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Polar alignment problems. Picking new alignment group? #ExploreStars

 
Edited

Due to the location of my backyard I can barely see Polaris and the rest of the Alignment Group 6. Is there a way to align using other stars? Such as Rigel? I can only see group 6 under my 2 or 3 star alignments. My house and the neighbors block that portion of the sky but if I move to see them, I can only use the sky that is illuminated by street lights. 

First time using the mount and I was able to get pretty tight stars at 30 sec, so that's working well! I still suuuuuuck at slewing manually to find anything. Took me forever just to center a single star.

Chris Tardif
 

Hey Burks....I'm not sure what your rig is so I will generalize a bit...

If you are using a scope and not a camera lens then I found using an eyepiece to star align really helpful, but software can help.

I use a PC, Windows and ASCOM so I use SharpCap for polar align (which can do a drift align so you don't need polaris) and I use All Sky Plate Solver to center images.  With this set up you can get away with some error in you PA depending on how short or long the focal length you're using its.  

Make sure its dead level and use a compass to point it north before you put the mount on. That will get you 90% of PA then you should be able to get the rest with software.

HTH....

Chris



--
Mounts: Explore Scientific IEXOS-100 w Celestron CG5 tripod, iOptron CEM 40
Scopes: Explore Scientific FCD-100 ED-102CF, Various Canon lenses, ZWO mini-guidescope, StarField 60mm guide-scope.
CameraASI120MM Mini (mono), Altair GPCAM 130
Control PC: Intel NUC
Loc: 44 -79

W.F.
 

Hello Burks,
when you start the alignment, the sytem shows you a star and moves the teleskop on it.
If you now go to the main menu ---> catalog, it shows you stars for alignment.
There you can select the star you like to use or you can see.
Click at the Icon an then "slew to the target", in the main screen you can see the star is now in your alignment.
Now follow the steps as usual.
Greetings Wolfgang.

 

I'm sorry Chris, I bet that info would be helpful. It's an iexos-100 mount and I'm using the Explorestars app on my laptop. 

Wes Mcdonald
 

Burks21

What tablet?  Each version works a bit differently during alignment

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired

 

Wes, 

Not using a tablet. Sadly my wife's Kindle Fire and ipad 2 are too old. So I'm stuck with my laptop. 

W.F.,

Problem is the group assigned to my alignment really arent useful for me due to houses blocking that part of the sky. I basically can see from the direct north (barely) to the south. Anything west is a no go. 

Wes Mcdonald
 

Burks

The windows explorestars could use a facelift.  I suggest you get an Android based system.  Its alignment routine allows you to select stars from the catalog.  This is a capability peculiar to the Android version.  It also gives you the ability to select a star prior to slewing to it.  This saves time and circumvents a minor issue that can lead to the mount moving very slowly during a slew.

You can get an inexpensive Samsung tab A which I and others have had.   The fire hd also seems to work.  Don't go Chromebook however.

You can also use an iterative method for polar alignment as detailed in a paper Jerry posted.  The routine calls for using Polaris and one other star but I believe you can use any other star instead.  This is a method that can get you both polar aligned and get your ra and Dec home positions correct so that further gotos will work.  If you do this, you have no need for the 2 or 3 star alignment.

In my view it is impossible to perform the 2 or 3 star alignment without a red Dot finder.  Get one. It's about the only way you can decide which star is the proper alignment star.  I also use SkySafari to identify the exact star in the star field which I then center in the red Dot and then in the eyepiece.  

When you do the centering you must get it very close to eyepiece center.  Error in centering will be reflected in the alignment solution and make your gotos worse.

Finally it is very important to get your ra and Dec home positions correct.  I posted a procedure and discussion document in the files section of main or mounts subgroup.  Use the second section for astro photography as it is the only way to get those home positions... Short of using cameras.

Wes

--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired

Chris Tardif
 

If you're using a laptop then I go back to my first post.  Free software can save you.  AstroPhotographyTool (APT), All Sky Play Solver and SharpCap.


--
Mounts: Explore Scientific IEXOS-100 w Celestron CG5 tripod, iOptron CEM 40
Scopes: Explore Scientific FCD-100 ED-102CF, Various Canon lenses, ZWO mini-guidescope, StarField 60mm guide-scope.
CameraASI120MM Mini (mono), Altair GPCAM 130
Control PC: Intel NUC
Loc: 44 -79

 
Edited

Chris,

I am using a laptop for right now, but I have downloaded APT just to try it out anyways. I'll be getting an Amazon Fire 8HD during the black Friday sales.

Wes,

I'm hoping with the combo of APT, a compass, and some better knowledge I will be able to get a better polar alignment. I am also waiting on black Friday sales to maybe pickup a guide scope and adapt my webcam (I've used it to take some pretty decent video of the moon) so that I can use that to help guide/alignment issues. I might grab one of those illuminated crosshair eyepieces if I continue to have trouble, but I'll wait as those seem to have only one job and one job only. I wouldn't mind being able to polar align and guide with the same setup. Maybe, if they are on sale, I might even grab a 120MM camera to use as a guide camera (or even imaging?) as well. Who knows. Just got a really nice bonus from work so....that helps!