I'd thoroughly recommend the link Gary put in. The drift alignment simulator is brilliant. To be able to sit at your computer and practice and to see the results in real time is great. Better than trial and erroring it out under the stars when all you want to do is image.
You have a GEM mount so the telescope tube will be pointing south and pointed up at the angle you have your latitude set at. That is, in our case, - 90 degrees declination, forget about RA for the moment. If you look at the Declination circle it should say 90 degrees, in other words it is pointing at the SCP, now, if you move the tube so it is at 90 degrees to the Polar Axis it will be pointing at 0 degrees on the Declination Scale. Now move the telescope in RA, it will scribe a circle, that is the Celestial Equator or, 0 degrees declination. If you leave the counterweight down and have the telescope at 90 degrees to the polar axis, or 0 degrees declination, it will be pointing either due west or due east depending on what side you pointing.
But i do as Alex dose and photograph through a long postal tube attached to the polar shaft of my camera drive with a 50mm lens at infinity, and expose for half hour, no tracking.
and you get circles around the SCP, you cant get any closer than that.
They say a picture tells the story, have a look at this shot of my setup, you will see on the DEC axis is is set close to 90 degrees and it is pointing at the SCP.
Matt and all frienss,
Below is what I found out suit me and all of us (I believed) and please let me know or give any comments whether I am right or not.
Step 1.
Point the mount and the scope to the SCP roughly.
Step 2.
Stand behind your scope and slew the RA to East (Anticlockwise from your eyes) so that the scope is at horizontal position.
Step 3.
slew the DA 90 degree to the North and that is my starting point.
Step 4.
align the illuminated ep so that when you move the RA, the monitoring star is within the red lines.
Step 5.
Center that star and wait for a while (if the initial polar align was good then you have to wait for a longer time) and you know how the star drift. At this stage, don't bother where it drifted, the drift S or N doesn't matter at all.
Step 6.
Adjust the Slew speed to 2, then slew the DA to the north a little bit and check the star drift.
Step 7.
If the star drift further, then you mount is set too far to the west then adjust the mount to the East of course and start step 5 again. If in the opposite case, then your scope is too far to the East.
After several iterations (4 in my case last week with more than 10 degree away), you got there and you can start the next step.
Step 8.
Point your scope to the SCP again.
Step 9.
Slew the RA 90 degree to the East and find whatever star you can, or adjust the RA until you find one if the visal was blocked.
Step 10.
Adjust the illuminated ep so that when you move the RA, the monitoring star is within the red line.
Step 11.
Center the star and wait for a while.
Step 12.
Check the drift, adjust the declaination of the mount so that star return to the within the red lines and start step 11 again.
The above procedures can ignore any configuration of the scope such as with or without the diagonal or polar scope and ignore whether the star drift to the N or S.
Bill
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