Polarscope Optical alignment on AZ-EQ6-GT

[todd8137]

Mine does this on my cgem mount I to some times use alignmaster

Pat

[wxsatuser]

Wxsatuaer - is yours now the same as mine? When the weight bar is pointing left, the cross hairs are directly over the target, when the weight bar is pointing right (after a 180 degree turn) the cross hairs are still directly over the same target, but when it is rotating between the two, the cross hairs drift off the target?

Jd

Yes.

[neil groves]

thing with align master is you need to hook the mount to a laptop?

Neil.

[Mark_C]

Just had a quick play with the QHY5L-II and it seems I don't really get fantastic PA when using my polar scope, I get star trailing with just a 30 sec exposure. I use EQMOD to position the reticule precisely so it's as good as it's going to get. Perhaps I'm expecting too much for just polar scope alignment?

thing with align master is you need to hook the mount to a laptop?

Neil.

Yes a laptop is required for Alignmaster. You could always use the built in polar align feature of the Synscan handset, I believe this works in a similar fashion to Alignmaster, although the latter may perhaps offer a more accurate PA. I will have to give it a try myself when the weather behaves.

[neil groves]

question answered elsewhere.

Neil.

[PatrickGilliland]

mine does it too but i only use the polar scope for rough alignment and then use alignmaster

As a newbie too Alignmaster is a dream to use.  Would recommend it to any newbies and removes one issue from the set up process and to be honest I think when the alignment process is repeated a few times it is more accurate than the polar scope method.

[jambouk]

The handset routine is easy to use and doesn't need a laptop for anyone who doesn't want to involve a laptop.

Jd

[Mark_C]

The handset routine is easy to use and doesn't need a laptop for anyone who doesn't want to involve a laptop.

Jd

Is there any particular routine that should be followed to allow better alignment using the handset? I've noticed some people have had bad luck using the 3 star alignment and the PA feature.... I've still yet to try it but if there is any way I could increase my chances of a more accurate PA without too much fiddling around, that would be a great help.

[jambouk]

Yes, if you have the latest version of the firmware on the handset (3.35 I think), there is a Polar Alignment routine which gives you a pretty good polar alignment after a few runs.

Roughly polar align as normal using the polar scope or just pointint it north, whatever you do.

Do a two star alignment, say Arcturus and Vega (ideally use a cross hair reticle eye piece if you have one)

Then do the polar alignment routine

 - It will ask you to go to a star, pick Arcturus or Vega again, then re-centre it (ideally with the cross hairs of a reticle eye piece)

 - It will then tell you the error, and slew the scope away from the star.

 - It will tell you to adjust either the azimuth or elevation knobs (elevation is always first with my set up and you only make adjustments with one knob at a time)

 - Use the elevation knob to move the star back as near the cetre of the FoV as possible (don't use the handset); It may not go to the centre, just get it as close as possible.

 - Then accept it and it will then slew at right angles and ask you to re-centre the star using just the other knob (eg azimuth); again you are unlikely to be able to actually get it in the cetnre, just get it close as possible

 - Then once accepted the position, the handset will say what the error now is (this is false)

 - Do a new two star alignment, picking the same stars, and then once you've done this it will tell you the correct error in Mel and Maz

 - You can opt to then do another polar alignment routine, and repeat the above. Always do a two star alignment at the end to work out the true error in elevation and azimuth.

I find three cycles of the above (which takes 5-10 mins) gets the Mel and Maz to under 1 arcminute in error.

JD

[Ouroboros]

Just for interest, after you've done that have you looked up the polar scope to see how far polaris has moved relative to where you put it in the first place?

[jambouk]

I've not, but the polaris circle will be in a different place as the RA axis will have been rotated, but one could look to see how far off the big circle polaris was for sure. I've just not bothered. I will look next time if i remember.

Jd

[Ouroboros]

OK :-) I can try too next time I get out there. I've not yet tried using the handset to improve polar alignment after the initial alignment.

My experience has been that the initial polar align, plus 2 or 3 star alignment, is fine for visual observing. Combine this initial set up with guiding and it's good for AP too. But then I've really only had the chance to do some test astrophotography runs rather than real ones if you see what I mean. The skies and opportunities for astronomy have been dreadful for the past 6 months.

[jambouk]

I'm not guided so PA is more important for me unless you are doing a very bad PA or longer guided exposures.