Alignment

[groberts]

I came across this alignment method on the Forum but can't fathom out:

http://www.cloudynights.com/page/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760

1. It seems to be saying that the star for alignment needs to be on the horizon - is this so + as I don't have an horizon (trees and houses in the way) does it invalidate the method?

2. My up-to-date (2014) Synscan controller does not have a W (West) button, is this function somewhere elsewhere deep in the menu?

If this cannot be used for polar alignment, is there another simple /idiot proof method that will get good results, I am finding most of the instructions in Syscan and other mehtods quite baffling.  NB my house is in the way of Polaris so can't use the polar scope either!

[ronin]

I personally would not go for "horizon", at least not as in flat, perhaps at 25 or 30 degrees and above.

My reason is simple, don't trust the horizon.

When the sun sets we see it go down, however owing to refraction when the "lowest" bit of the sun touches the horizon the sun has actually fully set below the horizon. So "on the horizon" isn't on it, it's below it.

Would seem to mean that picking anything on the horizon is questionable. From something somewhere I seem to have the idea that an object on the horizon is either 3 or 6 degrees below.

Not sure what you mean by  a W(est) button?

[groberts]

Nor do I - item (9) on the accompanying link says "press the W on the telescope keypad"? 

[bruno]

I'd of thought that the west button is the left hand arrow button as you look at the hand set

[Owmuchonomy]

I came across this alignment method on the Forum but can't fathom out:

http://www.cloudynights.com/page/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760

1. It seems to be saying that the star for alignment needs to be on the horizon - is this so + as I don't have an horizon (trees and houses in the way) does it invalidate the method?

2. My up-to-date (2014) Synscan controller does not have a W (West) button, is this function somewhere elsewhere deep in the menu?

If this cannot be used for polar alignment, is there another simple /idiot proof method that will get good results, I am finding most of the instructions in Syscan and other mehtods quite baffling.  NB my house is in the way of Polaris so can't use the polar scope either!

Is there a reason you can't use the Polar Alignment routine in the Synscan software? It's quite ok once you get used to it. You need a good idea of where Polaris is but you don't actually need to see it. I don't need to do an additional drift align so I'm not familiar with the method you linked to but common sense would tell me that a star on the celestial equator would be most appropriate which at my latitude is 36 deg above the S horizon.

[groberts]

No, I am pursuing the Syscan polar alignment too but struggling so was also considering the other method.  Figured that as my next step after x2 star alignment is usually to focus on a star using a Bahtinov through the camera & computer, it would be just as easy to run through the polar alignment this way too, and possibly more accurate?  

[groberts]

Last night for the first time I tried using the Synscan Polar Alignment function, with some difficulty.

I understand the principal and tried to follow the Manual (Section 11.3) to the letter but when it got to point-6 the Synscan instructions, after finding, centering a star and pressing Enter, it did not correspond to the manual's guidance.  The Manual says -  "The  mount will slew to a new position.  When it stops, the screen will display 'Adjust Altitude'. By using only the altitude control bring the reference star back to the closest point to the centre of the FOV.....".  And then points 7 & 8 outline a similar procedure for the azimuth.  However, instead of moving to two separate adjustment procedure for the altitude and azimuth, at this point the Synscan handset said something like - adjust the altitude and azimuth using the azimuth knobs and altitude T-bar - which I did and after which pressed entered which took me back to  the start of the Polar Alignment procedure again.

Am I doing something wrong or, I wonder, has the procedure changed?  This is a new AZ-EQ6 GT mount with (I think) V3.3.3 firmware and perhaps Synscan has been changed.

Whilst I would still like to crack this procedure I wonder if there is an better / easier, idiot proof way?  

[groberts]

Practice and perseverance = progress!  

Another clear sky last night, so I started early and again tried to carry out the Polar Alignment routine using Synscan.  This time I ignored the manual and followed the handset instructions, which as I have said, after the two star alignment and subsequent Polar star alignment asks to use the altitude and azimuth T-bar and knobs to realign the star manually.  Also, aware that this is an iterative process and more alignments equals better accuracy, I went though the star alignment and Polar Alignment a second time.  The result was superb, for the first time the MEL and MAZ error was negligible and the GOTO function and tracking worked like a treat, straight to each chosen object which was always on or very close to centre.  It is now clear that Synscan V 3.33 and the manual are not the same, be warned.    

A bit more practice and I'll be ready to move on to my next challenge, auto guiding.  In the meantime, thanks for comments - I would still like to find another, more slick polar alignment method if possible but, for the moment, I am very pleased.

As a matter of interest with good basic alignment, such as this, what sort of camera exposure time would be reasonable to expect whilst tracking? Furthermore, with this and basic autoguiding (i.e without PEC etc) what sort of tracking exposure should that give?           

[Owmuchonomy]

Excellent. as I said it is quite straightforward. I get 90 seconds with my HEQ5 pro at FL 715mm unguided.

[Phillyo]

Using a normal EQ6 with EQmod at 348mm FL I managed 10min subs. It depends on your mount I think. Only way to find out is to test it and see

Good luck.