Another one of these ETXs, yes, in fact! Every telescope has it's own sky... you might have heard that before, I guess. So, what's the ETX-90's sky in Joachim's view. It is a solar-system scope! And why not, at least our sun is an interesting target (see the other hobby on this site) to count spots and stuff.
The ETX-90 (used) came with the obligatory 26mm Super Plössl, a 12.4mm Super Plössl, a straight “finder” and an angled “finder” (both of these are rather “searchers” than “finders”), EC-hand-box (no Autostar!), the table “tripod” legs, a travel case and an JMB Identi-View class A solar filter. And, guess what, this setup is my main and only solar telescope (maybe a PST can take it's place sometime).
In terms of portability, this telescope is unbeaten in my collection.
What mechanics are concerned, I do not like
the clutches (see ETX-125). Especially the declination (ups, I wanted
to wright altitude) clutch is not comfortably usable, the Mak has a
little bit of an unbalanced weight-ratio towards the object-side.
Tracking is loud, sounds like grggrrrrrrgrrrrr, slewing is even
worse, sound like a coffee grinder.
The focuser is a little bit
stiff. Focusing is done easily though.
For sake of packing I am
using the straight finder-scope. It's hard to look through it,
usually, the eye-relieve is quiet short, but nothing obstructs the
regular use of the main telescope even with a shorter focal length
eyepiece. The angled view-searcher (see above) likes to mate with
your left eye, if your right eye is dominating. (The dominant eye is
the one you normally use to look into tele- or micro-scopes and you
mainly use for distant vision).
Performance: Optically this scope is fine.
Good contrast on bright objects, just as you expect from a Maksutov
design. Saturn, Mars, Jupiter, Venus ... even Moon ;-o ... are “good
night” objects. Is there something wrong with the lingual
stress?! Kellner eyepieces of shorter focal length fit the scope
fine.
With the solar filter and a 25mm MA eyepiece sun is a
perfect day-dream! Larger spots even seem to show a surface relief
structure. The EC-hand-box makes a perfect combination with the solar
scope setup, as it is simply tracking, whatever moves in certain
velocities; the sun is not an object in Autostar controllers...
SO,
what's about deep sky and darker? Not much, at least from light
polluted places like Rijswijk... Yes, the core of M31 is visible, so
is some of M42. Open clusters such as M35, M36, M37, M38, NGC869 and
NGC884 are visible, but are not really revealing their beauty.... not
really.
The verdict: the ETX-90 is my solar system scope, day and night. It is also a scope which is easily carried around.
Last modified March 1st 2005