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■Cool Down
The ε -130D uses an oversized φ 166
mm primary which requires a cool down
period for the temperature of the primary
mirror to equalize with the outdoor
temperature. This is especially true in the
colder winter.
It is advisable to take the instrument out
about one hour before it intended use to
insure temperature equalization.
■ Visual Observation
◆ Determining Magnification
The ε-130D is designed to be a flat-field
astrograph and as a result uses an
oversized
secondary
illumination. This larger secondary limits
the focal length of the lowest power used
to a 23mm or shorter focal length
eyepiece at 18.7x. This eyepiece will
provide the maximum field size. Any
longer focal length will cause vignetting
of the field caused by an oversized exit
pupil.
■Astro Imaging
Critical focus must be achieved to produce
a flat field image with pinpoint stars the
ε -130D was designed to produce. This
critical focus should be checked with each
new image.
Observation
◆Prime Focus imaging
The ε -130D is designed to be used at
f/3.3 and consequently has a very narrow
depth of field; this is a principle of optics.
Therefore, a fine focusing mechanism or a
computer controlled electronic focuser
will enable the ε -130D to produce the
10 µ m stars.
The ε -130D has been designed to be
used with a DSLR or CCD camera. The
output thread is Ø 55mm x.75 output
wide mount T-thread. There are a number
of wide mount adapters that allow the ε
-130D to be used with a DSLR or CCD
to
provide
camera. The wide mount camera adapters
cover all popular brands and the customer
adapter accept a number of CCD cameras.
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Camera Mount DX-WR
Camera Mount DX-WR
DSLR
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