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Manual Pointing File .... the full process????

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#1 MikePaling



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Posted 26 September 2016 - 04:52 PM

I have just managed to do a fairly accurate initial Polar Alignment without too much trouble .... I now want to move onto a Pointing File.


Looking at the last two versions of the Autoslew manual the explanation of how to carry out a Pointing File manually simply fizzles out :(


The manual suggests that I use the Sequence software and carry out an "Autopoint" proceedure .... but I this software seems to be too advanced for me at the moment and I seem to think that it needs a CCD camera ... which I don't have.

The Autoslew manuals also say that there is information about the Autopoint procedure in the Sequence Manual ... there is absolutely no mention of this in the manual that come with my mount and memory stick!!!


I am happy to do everything manually even if it does take longer.


I am assuming that the process of doing a Pointing file is a more extended version of doing the same that I used for the Polar Alignment .... but with some added bits along the way ... and at the end. For example ... do I have to set a "New Home Position" at the very end of the procedure???? The manual doesn't say.


So ... could some kind person give me a step-by-step checklist of what is needed before I take the plunge?


Any help would be very much appreciated.


Regards Mike


#2 GeorgeCarey



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Posted 26 September 2016 - 06:06 PM

The pointing file is similar to the polar alignment except that there are more stars and you use both hemispheres.
It is many years since I did a manual file so my memory is weak.
I think it goes something like:
Clear old configuration.
Tell Autoslew you are making a pointing file.
Find first star and sync on that star.
Autoslew prompts to sync...ignore.
Move to next star, centre it and confirm.
Keep going - try only 5 stars in each hemisphere till you are confident.
When you have done your stars stop and calculate configuration.
Click on 'use now and save for next time'.

Now try and use the file by slewing to a star. It may be a bit off so centre it and sync on it.
Set a new Homeposition - most important.
Also Save parameters before you shut down Autoslew.

ASA DDM60Pro, homemade 8" and 10" reflectors, QSI 683 camera, Astrodon 5nm filters, Pulsar dome observatory. Website: http://www.geoastro.co.uk

#3 RamaSpaceShip



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Posted 26 September 2016 - 06:40 PM

Hi Mike,


To do a pointing file manually, you need to:

- choose a starting star, center it in your eyepiece, and sync on it

- click "start pointing file" in the menu. Don't care about the message asking you to sync first, as it's already done

- Name your pointing file

- use the currently pointed star as the first star, slew to it (should do nothing) and click the ticked target button in the menu bar

- then choose another star on the same side of the meridian

- slew to it, center it, and click the ticked target button in the menu bar

- check the error values in the bottom line of Autoslew, if they are too big, discard the star by clicking the "delete last star" button in the pointing file submenu

- repeat the last three steps with as may stars you want on this side

- then choose stars on  the other side of the meridian

- take care that the errors in this case may be big, and you probably should not discard the star in this case (I don't know as I never use the other side)

- once you have finished, click "Stop pointing file" in the pointing file submenu

- then click the "Calculate configuration" button in the pointing file submenu

- you will get a window where you choose  "Use now, save and use on next start"

- then choose a star near zenith, sleew to it, center it, sync on it

- and click "set new home position"

You're done.


(I wrote this from memory, so I may have forgotten some step, but some other experienced user will hopefully fix it).



Best regards.



Edited by RamaSpaceShip, 26 September 2016 - 06:42 PM.

#4 MikePaling



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Posted 26 September 2016 - 10:08 PM

Many thanks George and Bernard for these pointers ... it was mainly the first and last steps that I was not 100% sure of.


On Wednesday I will be away for two weeks ... but rest assured I will be doing my first Pointing File on the first clear sky when I get back :D



#5 DaveS



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Posted 28 September 2016 - 06:33 PM

I have found it's useful to do in intermediate configuration to allow for any collimation error. I found that if I didn't then after meridian flip I could be miles out, but if I did an intermediate configuration I would land near the centre of the sensor.

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