focal length ratio
常见例句
- For example, a telescope with a 2032mm focal length and an aperture of 8" (203.2mm) has a focal ratio of 10 (2032/203.2 = 10).
比如,望遠鏡的焦距爲2032mm,孔逕爲8英寸(203.2mm),則它的焦比爲10 (2032/203.2 = 10)。 - If you know the focal ratio but not the focal length, you can calculate it: focal length is the aperture (in mm) times the focal ratio.
如果你不知道焦距,衹知道焦比(focal ratio),你可以通過這樣計算的得到焦距:孔逕(單位是mm)乘以焦比就是焦距。 - Or, you can calculate the exit pupil by dividing the focal length of the eyepiece (in mm) by the focal ratio of the telescope.
或者,你還可以將目鏡的焦距除以望遠鏡的焦比來得到出瞳尺寸。 返回 focal length ratio