new in CCD imaging and the purpose of this section
is not to give a general tutorial for imaging with
the DSI, but provide you with a description of
how I use this CCD camera with my setup. For more
information about the DSI see the section "related
links" at the bottom of this page.
The Meade Deep Sky
Imager is a low cost CCD camera from Meade
company. This camera is part of a package with a software
, called Autostarsuite and some accessories, ready
to produce black & white or color pictures.
With a configuration such as mine it is recommended
to add a focal reducer between the telescope
and the CCD camera. This configuration offers a
large field of view to shop deep sky objects.
We can understand below why this accessory is so important.
Why is it necessary to use a FR with the Meade f/3.3
In fact, there are two main reasons to use
- First of all with a schmidt-cassegrain telescope
at f/10, the field of view displayed through the camera
is too small to imaging deep sky objects like
nebulas or galaxies. Thanks to the FR, the focal of
the telescope will be reduced from f/10 to F/6.93,
F/5.23 or F/3.52 depending on how the T-SCT adapter
- Secondly, the fast f/ratios that are produced with
the FR greatly reduce exposure times as well
as guiding requirement of the telescope's tracking
during exposure. In short, the less the focal ratio
is the less your time to imaging will be. Imaging
with short exposure time becomes possible with a telescope
in Alt/Az alignment.