Re: telescope alignment



On Mon, 8 May 2006 16:13:25 +0100, "mark"
<mark.cridge@xxxxxxxxxxxxxxxx> wrote:

Hi all,

I recently bought a 90mm telescope and I am having trouble finding anything
other than the moon!

Can anyone provide a link or advice as to how to line up the scope so I can
see planets?

The telescope I have is a skywatcher skymax and I am not sure how to use the
finder scope that it came with. Also the control for adjusting the scope on
its mount seem very hard to adjust.

Thanks in advance!

I can't really comment on the control for adjusting the scope except
to say - is there something that may be locking the mount and
preventing you from moving it freely?

On the finder front you need to line it up with the main scope at the
start of each session (and again if you accidently bump into the
finder in the dark). It's not too hard to do and the Moon makes a good
practice object. Here's how to do it...

With the finder firmly attached on the main scope, aim the main scope
at a bright object like the Moon. If the Moon isn't available you'll
have to line it up with a bright star. Make life easier for yourself
by using a low power eyepiece here (a 30mm or 40mm is fine for the
job, but shorter ones such can still be used). The shorter the focal
length of the eyepiece (written on the side of the eyepiece barrel
(normally!) the higher the power and the smaller the field of view. A
large field of view will give you a bit of slack when you are trying
to find a star in the eyepiece.

If you're still having trouble locking onto a bright star (Jupiter in
the south is good too), move your head around to the back of the
telescope tube and look above the tube. Line up the star so that it is
in line with the vertical centre line of the tube. Now, keeping at the
back of the tube, move your head to the side of the tube and line up
the star with the horizontal centre line of the tube. If both centre
lines are lined up, the object should be in the eyepiece field of
view.

Ok - all of this was just to get an object in the main telescope. Once
this has been done, lock the mount so that the object can't escape and
look through your finder. Twiddle the adjustment knobs, one at a time,
watching where the cross hairs of the finder move. If you can't see
the cross hairs very easily, a dim torch pointed across the front of
the finder will show them and, if it's really dim enough, your target
star.

Once you've got the finder lined up and checked the main telescope,
chances are the object will have moved out of the field of view of the
main scope (unless you're using a driven mount). Simply drag the
object back into the centre of the field of view of the main scope and
repeat the process with the finder.

After a while, you will get faster at the process and will be able to
do the line-up more-or-less in one go. It does get easier!
--
Pete
http://www.digitalsky.org.uk
.