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3. Angle Measurement
“Face-1” and “Face-2” Measurement
The term “face-1” refers to observations made with the vertical circle
positioned to the left of the telescope eyepiece. Likewise, “face-2”
means the vertical circle is positioned on the right.
CAUTION
■
Be careful not to insert your finger between the telescope and
instrument standard when rotating the telescope.
•
Mechanical constant error (except a few errors such as vertical axis error)
can be effectively cancelled out by averaging the values in face-1 and
face-2.
Nikon
Face-1 measurement
Face-2 measurement