Mars 2003 Telescope Comparisons:
Note: Since writing this comparison I've researched central obstructions in telescopes
and the merits of refractors vs. reflectors. One of the best explanations can be found at Thierry Legault's site. It is no surprise that the 5" Mak produces aesthetically pleasing views of the moon, while the
5" achromat yields sharper detail of low-contrast objects. The central obstruction on the Mak is even bigger than the
secondary itself; you can see an internal cone inside. This is typical for Maks; some even come with external obstructions
that can be removed. Without such extra obstruction the secondary cannot block incoming light from reaching the eyepiece
directly between the edge of the secondary and the inside of the internal eyepiece baffle. So high-contrast objects
like craters have excellent contrast, while low-contrast rilles are there but harder to find in the Mak than in the much cheaper achromat.
Of course the Mak is free of false color and produces high magnification with ease.
1. Meade 10" LX200 f/10 SCT: Top honors of the
four, as expected. With the mild temperatures cooldown has not been an issue. Even "quick" looks have been acceptably
steady, contrast seems very good with Mars surface coloration easily discernible and polar cap clear as day (even as it recedes
for the summer). Unfortunately I've had few opportunities to take astrophotos (see "Planets"). This scope handles
magnification very well and is a joy to use if you have time to set it up.
2. Meade 5" LXD55 AR-5 Achromat: Very good, somewhat
surprising. Normally false color issues hinder this scope on planets but Mars has a pretty narrow range of
color. Contrast was close to the 10" SCT and very pleasing. This scope is a little dimmer than the 5"
Mak (another surprise) but views tend to be steadier and resolution seems just slightly better.
This scope looks like a telescope is supposed to; I might be guilty of favoring it. Just don't aim it near
the zenith. Even if you clear the tripod legs you'll be laying on your belly to reach the eyepiece.
3. Meade 5" ETX-125EC Mak: Very good optically
as expected. It was a tough call to put the AR-5 ahead of it. This scope achieves high magnification more
easily than the AR-5, and produces more pleasing views, but the resolution isn't quite as good if you really scrutinize it.
This might be a cooldown issue; the Mak unfairly gets the grab-and-go treatment. It's also a little shaky and deserves
a better mount. The optional electric focuser helps a lot, but Meade should come up with an LXD55 Mak version since
many folks polar mount their ETX just to overcome motor vibration. Meade's 7" Mak is void of these shortcomings
if you can afford it, and would tolerate unsteady air better than the 10" SCT.
4. Orion 3.1" ShortTube 80 Achromat: Satisfying
views but a little short on magnification. Polar cap was easily discernible at about 125x (as high as I could go), used
this scope to monitor the shrinking size. This scope made Mars look the reddest due to its small aperture, and this
pleased the casual viewers the most. You can have this scope up and running in 60 seconds so it gets the most use.