偶然发现个叫Fraunhofer doublet 的镜子，请教

799美刀，  看行星效果好吗？  价格是否合理？  多谢指点

SV 102 mm f-11 Refractor

This is what we consider to be the “ultimate achromat.” We start with a very accurate, fully multi-coated 102 mm f-11 Fraunhofer achromatic objective, mount it in a Stardust White, fully baffled tube, add dual rings, retracting dew shield, thread on cap and our own, highly rated 2.5” dual speed, rack and pinion focuser with 2” and 1.25” compression ring adapters. But we didn’t stop there. This telescope features a 4 3/4” threaded extension in front of the focuser. Remove this extension and you can use bino-viewers without the need for adapters of any kind. This will give you the widest, sharpest views through binocular viewers. We plan to make only two dozen of these instruments. Don’t delay!

                               
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好像不用这么贵吧。记忆中很多望远镜$报价比转换成¥后便宜的。这个价可不便宜。
其实这镜也就适合看行星。不如用卡镜。

整了半天就是个两片是普消，跟夫琅禾费爷爷有啥关系...

Fraunhofer（夫琅禾费）是德国著名的光学家、分光镜的发明人，Fraunhofer doublet 是指夫琅禾费结构的两片式折射物镜。
这款折射的外形很像裕众产的102F11普消（国内目前还没得卖），调焦座是锐星的2.5吋双速齿条调焦座，适合用来观测行星、双星等。

多谢楼上3位前辈的解答！！  

长焦的普肖而已

SV系列其实是很不错的结构。这个F11，其实很巨大的，不过这个焦距看行星，效果已经很不错了。制作精良的普消，素质不可小觑。这个799价格，还有特别的为双目设计。

都是有知识的人佩服

长焦行星月面利器啊，啊啊啊