Attention DRIFT aligners

[Sgtfretsurfer]

hey im new to drift aligning and i cant seem to get my head around something. if im using a Newtonian telescope and adjusting the azimuth (ie with star on the meridian above the SCP) and i noticed that the guide star drifts in an upwards (northerly) direction, does the azimuth need to be adjusted towards to the west or the east? also is the 'upwards' direction governed by the movement from the RA axis?
i have found a few guides on the internet but most are for the northern hemisphere (so im supposed to reverse it?), and one site mentioned that u have to reverse everything for a Newtonian telescope. trying to get my head around it is sending me mad!

[Geoff45]

First identify the directions in your eyepiece. Start with the west (Preceeding) direction. This is the way the star drifts in RA when you are not running the motor. Directly opposite to this is the east (Following) direction. Then for a Newtonian with no eyepiece diagonal, you can identify North and South by going around the edge of your field of view a circle in a clockwise direction PSFN -- Preceeding, South, Following, North--easily remembered as "Poisonous Snakes Fear Nobody". If you do use an eyepiece diagonal, you have to go counterclockwise. (More precisely; if your optical setup has an even number of reflections, go clockwise. If it has an odd number of reflections--eg a refractor with a diagonal-- go counterclockwise)

If you look East to adjust altitude, then if the star drifts North, raise your altitude, if it drifts South, drop the altitude.

If you look West to adjust altitude, then if the star drifts South, raise your altitude, if it drifts North, drop the altitude.

Now pick a star on the meridian near the equator. If the star drifts North, turn the mount clockwise as viewed from above. If it drifts South, turn the mount counterclockwise as viewed from above.

Repeat these adjustments until you get no drift when you swap from one to the other.
Geoff

[Sgtfretsurfer]

thanks mate, ill try that out tonight once/if these cursored clouds clear

[iceman]

Excellent explanations, Geoff. I'll have to translate that into my home setup but very clear and easy to follow.

Thanks heaps!

[xelasnave]

Geoff I must agree with Mike.
I have read so many "tips" on what to do and as with many things the attempts of authors to explain the matter fully sees an un necessary complexity confusing the reader... and when one is cold tired and frustrated trying to align needs to be simple. I intend printing out your words and pasting them on my pier mount;) . Make up a brass plate even:thumbsup:
Excellent explanation that should remove the fear of the proceedure for the novice.
alex:) :) :)

[rogerg]

This might help.

http://www.rogergroom.com/rogergroom/esh_rog_item.jsp?Item=27

[Satchmo]

THis polar alignment simulator is a great way to practise the drift alignment from the comfort of home :)

Click the top left button on th epolar scope at right to see how close you get to the South Celestial Pole.

http://www.petesastrophotography.com/tutorial/guidingsim.html

[LX200]

G'day Mark
That was a great simulation! :thumbsup:

[Lee]

Its hard - all the explanations on the web didn't finally get it for me - certainly helped start the process - what taught me was to sit outside for hours, and write down exactly what you did - what knobs move which direction etc....

I found switching off the RA drive handy - then watch stars drift west, then you know which way west is for starters.....

[xelasnave]

What gets me is the times you can do it and there are no problems and then absolute confusion. Is it just me?
I know purists score this suggestion but I find when all else fails to point the scope so as to be parrallel with the RA and take a time exposure..check the results and move the mount to get the circle of star trails in the center of the next shot.. then add a barlow and do it again. This would be a perfect method if the scope is exactly parrallel to the RA and I am never sure how parrallel it is.
alex

[Geoff45]

Instaed of trying to remember a whole bunch of meaningless rules, you need to think about what is going on. I look at the way the star drifts (N or S), hold up my left arm to the sky to model the motion of the star and my right arm to model the motion of the scope that makes the star drift the way it does, then think about what I have to do to the mount to make my arms coincide. It's really a nobrainer.
Geoff

[xelasnave]

Thats the best advice yet Geoff..like a big set of dividers..mmm now I see an accessory opportunity there...
alex