SKY-WATCHER Star Adventurer 2i Instruction Manual page 19

An equatorial mount rotates to
prevent star trailing in your photo
by precisely countering Earth's
Rotation Milky Way Galaxy revealed
through a long exposure astrophoto
with precision tracking
The Need For Tracking
In your now, nicely exposed photo, the stars don't
look like stars anymore. they look like little lines and
arcs of variable lengths! The problem here is called
trailing, and it becomes more noticeable as the
focal length of your lens and/or your exposure time
increases.
You might think that trailing is due to the movement
of the stars, but it's not. It's due to the movement of
your camera as it records those distant stars over
the course of that exposure. Your camera is moving
because it is sitting on a tripod that is sitting on the
Earth, and the Earth is rotating. This motion causes
the stars, which appear to be fixed in space from our
perspective, to appear to move relative to us, and
more importantly, to our camera.
Star Adventurer 2i overcomes this challenge by
moving your camera to precisely offset the effects of
Earth's rotation while a sufficiently long exposure of
the night sky is being made. Star Adventurer 2i's
tracking capability keeps a specific area of the sky
impinging upon the same part of the camera sensor
throughout the exposure. So a star will fall on the
same set of pixels from the beginning through the
end of the exposure. The result is a well-exposed
photo of the night sky with pin point star images.
With Star Adventurer 2i, two of the biggest
challenges in doing astrophotography are simplified
and automated for you. Star Adventurer 2i's
camera control features enable you to take
exposures in excess of 30s each. Star Adventurer
2i's tracking ability keeps your camera on target to
produce pin point star images. As your skill level
in astrophotography progresses you can set Star
Adventurer 2i up to take multiple images of your
subject, then use advanced processing techniques
like stacking to make truly remarkable celestial
portraits.
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