please confirm if this is correct

[leon]

Hi All,

Although i know how to drift align, i have had some confusion over the up and down, and east, and west bit.

Because, when i was doing mine last night, i was actually turning it in the opposite direction than suggested by some, but it was working, and got the eastern horizon one pretty right so far.

So Is this correct please.

Eastern Horizon

If it drifts sth, or down, raise the eq head
If it drifts nth, or up, lower the eq head.

Meridian

If it drifts sth, or down, turn the axis to the west
If it drifts nth, or up, turn the axis to the east.

Please could someone confirm this procedure.

Thanks Leon

[Astroman (Andrew Wall)]

If thats right then I have been doing it the wrong way. No wonder my drift aligning isn't working. I thought it was:

Eastern Horizon move left or right..

Meridian

move up or down.


I have a funny feeling you may be right though Leon.

[leon]

Andrew, i know that the eastren horizon is up or down, or is it down or up, that is what i'm trying to find out.

And i know the meridian is left or right, or is that right or left.

Just need confirmation for the right directions

Cheers Leon

[ballaratdragons (Ken)]

As far as I understand it, you drift the star in the same orientation on both East and south.

[DavidH]

Originally Posted by leon

Hi All,

Eastern Horizon

If it drifts sth, or down, raise the eq head
If it drifts nth, or up, lower the eq head.

Meridian

If it drifts sth, or down, turn the axis to the west
If it drifts nth, or up, turn the axis to the east.

These directions are incorrect, in absolute terms.

If, at the eastern horizon, the star drifts south, then the mount is moving north too much, meaning that the axis is pointing too high, and needs to be moved down(I need a diagram here).

At the meridian, if the star drifts south, then the mount is again moving too far north, meaning that the axis is too far west, and needs to be moved east.

Have a good look at your mount in the daylight and check that moving the knobs works as you expect. I spent a good few hours in the dark with an erroneous idea of how my mount worked, trying to figure out why I could not get it aligned. Also take account of any optical 'flips' in your light path.

I also found that writing down a set of instructions for myself and testing these under the night sky kept things clearer in my bamboozled mind.

Regards,
David.

[xelasnave]

David you are so right about having some notes it is supprising how you can get so mixed up at times...and others a little less
alex

[leon]

Thanks David for the info, i will write this all down and study it, when looking through the EP. it can get confusing, especially for a novice like me.

However, by saying that it moves south or north, is this the same as down or up, or is the movement actually regarded as Nt and Sth.

By this i mean, if i were looking in the Reticle and the star moved in a downward direction, out the bottom of the reticle square, i would call this a northern direction, as it would be heading toward the lower end of the polar shaft which is pointed nth, and if it went out the top of the reticle, this would be a southern direction, as it would be heading toward the top end of the polar shaft which is facing the SCP.

Gee, now i have really confused myself, but would this be correct.

Thank You

Leon

[DavidH]

Yes, confusion reigns.

I try to think in absolute terms (i.e. north and south) .

Up, down, left and right are relative to the viewer and telescope combination, so I think it is best to avoid these terms if possible.

I have a reticle eyepiece which has a double crosshair (I think most do, but mine is the only one I have seen). I line up one direction of the crosshairs with the RA axis of the scope (it does not really matter if the scope is only roughly aligned at this stage). By pushing the scope south, I can see which direction a star will go in the eyepiece if it drifts north.

In my instructions, I ended up with two 'through the eyepiece' diagrams, showing whether to tighten or loosen the altitude and azimuth adjustment knobs, depending on the drift direction of the star.

HTH.

Regards,
David.

[adlsa5092]

Hey Leon,
"North, south, east and west, may God bless the bed on which I rest." just about sums up all the palaver about which way to adjust your scope!

Try this, it's simple and you really don't have to sweat ....

1. point your scope East as low to the horizon as you can get and pick a star you can see
2. centre the star in your FOV, say 12mm eyepiece
3. look for up or down drift; adjust your altitude -slowly - to bring star back to the centre horizontal line in FOV (imaginary if you don't have cross hairs)
4. keep doing 3 until the drift is minimal, say 5' over 15 minutes in time
5. find a star directly overhead close to the meridian and centre it
6. again, look for up or down drift - adjust your mounting horizontally (CW or CCW) - slowly - to bring star back to that horizontal centre line in FOV
7. keep doing 6 as for results in 4

You might have to do the above a couple of times and if you're using a diagonal, have the eyepiece pointing up to 12 o'clock relative to the OTA.

Unless you're an absolute purist, this will get you there - good enough to to do imaging up to a few minutes per shot.
cheers

[leon]

Thank you for your response to my request, i'm sure i will get it together.

Leon