OPTICAL FEATURES
CCA‐250 uses a parabolic prirTlary rnirror
and a spherical secondaryr Which are easier
to produce′ resuiting in an ideal optical sys‐
teln producing corrected images、 〃
ithout
astigrnatism.
丁his optical design is an original and is an
advance from the senli‐Ritchey Chretien de‐
sign lTlaking the curves ofthe primary and
secondary same radius so as to rnake the
total su「l of Petzval zeroo MoreoveL the 3‐
element corrector can make the field per‐
fectly flat surpassing the BRC design.
Optical perforinance atf/5′ the CCA‐250 can
produces a 50rnrn image circle、〃ith less
than 6‐ rrlicron image in the centeL able to
easily cover a mediun∩ forrnat and larger
CCD with a totalimage circle 88mm atf/5.
丁
his iarge image circle will also be able to
handle 67 size CCDs when they become
avallable in the rnarket.
丁
he FnOSt remarkable feature of the CCA‐
250 is its ability to be a tri‐ focus astro imag‐
ing platforrn using the dedicated reducers
and extender.丁 he CCメい250 can be used at
the native f/5′ f/3口 6 1rvith the Reducer‐ CR
O.73X and f/7.5 with the Extender‐ CR l.5X′
which have been developed for the
Takahashi′ s original Mewlon― CR optical
systems.Moreoveら in order to cover the
largerirnage circle of future CCDs′ a dedi―
cated 645 Reducer‐ CA which produces
60mrn circle with less than 10‑rnicron irn―
ageis now under development.
An ASCOM Compliant Auto Focus:ng Sys―
tem is standard.FocusMax and lⅥ axilTIDL
can be used、 Ⅳ:th this system to control criti‐
cal focusing口 An ASCOM compliant dr er
can be downloaded from the Takahashi
website.
Please access:
[htt p://WWwatakahashilapanecOm/
supporteohtml]
to download the ASCOM compliant driver
forthe Active Focus systelTl ofthe CCA‐ 250.
Cooling Systeln:
3 cooling fans are provided on the rrlirror
ceH cover ofthe tube assembly。 (Э n/off Op‐
eration forthese fans is contro‖ ed automati―
cally by ASCOM compliant software or
manua‖y口 ln orderto run these fans′ three
sensors are provided to rnonitor the teln‐
peratures ofthe primary mirroL the inside
and outside temperatures ofthe rnain tube.
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