Setting up a telescope to polar alignment - problems with Bresser Skylux

I have recently been bought a telescope. I am new to astronomy and
would appreciate any advice I have on setting it up. It is a Bresser
Skylux with a German mount and needs to be set up with polar alignment.
The instructions are a little unclear (to me)

There is a section on "Handling - Adjustment"

It tells you to set the latitude, no problem.

Setting the declination axis - should this be done here, before
attempting
polar alignment? Later, in the next section, it tells you to set the
declination
scale to '9' i.e. 90% AFTER polar alignment. This is confusing me.
If you do set the declination to 90% then this moves the telescope tube
as
well, is that correct? It then says that your telescope is pointing to
the
celestial pole.

There is then a section on "Handling - Polar alignment"

You have to face the telescope north, no problem. It then says the
whole
set up should look like figure 28, which is a picture of the telescope
pointing straight ahead with the tube and the weight forming a vertical
axis. However if I have set the declination
to 90% as in the previous section then won't the tube be pointed at an
angle
to the mount, not face front as in the illustration?

It then says to find Polaris and then set the delination scale to 90%,
but
won't this point the tube away again?

Sorry I'm confused now.

I haven't tried this out outside as it is too cloudy but I'm not sure
if
I understand what it is I'm trying to do.

Anyway thanking you in advance for any help you might be able to give.

Gary

garyray wrote:

I have recently been bought a telescope. I am new to astronomy and
would appreciate any advice I have on setting it up. It is a Bresser
Skylux with a German mount and needs to be set up with polar alignment.
The instructions are a little unclear (to me)

'Setting up' for visual (as contrary to astrophotography) use is simple.
Tripod: set it up roughly at level

The mount has four adjustment knobs/screws.
The 'rough' ones;
1. for altitude
2. for azimuth

1. The altitude most likely has a scale from 0 to 90 degrees. This is used
to raise/lower the altitude.
Set this one to the same the latitude as where you intend to use your scope.
Given a proper polar alignment, this is not adjusted during the observing
session.

2. The azimuth most likely has no scale. This is where you can adjust your
mount east-west/left-right. Set it to 'middle'. That is, so you can
adjust it 'left-right' as much as possible. If you assume this is a
pointing device, these are the adjustment knobs/screws you use to 'point'
your *mount*'s axis to the north. (not your *scope*, that is...) Given a
proper polar alignment, this is not adjusted during the observing session.

The main idea of the two above adjustments is to point the RA axis to the
celestial pole (north or south).



3. for declination (DEC). This means how 'high' in the sky...
This adjustment will have a fine adjustment knob.
Don't worry about it now...

4. for right ascension (RA). Also have a fine adjustment knob. This is the
main adjustment, and given perfect alignment, this is the only adjustment
knob you must use to follow an object's apparent movement across the sky.
If you have no motor, this is done manually. To keep on object in the
center of your field of vision, you need to turn this knob so as your
scope moves clockwise in the speed of one complete turn in about 24 hours.
This knob is the main idea of the construction of the equatorial mount. (in
practice you just move it ever so slowly, once in a while... ) For this
to work, you have to have your mount (roughly) polar aligned. (and if it
isn't exactly, you adjust for this fault with your declination (DEC) fine
adjustment knob. (The 'object' will then be drifting 'up' or 'down', slow
or fast, depending on the 'fault' in polar alignment)

Rough polar alignment is simple but somewhat hard to explain without
pictures.

Try www.google.com. Put 'polar alignment' in search field, and you will get
a lot to read. Some good and some not so good. This one has a good
picture that should make you understand the basic idea.

http://telescopes.com/faq/Polar-Alignment.html

Thanks for your help.

I think I'm slowly getting to understand this and will print off your
message to reexamine what I'm doing. I will also have a look at the
site you suggested.

Gary


Iordani wrote:
garyray wrote:

I have recently been bought a telescope. I am new to astronomy and
would appreciate any advice I have on setting it up. It is a Bresser
Skylux with a German mount and needs to be set up with polar alignment.
The instructions are a little unclear (to me)

'Setting up' for visual (as contrary to astrophotography) use is simple.
Tripod: set it up roughly at level

The mount has four adjustment knobs/screws.
The 'rough' ones;
1. for altitude
2. for azimuth

1. The altitude most likely has a scale from 0 to 90 degrees. This is used
to raise/lower the altitude.
Set this one to the same the latitude as where you intend to use your scope.
Given a proper polar alignment, this is not adjusted during the observing
session.

2. The azimuth most likely has no scale. This is where you can adjust your
mount east-west/left-right. Set it to 'middle'. That is, so you can
adjust it 'left-right' as much as possible. If you assume this is a
pointing device, these are the adjustment knobs/screws you use to 'point'
your *mount*'s axis to the north. (not your *scope*, that is...) Given a
proper polar alignment, this is not adjusted during the observing session.

The main idea of the two above adjustments is to point the RA axis to the
celestial pole (north or south).



3. for declination (DEC). This means how 'high' in the sky...
This adjustment will have a fine adjustment knob.
Don't worry about it now...

4. for right ascension (RA). Also have a fine adjustment knob. This is the
main adjustment, and given perfect alignment, this is the only adjustment
knob you must use to follow an object's apparent movement across the sky.
If you have no motor, this is done manually. To keep on object in the
center of your field of vision, you need to turn this knob so as your
scope moves clockwise in the speed of one complete turn in about 24 hours.
This knob is the main idea of the construction of the equatorial mount. (in
practice you just move it ever so slowly, once in a while... ) For this
to work, you have to have your mount (roughly) polar aligned. (and if it
isn't exactly, you adjust for this fault with your declination (DEC) fine
adjustment knob. (The 'object' will then be drifting 'up' or 'down', slow
or fast, depending on the 'fault' in polar alignment)

Rough polar alignment is simple but somewhat hard to explain without
pictures.

Try www.google.com. Put 'polar alignment' in search field, and you will get
a lot to read. Some good and some not so good. This one has a good
picture that should make you understand the basic idea.

http://telescopes.com/faq/Polar-Alignment.html

On Fri, 20 Oct 2006 07:28:07 -0700, garyray wrote:

I have recently been bought a telescope. I am new to astronomy and
would appreciate any advice I have on setting it up. It is a Bresser
Skylux with a German mount and needs to be set up with polar alignment.
The instructions are a little unclear (to me)

There is a section on "Handling - Adjustment"

It tells you to set the latitude, no problem.

Setting the declination axis - should this be done here, before
attempting
polar alignment? Later, in the next section, it tells you to set the
declination
scale to '9' i.e. 90% AFTER polar alignment. This is confusing me.

You have to keep in mind that in doing a polar alignment, you are setting
the MOUNT, not the scope. Once the MOUNT is polar aligned, the SCOPE will
be able to track the stars (or at least it will be oriented correctly to
do so).

The declination axis is of no importance in polar alignment. Once the
MOUNT has been polar-aligned, you can point the SCOPE at the celestial
pole and THEN set the DEC setting circle to 90 degrees, and lock the
little setting circle down (if it doesn't rotate independently of the
scope and the mount, then you need to locate the set screw or whatever
they're using to lock it and UNLOCK it. You will never have to fuss with
the setting circle on dec again, unless you disassemble the mount for
repairs/overhaul/fun(?).



There is then a section on "Handling - Polar alignment"

You have to face the telescope north, no problem. It then says the whole
set up should look like figure 28, which is a picture of the telescope
pointing straight ahead with the tube and the weight forming a vertical
axis. However if I have set the declination to 90% as in the previous
section then won't the tube be pointed at an angle to the mount, not
face front as in the illustration?

Try twisting the DEC setting circle while holding the scope. If it won't
turn without moving the scope, you'll have to loosen it, turn the scope to
face the North Celestial Pole (if you're n of the equator)and then turn
the loose setting circle to read 90 degrees, and THEN lock it back down so
it turns with the scope once again.


SO, in summary,

1.) plop the tripod/mount down so the RA axis (polar axis) is facing
north, and make sure it's level.
2.) check the latitude scale or angle to make sure it is set for your
latitude.
3.) adjust the azimuth knobs (if any are present) at the base of
the mount to turn it more precisely toward the NCP. If there are no
azimuth adjusting knobs, then just rotate the entire tripod/mount so it's
as close to the NCP as you can get it. The NCP isn't the same as Polaris,
but Polaris is close enough for visual work.
4.) Put the scope on the mount.
5.) Orient the scope so it's facing north with Polaris in the field of
view.
6.) Unlock the DEC circle set screws (or whatever) and rotate the Dec
circle so it reads 90 degrees. You'll be 1 degree off, but worry about
that later. Tighten the set screw again.
7.) find an object or star with a known RA and DEC coordinate. Center this
star in the field of view with a high powered eyepiece. Turn on the
tracking motor, if any.
8.) Loosen and adjust the DEC circle again to read the same as the DEC
coordinate for that object.
9.) Have a cup of tea.

Hint: Mark the location of your tripod legs on the ground, so the next
time you go out to observe, you won't have to fuss with all these settings
very much.

All of the above, with the exception of the tea, should take less than 5
minutes, once you are accustomed to it. You could save some time by
putting the water on boil before you carry the scope out to the garden.

Have fun and Clear Skies,
Uncle Bob
Fairfax, California

Bob,

thanks. This looks like something I can understand. I think part of my
problem is the dodgy translation of the German instructions. Anyway,
I'm hoping for some clear skies but as this is firework season over
here (Eid, Dawali, then Guy Fawlke's Night) I might have to wait a
while.

Once again thanks for the help.

Gary

Uncle Bob wrote:
On Fri, 20 Oct 2006 07:28:07 -0700, garyray wrote:

I have recently been bought a telescope. I am new to astronomy and
would appreciate any advice I have on setting it up. It is a Bresser
Skylux with a German mount and needs to be set up with polar alignment.
The instructions are a little unclear (to me)

There is a section on "Handling - Adjustment"

It tells you to set the latitude, no problem.

Setting the declination axis - should this be done here, before
attempting
polar alignment? Later, in the next section, it tells you to set the
declination
scale to '9' i.e. 90% AFTER polar alignment. This is confusing me.

You have to keep in mind that in doing a polar alignment, you are setting
the MOUNT, not the scope. Once the MOUNT is polar aligned, the SCOPE will
be able to track the stars (or at least it will be oriented correctly to
do so).

The declination axis is of no importance in polar alignment. Once the
MOUNT has been polar-aligned, you can point the SCOPE at the celestial
pole and THEN set the DEC setting circle to 90 degrees, and lock the
little setting circle down (if it doesn't rotate independently of the
scope and the mount, then you need to locate the set screw or whatever
they're using to lock it and UNLOCK it. You will never have to fuss with
the setting circle on dec again, unless you disassemble the mount for
repairs/overhaul/fun(?).



There is then a section on "Handling - Polar alignment"

You have to face the telescope north, no problem. It then says the whole
set up should look like figure 28, which is a picture of the telescope
pointing straight ahead with the tube and the weight forming a vertical
axis. However if I have set the declination to 90% as in the previous
section then won't the tube be pointed at an angle to the mount, not
face front as in the illustration?

Try twisting the DEC setting circle while holding the scope. If it won't
turn without moving the scope, you'll have to loosen it, turn the scope to
face the North Celestial Pole (if you're n of the equator)and then turn
the loose setting circle to read 90 degrees, and THEN lock it back down so
it turns with the scope once again.


SO, in summary,

1.) plop the tripod/mount down so the RA axis (polar axis) is facing
north, and make sure it's level.
2.) check the latitude scale or angle to make sure it is set for your
latitude.
3.) adjust the azimuth knobs (if any are present) at the base of
the mount to turn it more precisely toward the NCP. If there are no
azimuth adjusting knobs, then just rotate the entire tripod/mount so it's
as close to the NCP as you can get it. The NCP isn't the same as Polaris,
but Polaris is close enough for visual work.
4.) Put the scope on the mount.
5.) Orient the scope so it's facing north with Polaris in the field of
view.
6.) Unlock the DEC circle set screws (or whatever) and rotate the Dec
circle so it reads 90 degrees. You'll be 1 degree off, but worry about
that later. Tighten the set screw again.
7.) find an object or star with a known RA and DEC coordinate. Center this
star in the field of view with a high powered eyepiece. Turn on the
tracking motor, if any.
8.) Loosen and adjust the DEC circle again to read the same as the DEC
coordinate for that object.
9.) Have a cup of tea.

Hint: Mark the location of your tripod legs on the ground, so the next
time you go out to observe, you won't have to fuss with all these settings
very much.

All of the above, with the exception of the tea, should take less than 5
minutes, once you are accustomed to it. You could save some time by
putting the water on boil before you carry the scope out to the garden.

Have fun and Clear Skies,
Uncle Bob
Fairfax, California

Gary you're getting some useful advise. Once it's set up ok eg polar aligned, you should mark the ground where the three leg lay so next time you've only got to plonk it down and you're ready to go! Enjoy your new scope - my review of it, with many pic, at http://www.astroman.fsnet.co.uk/skylux.htm

Nytecam 51N 0.1W