Jump to content

polar alignment, what next?

Calico Jack

By Calico Jack
in Welcome

Recommended Posts

Calico Jack

Calico Jack

Posted
Posted

Hi everyone, i feel a bit of a fool with this one.

I`ve had my small 60mm refractor for a couple of years, more or less just pointing and looking, not very satisfactory. i`ve decided to give things another try this year. My scope is on an equatorial mount, not motorised, i have polar aligned it. It now sits in my kitchen pointing north, I can see how it will follow objects with high latitudes, but how do i look at and follow, say a star rising in the east or directly above my location without undoing the alignment?

Its to clouldy tonight to take outside

Thanks CJ

Link to comment
Share on other sites
  • Replies 29
  • Created
  • Last Reply
brantuk

brantuk

Posted
Posted

Here's a rough "how to" for observing only:

1. Point the mount north using a standard compass

2. set the altitude scale to the latitiude at your location

3. Line up the main tube with the mount and lock the clutches

4. If lucky you will see the pole star in the finder. If not:

5. Adjust using the latitude bolts and az bolts only untill the pole star is in middle of finder.

6. Adjust further untill the pole star is in the center of eyepiece and finder.

7. Unlock the clutches and move to the desired object and re-lock the clutches.

8. Continue tracking using only the RA control.

Use a 25mm eyepiece for setting up - refine using 10-15mm if needed. Don't move the mount throughout or you'll have to start over.

This won't be accurate enough for photography but will be very useable for observing :)

Link to comment
Share on other sites
Calico Jack

Calico Jack

Posted
  • Author
Posted
Hi Jack and welcome

Just pointing north isn't enough, the mounts declination needs to be set to the latitude of your home location. To be fair, you do need to set it up outside to understand how it tracks objects.

Thanks John , i should have been more clear. My scope is aligned properly incl my home latitude. to view an object in the opposite direction , would i unlock the mount and spin to the object.( in effect turning the whole tripod) but keeping the alignment settings?

Thanks Jack

Link to comment
Share on other sites
carastro

carastro

Posted
Posted

Hi Jack,

i unlock the mount and spin to the object.( in effect turning the whole tripod)

Just to clarify: The tripod doesn't move. This should always be pointing at polaris. It is the mount that moves (the two parts which rotate on top of the tripod which holds the telescope). I suppose you could say "in effect".

If your scope is polar aligned, then turning the RA axis the telescope will rotate as the skies rotate. Turning the DEC axis moves up and down in declination.

Therefore if you have correctly polar aligned, you can release both the RA and Dec clutches and once you have found your object (not moving the tripod), lock the clutches again and you should then be able to rotate the RA control only and follow the object as the Earth rotates.

As said before this is best done outside.

Hope this helps.

Carole

Link to comment
Share on other sites
Patbloke

Patbloke

Posted
Posted
Hi Jack,

Therefore if you have correctly polar aligned, you can release both the RA and Dec clutches and once you have found your object (not moving the tripod), lock the clutches again and you should then be able to rotate the RA control only and follow the object as the Earth rotates.

As said before this is best done outside.

Hope this helps.

Carole

Carole, by clutches do you simply mean the locking wing nuts that hold the RA & DEC joints in position? I have polar aligned my scope many times but lost the plot a bit when I wanted to look at something behind me... I have watched several clips on Youtube which clearly demonstrate polar alignment, but they all seem to finish when the alignment is done.

How good would it be if there was a clip on there showing someone navigating around the skies using just the RA & DEC hinges/controls...

Link to comment
Share on other sites
blinky

blinky

Posted
Posted

Yes, you are correct, once you polar align, dont move the mount or the Alt/Az adjustment controls. You can unlock the Ra and Dec and swing them about to find your target but dont touch the Alt/Az ones or move the tripod.

Welcome to the lounge BTW!

Link to comment
Share on other sites
Patbloke

Patbloke

Posted
Posted

Can you believe I actually tried this in my lounge the other day in an attempt to understand how it all works (clearly guessing polar alignment)

One thing I did find is that when moving the scope around wildly to point at imaginary objects, my eps ended up in wierd positions so I would have had to either stand on ladders or kneel down to look through it... Is it ok to release the tube restraing bands (can't find my instructions telling the correct name for those) and rotate till I can look through without breaking my neck? sorry if that seems obvious but I may be missing something here??? ;)

Link to comment
Share on other sites
Cornelius Varley

Cornelius Varley

Posted
Posted
Can you believe I actually tried this in my lounge the other day in an attempt to understand how it all works (clearly guessing polar alignment)

One thing I did find is that when moving the scope around wildly to point at imaginary objects, my eps ended up in wierd positions so I would have had to either stand on ladders or kneel down to look through it... Is it ok to release the tube restraing bands (can't find my instructions telling the correct name for those) and rotate till I can look through without breaking my neck? sorry if that seems obvious but I may be missing something here??? ;)

That's the way to do it. Loosen the telescope rings a lttle then rotate the telescope until the focuser is in a comfortable postion then retighten.

Peter

Link to comment
Share on other sites
Patbloke

Patbloke

Posted
Posted
That's the way to do it. Loosen the telescope rings a lttle then rotate the telescope until the focuser is in a comfortable postion then retighten.

Peter

Thanks for that... as a total newbie to all this what appears to be obvious is not always so... I can now look forward to my next viewing session knowing that I am doing some of the basics correctly... top place this ;)

I still think there is an opportunity for someone to make a very basic demonstration and stick it on YouTube...

Link to comment
Share on other sites
carastro

carastro

Posted
Posted
by clutches do you simply mean the locking wing nuts that hold the RA & DEC joints in position?
Yes, the locking nuts will release the clutches.
my eps ended up in wierd positions so I would have had to either stand on ladders or kneel down to look through it... Is it ok to release the tube restraing bands (can't find my instructions telling the correct name for those) and rotate till I can look through without breaking my neck?

Sorry, had a chuckle at this as it brought back memories.

Yes, you can rotate the telescope tube (within the mounting rings with a Newtonian telescope for instance). Otherwise with a refractor you can purchase a right angled lens called a diagonal. This gives you a 90 degree angle and it will also rotate in the eypiece. Also will reverse whatever view you already have (I seem to recall).

example:

1.25in. Orion Prism Star Diagonal | Orion Telescopes

Carole

Link to comment
Share on other sites
Cornelius Varley

Cornelius Varley

Posted
Posted
Yes, the locking nuts will release the clutches.

Sorry, had a chuckle at this as it brought back memories.

Yes, you can rotate the telescope tube if possible (with a Newtonian telescope for instance). Otherwise with a refractor you can purchase a right angled lens called a diagonal. This gives you a 90 degree angle and it will also rotate in the eypiece. Also will reverse whatever view you already have (I seem to recall).

example:

1.25in. Orion Prism Star Diagonal | Orion Telescopes

Carole

Diagonals tend not to work with relfector telescopes because there is insufficient inwards focus travel to compensate for the extra distance the diagonal adds to the light path.

Peter

Link to comment
Share on other sites
Calico Jack

Calico Jack

Posted
  • Author
Posted

Thanks Brantuk

Being a beginner, i just coulnt get it. your sentence " tracking in RA only" got me thinking clearer. Although i am waiting for a clear night to try it properly.

After polar aligning, am i correct in thinking that as long as i dont alter the Latitude and Declination , i can unlock the Azimuth and rotate to my desired object ( or lift the entire tripod to my desired object) then RA tracking?

Thanks again Jack

QUOTE=brantuk;1667893]Here's a rough "how to" for observing only:

1. Point the mount north using a standard compass

2. set the altitude scale to the latitiude at your location

3. Line up the main tube with the mount and lock the clutches

4. If lucky you will see the pole star in the finder. If not:

5. Adjust using the latitude bolts and az bolts only untill the pole star is in middle of finder.

6. Adjust further untill the pole star is in the center of eyepiece and finder.

7. Unlock the clutches and move to the desired object and re-lock the clutches.

8. Continue tracking using only the RA control.

Use a 25mm eyepiece for setting up - refine using 10-15mm if needed. Don't move the mount throughout or you'll have to start over.

This won't be accurate enough for photography but will be very useable for observing :)

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.