Takahashi e-130D, Instruction Manual

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What is the ε-130D?
■Optical System
Newtonian reflector cannot produce a flat
field like a four element Pezval refractor
for imaging. A hyperbolic primary with a
flat –field corrector can produce a field
that is also free from spherical aberration
and coma. This system is called the ε
Series by Takahashi.
■ε Optical System in Digital Age.
The ε-130D uses an advanced
corrected hyperbolic optical design. The
newly designed doublet corrector
produces an image circle that will cover
full frame DSLR and CCD cameras with a
stellar size of under 10 μ m across the
entire field. The image size is comparable
to the ε-180ED. The spot size in the
center of the field is 1/3
rd
small than the
original ε-130. The original four element
corrector did not have the ability to cover
a full frame image like the ε-130D does.
The Effective Focal Ratio of f/3.3 produces
a 5.9° image at 430mm. The OTA weighs
only 10.8 lbs. and is perfect to transport
anywhere in the World. The ε-130D is a
high performance optical system.
■Takahashi Mirror Making Technology
Takahashi has been producing hyperbolic
mirrors about 30 years. They have
improved their production procedure to
produce the highest quality hyperbolic
primary mirrors. Now the ε-130D has
evolved into one of the most modern
optical systems in the telescope industry.
■Secondary Mirror Offset
In order to achieve the maximum
illumination, the secondary mirror must
be offset from the primary mirror optical
axis to produce the best possible
illumination for the image. As the speed of
the optical system increases, so does the
offset. The oversized secondary mirror has
been offset to produce the maximum
illumination for the image.