然和昨天发生的一样。从那以后我做了和拥有很多望远镜，我的第一个望远镜是Harry Rose Company 3寸反射镜。从来没有一个人听说到这个公司，但是我记得这个镜子很深刻。现在我拥有6个望远镜，包括 C8， C9.25，C11 和高桥的FS-128.

Orion 80 ED 有很多好的反应是因为有很多原因的。这里有很多原因吸引我去购买这个镜子，我发现几乎为零的色差。十分有趣的是一天晚上我和我的朋友一起观星，他用他的TV85 我用 Orion 80ED，他后悔花那么多钱在TV上面。

我喜欢上Celetron的80Ed 是在我看到他们网站上面的介绍之后，在他们卖 Synta之前。当时很多公司都在生产 80Ed，我发现 Orion 的80ED和 C80ED的镜片可能是一样的，我不假思索的预定了C80ED在他们网站上面然后在4天以后收到镜子。

当我打开包装的时候，发现镜子包装得很好，25mm PL 目镜和45度天顶镜分别用盒子包装放在物镜前面。对于一些原因可能是公司对不同市场的要求，C80ED定位是观景镜。这就难怪我不能在一些我经常关顾的卖家网站的天文望远镜分类里面看到这个镜子。后来我在他们的观景镜分类看到了这部镜子的介绍。

首先我发现这个镜子的做工很精细，镜子是用全金属制成。有些地方和Orion 80Ed不同：首先 OTA的外径是90mm,不像 Orion80ED是100mm。很有趣的是镜子的镜箍，和镜身吻合的很好，但是拆下镜箍时候会发现镜身给镜箍遮住的地方油漆比较暗点，镜箍是用插销装置来扣紧的。镜身还有鸠尾板和CG- 5赤道仪相吻合，还有1/4-20 的螺纹可以很装在相机三脚架上。当我用Stellarvue M1at-azmuth 来安放这镜子是那么的协调。
C80Ed 的调焦座是齿轮支架调焦座的而Orion是无齿调焦座。刚开始时候调焦座还算正常就是有点不够顺滑，当多调试一次以后镜子调焦座开始越来越顺滑。 C80ED支持2寸和1.25 寸的目镜还有一个2寸转1.25的接口。唯一一个塑料配件是防尘罩，当它和物镜向连接时候不是吻合的很好有点要掉下去的倾向，遮光筒有点短，所以这个不是一个很好的防尘罩配件。C80ED闪着黑色的光看起来很时髦。

寻星镜是6*30，里面的十字交叉丝。寻星镜支架很精细的安装了弹簧调剂的螺丝，这样调节寻星镜更加方便。寻星镜座可以和很多红点寻星器向匹配，包括 Orion EZ寻星器。我更加中意用红点寻星器来和这个镜子向匹配。 25mm PL 目镜和45度天顶镜对这个镜子也是很有用处的。但是我把他们放在一边当成高品质的配件。

当我装好镜子以后，第一个检查的是镜子的瞄准程度，惊奇的发现寻星镜和主镜是完美的吻合。从另一方面对于Orion 来说，使用前要都要进行准确的调节寻星镜。C80ED要做的就是直接放在星空地下观察。

我选用 WO的90度天顶镜和TV12mm进行镜子的处女航，等到日落时候很清除的观测到金星和木星。金星在几分钟以后落在地平线下面，木星的光环可以十分清晰的看到，没有任何色差，当我用 12mm Nagler 目镜和 Meade 8.8 UWA 提高倍数时候得到相当清晰的图像。

当天全部黑下来是时候开始了恒星测试，我是一个很认真检查他的望远镜的瞄准精度的人。所以我悬着8.8mm UWA来测试北极星，在第二次测试时候得到一个几乎完美的图像，图像的分界线很完美的焦距后和焦距前。恒星测试更加肯定了镜子的瞄准精度。镜子的光轴是完美的，还有就是这个是不可调整的，但是不是一个问题。当对焦时候，图像和背景很精确的表现出来。

我选择观察梅耶星体来结束这个晚上，我们在一年的任何时候都喜欢他们。球状幸运 M13和M42都很壮观的，哑铃状星云单线是那么美丽。双星团表现更加突出，发现 12mm Nagler是非常好的目镜来观测深恐星体对于这个望远镜来说的。F7.2 焦距是600mm的望远镜很容易锁定目标在红点寻星器的帮组下。

我有个机会和朋友对于 C80ED 和Orion 80ED用相同目镜观测相同的物体，两个镜子的表现差不多。我发现他的镜子那么的便携，他可以移走遮光筒和盖上塑料物镜罩。但是C80ED不会是那么容易的做这些事情。

综上所述，C80ED是真正的赢家， 90 OTA（上文提及的）看起来有点比C80ED短粗，全黑的色彩看起来很美丽。调焦座和防尘罩是具有很有的性能的，更叫重要的是这个镜子不 Orion80ED便宜了将近100美元，如果有谁向买ED镜子，我很热意推荐Celestron C80ED.

看到很多朋友都买 ED 镜子，就翻译了洋人的一个测评给大家看看，本来要选择 WO 的测评，但是都十分长没有那么多时间，就选了这个翻译一下。

很多翻译过来觉得自己念着都很拗口，第一次翻译这种测测评，可能会给大家一点帮助。

谢谢大家支持，看在小弟花了1个小时的份上。

作者: 我爱祖祖 时间: 2007-5-10 15:01
谢谢楼主的翻译，很有指导作用。ORION和C的80ED我都没有见过，不过据我了解，最好的80ED应该是TMB，可以说是没有一点色差的，即使在最苛刻的条件下测试，有同好比较过，TV85都根本不是对手！

作者: 文强 时间: 2007-5-10 23:08
祖祖据说你弄到一个 TMB的105 的头是吗？

花了多少米啊？

作者: 我爱祖祖 时间: 2007-5-11 21:53
不是105，是115，1.5W多吧

作者: 夜猫子 时间: 2007-5-11 21:56
标题: 回复 #5 我爱祖祖的帖子
比我厉害啊！

作者: 心鉴 时间: 2007-5-14 21:21
好有钱啊！~1.5W！~~

作者: skystar 时间: 2007-5-15 16:13

原帖由文强于 2007-5-10 09:03 发表
译文我开始我的天文爱好者职业和爱上望远镜是在5年级的时候。我的老师 Cameron 女士热爱天文，所以她比其他老师花上更多的时间在天文上面。那是在56年以前，但是仍然和昨天发生的一样。从那以后我做了和拥有很多 ...

辛苦兄弟了:D

作者: 文强 时间: 2007-5-20 12:03

原帖由 我爱祖祖 于 2007-5-11 21:53 发表
不是105，是115，1.5W多吧

开光了没有啊？

什么时候发写PP上来，要是感觉好的话，我也准备整一个

作者: ++0 时间: 2007-5-30 17:44
C80 用的两片53ED

作者: oldhen 时间: 2007-9-4 21:00
烧钱啊

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