My ETX 125 is the nicest telescope I’ve ever looked
through. At ScopeX 2004, the annual ASSA (Astronomical Society of
Southern Africa) telescope exhibition held in Johannesburg in late
April, I had a continuous queue of about 20 people waiting to view
Jupiter (with a borrowed 15mm Meade Plossl and 2x Barlow giving 250x
magnification), the longest behind any telescope. With an assortment
of scopes nearby (including a C8, LX90, various Dobs and small refractors),
I was told by many that the view of Jupiter through the ETX was the
best at the star party.
With its f/15 focal ratio and 1900mm focal length,
the ETX 125 would seem to be a specialist lunar and planetary scope.
It certainly excels on the Moon and planets with sharp, colour free
and detailed views but with the standard 26mm Plossl (73x), open
clusters and globular clusters are also easy and satisfying targets.
It is reported in the Cloudynights ETX forum that the ETX 125 loves
Konigs and Erfles which have wider fields than Plossls – I’ll
have to start saving…
To UHTC or not to UHTC?
Not having looked through an ETX 125 without UHTC
(Ultra High Transmission Coatings), I can’t personally comment
on how much of an improvement it makes – having said that
I must say that the views through my ETX are stunning and I feel
that the UHTC has to be contributing towards this. UHTC has been
reported to give a 10 – 15% improvement (Cloudynights Report,
7” Meade MCTs) in subjective visual testing, and a better
than 20% improvement (Arkansas Sky Observatory, 10” Meade
SCTs) in measured light throughput, so it does seem to be worth
the 10% extra expense.Using the ETX 125
Mechanically, the fork mount and tripod combination
seem well suited to the size of the OTA. Dampening time after vibrations,
even at high power (250x), is quick. The plastic outer shell on
the metal fork mount initially doesn’t inspire confidence,
but in actual use the fork mount is quite stable and the Alt-Az
operation always places the eyepiece and finder in a comfortable
viewing position. I haven’t tried the mount in equatorial
mode yet as I haven’t found the need to.
The motors seem noisy when slewing at 3 a.m. but from
10 metres away, you realize that they aren’t all that loud.
A “Quiet Mode” reduces the slewing rate (and thus the
noise) if the neighbours start to get rebellious. Tracking is visually
smooth and accurate.
The full system on the tripod can be carried in one
arm and as such is very portable.
The Autostar hand controller has a relatively shallow
learning curve but reading the manual is still advised. It is easy
to find objects by name or by Messier, Caldwell, NGC or IC number.
Before slewing to a target the Autostar will tell you it’s
magnitude, position and in which constellation it is. This is very
helpful, especially when many potential targets are lost in the
light pollution to my South, or the trees and house to my North
The “Tonight’s Best” guided tour
presents objects that I had either never thought of looking for
(47 Tucanae – wow!) or had never found before (the Lagoon
Nebula and the Teapot in the same field at 73x – wow again!).
A 15-minute quick look can easily turn into a 2 or 3 hour observing
session due to the convenience of the Autostar
The ETX requires some effort and attention to detail
to get it working well. Before starting an observing session you
need to calibrate the motors and then train them to compensate for
lag and backlash. The mount has to be level and true North aligned
and the tube must be leveled before you start the alignment procedure.
The more accurately you complete the manual setup, the more accurate
subsequent alignment and GOTO results will be.
So far it’s been all wine and roses but the
ETX is not without it’s faults. The major observing bugbear
on mine was the random “Motor Unit Fault” error that
occurred during tracking and then requires the resetting and realignment
of the telescope to continue. I won’t bore you with the potential
causes and solutions, but this has been an intermittent fault with
the ETX line since it was introduced nearly 10 years ago and it
occurred frequently enough on my scope to be more than a minor irritation.
In my case, replacement of the RA drive (see below) has solved this.
Two glaring omissions from the ETX package are a dew
shield and a bracket to hold the Autostar controller. The corrector
lens dews up rather quickly and although I have made a temporary
dew shield with black cardboard which works effectively, it won’t
win any prizes for elegance. The dew shield also stops stray light
from shining onto the corrector and reducing contrast - a major
issue for any backyard observer. A decent dew shield is essential
for grtting the best performance out of the telescope and is highly
The lack of bracket for the Autostar handbox is a
silly oversight by Meade, especially on a premium range such as
the ETX series.
The top element of the supplied 26mm Plossl is recessed
quite far into the barrel, forcing you to make full use of the approximately
15mm eye relief. I find I have to push the eyecup down and screw
my eye into the eyepiece to get the best view. Although this is
not really a problem, it is just different from my old 25mm Kellner.
Much has been written about the dinky 8x25 right angle
finder that isn’t complimentary. I find it works fine for
its intended purpose of centering an object that the Autostar hasn’t
placed in the eyepiece field of view - common during initial alignment
but seldom necessary during a GOTO observing session.
Meade UK’s Technical Support
Disaster struck quietly one Saturday evening when
the Jewel Box elegantly exited the field of view. Attempts to slew
in azimuth with the hand controller elicited only faint “cluck”
noises from the base of the mount. To cut a long story short, the
mounting holding the motor/gearbox to the worm gear assembly had
Meade UK were wonderful and within a week (and with considerable
help from my brother-in-law in the UK), I had a new unit installed
and the scope working again. Kudos to Meade UK (Broadhurst, Clarkson
and Fuller) for their rapid and informative responses to emails
and for the happy resolution of the breakdown.
The new motor unit also seems, so far, to have resolved
the “Motor Unit Fault” issue as this has yet to happen
since the repair.
Meade ETX 125 UHTC as an upgrade to a 90mm
As I’ve mentioned, we don’t get to look
through a lot of different telescopes in my part of the world. My
personal experience is very limited and I had little idea as to
how much better the ETX (or any other telescope) would be compared
to the smaller diameter Orion refractor.
The Orion 90 mm achromat (reviewed here on Cloudy
Nights) is a fundamentally good telescope. The f/10 optics are good
and it is mechanically simple and sound. Its biggest limitations
are the relative lack of light grasp (at f/10, false colour was
never really an issue) and the EQ-2 mount, which is a bit wobbly.
Is the ETX worth it’s 4x price premium?
Undoubtedly it is. Optically it is in a different
league to the refractor. With colour free views that are sharper
and crisper, it also takes magnification easier and is always a
pleasure to look through.
While I do fondly recall the ease and rapidity with
which the Orion could be set up as compared to the procedure required
for the ETX, the nostalgia quickly fades as the Meade effortlessly
whines it’s way quite precisely to target after target. The
setup difference is only about 10 minutes in reality.
Focusing at higher magnifications is far easier and
it snaps into focus with more authority than the refractor. Mechanically
it is more stable and the components are of better quality, especially
The GOTO capabilities are the cherry on top. I’ve
done my time trying to find DSO’s by star hopping. I find
GOTO adds a lot of fun to observing. It is also very informative
as each object has brightness, distance, size and other information
available on the Autostar screen, turning each observing session
into an educational experience. On my first “Tonight’s
Best” tour I was astounded at what was within reach of the
5” Mak, and amazed by the number of objects that were up that
I’d either never heard of, or had never found before.
Photography (with the Maxview 40 eyepiece and Minolta
D7i digital camera combination) in Alt-Az mode is a snap - and the
results are very pleasing to me. The picture below is the very first
image I took of the moon through the ETX - it has not been processed
in any way except to crop and resize it to fit on the page (no sharpening,
stacking, level, contrast or colour adjustment).
I haven’t mentioned collimation or cool down
time, both of which can be issues with MCT’s. I don’t
know much about star testing but the diffraction rings are identical
on both sides of focus so I assume the optical train is aligned
Nights are fairly warm (especially here on the coast
in Durban), therefore cool down times are not much of an issue as
the inside/outside temperatures probably don’t differ by more
than 5°C on most nights. Subjectively the views do improve slightly
as the observing session progresses, but the views at initial start-up
are very sharp in any case so I don’t bother with a cool down
period. Having said that I have had one cold night (OK, it was only
10°C) session observing the _ moon in which the image boiled
noticeably at high power.
Some mirror shift can be noticed while focusing but
it doesn’t detract much from the observing experience.
Meade’s $99 eyepiece offer
This arrived some four months after the ETX did due
to the considerable popularity of the offer and the backlog that
this created. It was worth the wait as it has extended the capabilities
of the ETX considerably.
The seven eyepieces, all in bolt cases and nestled
in the neat aluminium case, complete the set of Series 4000 Plossls
- starting at the 40 mm and ending with the 6.4 mm. This gives a
magnification range of 48x to 297x which suits the ETX well.
I haven’t managed to spend sufficient time with
all the eyepieces yet to form an opinion worth sharing, but the
15 mm is already a favourite.
No review of an ETX would be complete without mention
of Mike Weasner’s ETX site at www.weasner.com/etx---the
mother of all ETX sites. Here you will find the reference to the
Arkansas Sky Observatory UHTC comparison mentioned above along with
literally thousands of comments, articles and reviews covering all
things ETX---accessories, imaging, alignment techniques, troubleshooting
The Meade website (www.meade.com)
is nowhere near as useful to ETX owners but Meade does frequently
update the Autostar software. This is available for download and
is uploaded to the hand controller with a serial/RJ45 cable. The
ability to update is a very useful and powerful feature of the Autostar
system. The same cable allows your PC to control the ETX and I have
used SkyMap Pro 10 to easily do this, making for more Saturday afternoon
I do suspect the GOTO glow may eventually wear off,
but it will be years before I become blasé about the marvelous
Maksutov Cassegrain optics.
This is not a telescope for the beginner or casual
observer. The ETX demands your involvement if you are to get the
best out of it. Whether Meade intended it or not, the ETX is an
ideal hobbyist telescope that rewards your input and fine tuning.
The more you know about the ETX, the more you appreciate it’s