 The FX series
features optics with lower focal ratios (F/4, F/3.7) made by Mike
Lockwood,
of Lockwood Custom Optics.
Extensive testing of these mirrors has shown that they perform as well
as longer focal ratio
mirrors on deep sky objects AND planets, but they have shorter eyepiece
heights.
Click on
this link for a very nice "review" of an 18" F/3.7 FX telescope,
posted by its happy owner.
So, if you
like the idea of spending less (or none!) of your valuable observing
time climbing
up and down a ladder, or you need a telescope with fast cool-down time
because you can't observe all night,
or you want a lighter-weight telescope with large aperture, then an
FX-series telescope may be for you.
Let's clarify
some of the facts about the FX models.
Hybrid
or Truss: The 14.5" F/4 FX is a hybrid
telescope,
featuring the hybrid truss, which can be left partially assembled for
faster assembly.
The 16.5" through 30" FX telescopes are truss telescopes, with the
standard Starmaster truss system.
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 Optics:
The 14.5" F/4 and 16.5" F/3.7 FX telescopes feature a 1.25"-thick Pyrex
mirror, weigh 20% less than 1.6"-thick mirrors, and 40% less than
2"-thick mirrors! They also hold 20% and 40% less heat, respectively.
These mirrors
cool more quickly than 1.6"-thick and MUCH more quickly than 2"-thick
mirrors, providing superb
performance in less than an hour! With a carefully crafted and
thoroughly tested mirror cell supporting the mirror, these optics show
no gravity-induced astigmatism, and optical alignment is held
accurately at all altitudes. (Click
here for the story about the origin of the 16.5" FX.)
The larger FX
mirrors also sit in the same type of carefully made mirror cell, but
the mirrors are thicker - the 18" and 20" FX mirrors are 1.6" thick,
the 24" is 1.75" thick, and the 28" and 30" mirrors are 1-7/8"-2" thick.
Hate
ladders? Look at this photo!
It is a picture of
6'2"-tall Rick observing near the zenith with a 24" FX telescope on the
second step of
an inexpensive, lightweight, easily transported stepstool. For most,
the third step
will allow them to safely view at the zenith with this telescope. For
the 14.5" and 16.5" FX models, you generally don't need a ladder!
If you are:
- 5'3" tall, you don't ever need a ladder for the 14.5"
F/4.0 FX.
- 5'7" tall, you don't ever need a ladder for the 16.5"
F/3.7 FX.
- 6'2" tall, you don't ever need a ladder for the 18"
F/3.7 FX.
- 6'2" tall, only a 6" step is needed to observe with a
20" F/3.7 at the zenith!
We recommend:
In the photo at
the top of this page, Rick is observing seated on the StarStep chair
with the 16.5" FX telescope
pointed nearly at the zenith! After a long day of telescope building,
Rick enjoys being
comfortable at the eyepiece of a superb telescope. Mike Lockwood,
optician for the FX series,
says
"I always
see more planetary detail when I observe while seated, because I am
more comfortable and I can hold my eye steadier at the eyepiece. I can
also observe comfortably for much longer periods of time, and catch
more of those wonderful steady moments when planetary detail becomes
exceptionally sharp." -Mike Lockwood
Video
Astronomy: If you've been contemplating trying video astronomy,
the FX-series telescopes
are some of the best-suited telescopes on the market. Video astronomy
is one of the fastest-growing
techniques in amateur astronomy. Short exposures are taken with a
high-sensitivity camera and displayed in
near real-time on a TV or computer monitor. Faint galaxies and nebulae
are revealed using exposure times
of only seconds, and groups of observers can all view the monitor at
the same time.
This technique
is ideal
for public astronomy, or for seeing faint and elusive objects, such as
the Horsehead Nebula or Pillars of Creation,
with small (or large) telescopes from light-polluted areas. Why are FX
telescopes ideally suited for this? Because the faster
the optical system (the lower the F/#), the shorter the exposure
required to reveal a
faint, extended object. The FX series
represents the most cost-effective telescope for video astronomy that
can also provide the highest quality large-aperture planetary images
for visual observing. John VeDepo has done quite a bit of video
astronomy and astrophotography with his 28" and 16.5" Starmasters, and
we have posted his online video astronomy and
astrophotography article, complete with lots of his images, all
obtained using modest photographic equipment.
Final
thoughts: While the
prices
of the FX telescopes are slightly higher than non-FX models because the
optics
are more expensive to manufacture, we hope you'll consider the many
advantages that the FX series
has to offer, such as compact size, fast-cooling optics, lighter
weight, all in a telescope built to Starmaster standards.
For more
information about the FX series telescopes, see the 14.5" FX telescope
information on the Hybrid Telescope Page,
and
the truss scope specifications and prices pages for other information
about all of the FX telescopes.
Starmaster
now offers an even more compact line of large telescopes with fast
cooling mirrors - the Super FX series.
Contact Rick if you have questions about which series is right for you.
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