动脉
发表于 2025-3-23 13:28:40
Formeln und Tabellen Maschinenbauwhere .. . focal length of objective lens or primary mirror; and ... focal length of eyepiece.
Lumbar-Stenosis
发表于 2025-3-23 17:46:10
Choosing Equipment,Two numbers, e.g. 10 × 50 or 11 × 80, designate a binocular. The first of these numbers is the magnification; the second is the diameter of the objective lenses in millimetres. For example, a 7 × 50 binocular has a magnification of ×7 and objective lenses of diameter 50 mm.
Filibuster
发表于 2025-3-23 20:08:42
Setting Up,In order to track an object successfully with a single motion, the polar (RA) axis of an equatorial mount must be parallel to the axis of rotation of the Earth.
ingestion
发表于 2025-3-24 02:02:01
Getting the Best out of Your Optics,To get the best out of a telescope for astronomy, it helps if you understand how it works. A telescope, when used for astronomy, serves three functions: it magnifies, it increases light grasp, and it increases resolution.
heckle
发表于 2025-3-24 04:14:31
Observation,The three components of good observing conditions are transparency, lack of sky brightness, and seeing. Understanding these components and the effect they have on observing will help you get the most out of your telescope.
conference
发表于 2025-3-24 07:14:10
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botany
发表于 2025-3-24 14:10:33
http://reply.papertrans.cn/17/1636/163553/163553_17.png
引起痛苦
发表于 2025-3-24 16:53:45
Formeln und Tabellen Maschinenbauhen warmer, moist air cools down, there will come a point where it is saturated and will begin to give up its moisture. The principles of dew reduction are then simple: reduce the amount of cooling of the optical surfaces and reduce the amount of warm moist air (e.g. breath) that comes into contact
肿块
发表于 2025-3-24 19:34:29
https://doi.org/10.1007/978-1-4471-0439-1Telescopes/Binoculars and Observing; astronomy; photography; positional astronomy; star; telescope
bleach
发表于 2025-3-25 01:04:29
978-1-85233-272-3Springer-Verlag London 2000