Campanola CAN18 Instruction Manual page 13

• Astronomical twilight determination feature, which can estimate darkness
level of the sky and useful for sky watching. You can also find starting/
ending time of astronomical twilight using the altitude −18° line on the
transparent dial.
• Indication feature of direction and altitude of the Moon and moonrise/
moonset determination feature, which are highly needed for sky watching
and useful as a support of astronomical twilight determination. You can
see the approximate position of the Moon on the celestial sphere as well as
approximate determination of moonrise/moonset by reading the position
of the Moon with the 24-hour dial and the moonrise/moonset line on the
transparent dial. You can see influence of moonlight by referring to lunar
age, in addition.
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