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INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

Problem with polar alignment in southern hemisphere?

1 month 2 weeks ago
xthestreams
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Problem with polar alignment in southern hemisphere? #52301
I too am having the same problem and arrived at the same solution - do the exact opposite of what the tool is telling me!
To your questions;
1. aligned with finder scope (upper left hand of primary, only roughly aligned) - ZWO290MM mini camera mounted upside down in the refractor (to orient the image in teh right way visually)
2. My mount rotates in the specified direction - always west ( I can try east if that helps) (that is weights rise to the east, OTA sinks into the west)
3. No matter what I did with the mount Ekos always reports "mount is oriented to the top left of the celestial pole" (or similar language) - that strikes me as odd
4. Please NO! ;-)

When I was trying to diagnose the problem I thought it was strange that the tool indicated the the celestial pole was not visible in the FOV but when I looked at where the mount had solved to in the kstars planetarium it looked it a). it WAS in the FOV and b). the orientation of the sensor as indicated didn't seem to match what I saw in the eyepiece (inverted)

So I am thinking a bug in the WCS/solver when close to the pole and/or the FOV crossing the meridian?

Meade LX90 OTA
Meade LX90 mount - on a wedge, slightly dead (bloody Dec motor driver board blown)
SkyWatcher NEQ6R Pro mount (oh my goodness the difference!)
ZWO ASI 183MC Pro camera
Svbony 270/60mm finder/guide scope
ZWO ASI290MM mini guider
ZWO ASI224MC all-sky
more toys to come....

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1 month 2 weeks ago
wildi
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Problem with polar alignment in southern hemisphere? #52326
Hello xthestreams

So I am thinking a bug in the WCS/solver when close to the pole and/or the FOV crossing the meridian?


I noticed that astrometry.net has difficulties once the center of the image is close to CP. That's natural. Let's assume we have a resolution in declination of 1 arcsec/pixel. In RA direction the resolution is the same at the equator but the closer to the CP the resolution increases unbounded e.g. 10 degree/pixel. The pixel "on" the CP has no defined resolution.

I suggest to separate this aspect, do the alignment at dec = 80 deg and repeat it several times. Of course, the idea is only to see if the results are reproducible, but surely not use them to correct the alignment.

Kind regards, bye, wildi
The following user(s) said Thank You yoandresmza, xthestreams

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1 month 2 weeks ago
xthestreams
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Problem with polar alignment in southern hemisphere? #52392
Great idea, will try when Melbourne isn’t cloudy at night, expect a reply in 2021 ;-)

In all seriousnessFriday should be good for testing, if there are other ideas I’ll add them to my list.

Now to figure out why you Mac k stars crashes/loses connectivity to my RPi sleeps

Meade LX90 OTA
Meade LX90 mount - on a wedge, slightly dead (bloody Dec motor driver board blown)
SkyWatcher NEQ6R Pro mount (oh my goodness the difference!)
ZWO ASI 183MC Pro camera
Svbony 270/60mm finder/guide scope
ZWO ASI290MM mini guider
ZWO ASI224MC all-sky
more toys to come....

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1 month 2 weeks ago
wvreeven
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Problem with polar alignment in southern hemisphere? #52395
There is a calculation done in KStars for the direction in which the pink arrow should point and this sometimes gives the wrong result. It is unclear why. As a workaround Jasem has implemented a checkbox that allows you to reverse the direction of the arrow in case the polar alignment is affected by the calculation. Unfortunately, this workaround is not available yet in the stable release of KStars. Until such is the case, you’ll simply need to remember to make sure that the END of the pink arrow is over the star that you’ll be using to improve the polar alignment rather than the START.


HTH, Wouter

ASI1600MM-Pro Cooled and filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
The following user(s) said Thank You xthestreams

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1 month 2 weeks ago 1 month 2 weeks ago by xthestreams.
xthestreams
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Problem with polar alignment in southern hemisphere? #52396
Thanks Wouter - just to add for anyone who is having this problem, if you are WAY off on your initial alignment you may not be able to see the little red "cross hair" that is mentioned in the instructions (the fact that there is also a purple set of cross hairs may even add to your confusion given the bug - as it did for me).

If this is the case, then you should use the purple cross hairs as a proxy for the red one you will se as you get closer to PA, what you need to do is;
1). do your three alignment photos as per the standard alignment process
2). when the results are computed you will see a PA error in degree/minutes/seconds - the SCALAR for this is accurate, the VECTOR is not (ie: the size of the error is correct, it's just telling you the wrong direction) - you will need to do the opposite of what is said on the instructions with regards to the pink line.
3). To help you guide, I recommend you position the cursor with the pink target finder/cross hairs somewhere on the screen as though there is an imaginary line that continues from the end of the pink line all the way down as far as you can go on your screen - for this reason it's usually best to double click somewhere on teh results screen to move the end of the pink line to create as much space as possible to create your "virtual line" (it will make more sense with screen shots i am sure - PM me if you need help).
IGNORE ANY INSTRUCTIONS ABOUT SELECTING A BRIGHT STAR, you will use your pink target icon to make your own virtual star
4). once you've done this (moved the pink line) click next and start refreshing as per the instructions - now move your mouse pointer over the results screens (where you can see the star field) and place BUT DO NOT CLICK) so that the pointer/target icon is floating on an imaginary vector that joins the tip of the pink line in one continuous line to wherever you place the pointer/target icon - this becomes your "virtual star"
5). now adjust your RA and DEC to get the tip of the pink line to move towards your "target" virtual star - remember we are doing this just so we can get the scope closer to the SCP/NCP so that we can see the little red target that Wouter mentions.
6). then follow Wouters inductions as above, the hardest part will be remembering to do the exact opposite and then of course to line up your star with the very end of the TINY little pink line, but it is possible to get within a few arc seconds with a little practice.
7). wait for the fix/workaround :-)

Meade LX90 OTA
Meade LX90 mount - on a wedge, slightly dead (bloody Dec motor driver board blown)
SkyWatcher NEQ6R Pro mount (oh my goodness the difference!)
ZWO ASI 183MC Pro camera
Svbony 270/60mm finder/guide scope
ZWO ASI290MM mini guider
ZWO ASI224MC all-sky
more toys to come....
The following user(s) said Thank You knro

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