Takahashi
FC-76D Objective Unit Review
I have already reviewed the FC-76D as a
complete telescope, so this is just a brief overview of the objective unit. So what is the FC-76D objective unit?
The version of the FC-76D with the fixed
dew shield and smaller focuser used to be available only as a complete scope.
Then, because it used the same 80mm tube and focuser as the FS-60C, Takahashi
released the objective part as an upgrade. Imagine cutting an FC-76D off past
the focuser, at the point where the objective of an FS-60C starts, then
threading it to fit in place of the FS-60C objective – that’s the FC-76D objective
unit.
Look at it either way – as a great way to
upgrade your FS-60, or a cheap way to buy an FC-76D (though it’s not as cheap
as it once was – I guess Tak’ weren’t selling many
complete FC-76s!)
Strangely, the FC-76DC will now only be
available as a split tube, just as if you’d got an FS-60C and fitted the
objective unit. The reason is that being able to thread it in half makes the
FC-76 much more transportable (including in carry-on luggage).
At
A Glance
|
Telescope |
FC-76D
Objective Unit only |
|
Aperture |
76m |
|
Focal
Length |
570mm |
|
Focal
Ratio |
F7.5 |
|
Length |
35mm |
|
Weight |
~1 Kg |
Data from Takahashi
What’s
in the Box?
Mine came in a ridiculously overkill
triple box that would likely have survived being thrown out of a DHL aircraft,
never mind a Parcel Farce [sic] truck.
Design
and Build
Not much to say here, except the
threads are well made and it’s easy to avoid cross-threading if you are
reasonably careful (always thread the
scope together vertically). Takahashi paint colours change slightly, so the
white enamel might not be an absolutely perfect match: mine was pretty close
despite nine years between the manufacture of the FS-60C and the FC-76 Obj unit. Note that I struggled to get the original
objective to unscrew from my FS-60C first time.
Complete FC-76DCU from an FS-60C and FC-76D
Objective. Note the slightly different paint tones: the FS-60C is slightly
whiter.
The objective unit comes with end caps
to blank the tube when you are not using it. It also comes with a manual and a
replacement serial number plate, so your FS-60C becomes just like a ‘proper’
FC-76 bought as a complete scope.
Fitting the serial plate was easy. The
plate comes flat, but bends into shape as you tighten those screws.
Optics
Optics are
the standard excellent 76mm F7.5 fluorite doublet. For other details on how the
FC-76D performs, see the main FC-76DCU review.
Tube
The tube is
painted ultra-flat camera black inside and contains a single knife-edge baffle.
Focuser
The focuser will only be as good as the
one from your FS-60C.
You could, of course, just buy the
objective unit along with the tube Takahashi sell to upgrade an FS-60C to an FS-60CB,
then fit an aftermarket focuser from the likes of Moonlite
or Starlight Instruments.
Doing this would be a cheaper
alternative to buying a complete FS-76D and then upgrading the focuser, if that’s
what you intend to do (though Tak focusers are pretty
good, you might want the extra travel, load capacity or microfocus
that a Feathertouch or Moonlite
would give). At current prices, the saving of buying the objective instead of
the whole OTA should cover the cost of your new focuser.
Summary
The FC-76D objective unit is clever
product that owes something to Borg’s modular approach to making scopes. It is
an easy fit upgrade, with the only sticking point (literally) being the FS-60C
objective which may be a struggle to get off first time. Also, take reasonable
care when you thread either objective on and off: cross-threading would be bad.
The FC-76D Objective Unit is a simple
and (for Takahashi) cheap way of upgrading your FS-60C to a very much more
capable scope. Alternatively, buy it as a shortcut to an FC-76D with an
after-market focuser. Highly recommended.
By Roger Vine, Jan 2018.
