P r i m a L u c e L a b S . p . A .
E A G L E C O R E U s e r M a n u a l
Introduction to astrophotography with DSLR and mirrorless cameras
Modern DSLR or mirrorless cameras have low cost, offer large sensors and generally have low electronic noise
even with the typical astrophotography exposition times: they are therefore perfect to take pictures of Universe’s
objects, recording weak details, even invisible to the naked eye. But the camera is not enough: because of the
Earth's rotation motion, objects in the sky continuously move and, in order to record the best images (which often
needs many minutes of exposition time), we need an high performance tracking system (
mount
) that tracks the
apparent movement of objects in the sky and thus allow us to keep the camera shutter opened. Modern mounts are
also
computerized
and thus allow to automatically slew to many objects and can be used in conjunction with
autoguide systems
that, automatically adjusting even the smallest mount tracking errors, allow to record images
even with very long exposition times keeping the stars perfectly tracked. EAGLE CORE allows you to control these
systems and, in a simple and fast way, record images through a DSLR or mirrorless camera, commanding the
entire setup through a smartphone or tablet.
Planetary/lunar and deep-sky astrophotography
Objects to image in the sky are obviously not equal and, above all, they have both apparent sky dimensions and
brightness very different. For this reason, when we speak of astronomical photography, we usually divide it into:
- planetary/lunar photography
- deep-sky photography
The first is performed by recording planets and the Moon usually at high magnifications (except when we want to
record the entire lunar surface in the same picture). Since the recorded objects have a high surface brightness,
shutter speeds required for this kind of imaging are generally low (even fractions of second) and the autoguide is
not necessary (since the automatic tracking feature is sufficient to track the expositions correctly).
Moon recorded with apochromatic refractor, Nikon D5600 DSLR and EAGLE CORE
Deep-sky astrophotography is performed on nebulae, star clusters, and galaxies that always have a very low
brightness and that, sometimes, may have large apparent dimensions in the sky (even larger than the Full Moon
size). For this reason, they can be photographed not only with telescopes but also with telephoto lenses and
always require very long exposition times. In this case, the use of autoguide (page 96) is essential to keeping the
stars perfectly tracked in the picture.
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