Maksutov Cassegrain question

wrote in message
...
I am just getting into astronomy and have already obtained a pair of
binoculars and am learning about getting around in the night sky. I
am also interested in obtaining a telescope at some point and have
become interested in Maksutov Cassegrains. I have seen some
conflicting infromation about collimation. Do these ever need to be
collimated? What would be a good choice for a beginner?
Yes, they do need collimation.
The point is that most of the smaller examples (scopes like the ETX90), have
the assembly so well stuck together, that changes in collimation are rare,
hence it is made a 'factory' adjustment. However larger versions, will have
collimation systems of some sort.
Depends what you want to do.
For instance, _for it's size_, scopes like the ETX90, are nice little units,
especially for the price. However for the same sort of money, a
significantly larger Newtonian, can be bought, and this will outperform the
smaller Mak for just about everything. Most 'rules', about 'which scope is
best for what', end up having lots of exceptions. So the 'best' small scope,
is probably an APO refractor, _but_ the cost is such, that for the same
money, a much larger scope using simpler technology (like a Newtonian), will
be available, which will see more. Maksutov models, generally, have quite
high focal ratios, which can be considered to make them relatively 'good'
for planetary observations, but conversely, limits the field of view for
deep space objects.
There are a series of 'rules', which might be worth bearing in mind beyond
these comments:
1) Aperture rules.
2) Better a small scope that is used, than a large scope, that is stuck
indoors...
The Mak tends to 'win' over most other designs, on it's 'useability', but
you should have a look at something like a larger Dobsonian mounted
Newtonian, as the best 'value for money' larger scope design around, to see
if you could cope with something like this. You will see more.

Best Wishes

They don't require frequent collimation, and often for casual observers
don't
require any out of the box, although you SHOULD check for this once you
get your scope. But once they're collimated they stay that was pretty well.

I think that they are a good beginner's scope; easy to maintain, give good
views. Be aware that you need to protect these scopes from the daytime heat
as they take sometimes an hour or more to cool down, and until they do, the
seeing is not good through them (thermal currents in the tube caused by the
heated optics).

Good Luck !
--- Dave

--
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Never be afraid of trying something new for the love of it.
Remember... amateurs built the Ark.
Professionals built the Titanic!


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wrote in message
...
I am just getting into astronomy and have already obtained a pair of
binoculars and am learning about getting around in the night sky. I
am also interested in obtaining a telescope at some point and have
become interested in Maksutov Cassegrains. I have seen some
conflicting infromation about collimation. Do these ever need to be
collimated? What would be a good choice for a beginner?

wrote in message . ..
I am just getting into astronomy and have already obtained a pair of
binoculars and am learning about getting around in the night sky. I
am also interested in obtaining a telescope at some point and have
become interested in Maksutov Cassegrains. I have seen some
conflicting infromation about collimation. Do these ever need to be
collimated? What would be a good choice for a beginner?

All telescopes need to be collimated at some point in their life.
Usually, quality instruments (like most of the Mak-Cass) need to be
collimated just once every several years (I have one Mak-Cass that was
collimated years ago and never ever touched again). As a starting
point you could get a 5"/6" MCT, the russian ones being a fair
compromise between price and performance (usually very good
performance indeed). Check with ITE their offers if you live in the
US.

Andrea T.

My Astronomy Pages at:
http://www.geocities.com/andreatax