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本帖最后由 quantedge 于 2020-1-20 21:29 编辑
几年前发现同样的现象,加了增倍镜之后,出瞳距离增加了,感测舒适度增加了。用82度24mm天文目镜白天观景容易出现“黑豆”现象(kidney beam effect),加了2X增倍镜之后好像这种现象减轻,舒适度增加。
The Barlow will noticeably increase the eye relief of the same eyepiece.
Most types of Barlows will increase the eye relief of an eyepiece. The exceptions to this are telecentric devices like Powermates which do not change the eye relief at all. Shorty Barlows increase the eye relief more so than standard barlows of the same magnification factor. Longer focal length eyepieces wil experience more of an eye relief increase with a given Barlow than shorter focal length eyepieces.
How much the eye relief changes is more a function of the focal length of the barlow (shorter barlows yield more effect) and of the eyepiece (longer eyepieces have more change in the eye relief) than the magnification factor.
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