2/3 Star Alignment, possible to select the stars to align? #ExploreStars #alignment


Euan Milne
 

Folks

I am using ExploreStars on Windows10, From my back garden i have a limited are of sky to view (also the bright nights does not help) I can easily identify Vega and Arcturus and would like to do a star alignment on those but I am unsure of how to make ExploreStars select those two for alignment purposes.

Also when alignment is complete is a message or an indicator shown on screen?


--
Mounts: ES PMC-8 IEXOS-100
Scopes: TAL-1
Cameras:  Canon 1200D, Canon 70-210mm,  Tamron 150-600mm, 50mm prime. 
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver


Wes Mcdonald
 

Euan

The short answer to your question is no.  You just have to keep going to the next star until the windows app picks the one you want.  The iPad app also works in this manner.

The Android Explorestars app however lets you pick your alignment stars.  You start the alignment process and go to the catalog menu from which the target star may be selected.   

If you decide to use the Android app and get a tablet running Android 10 or newer be sure to load the app from the link on the Explore Scientific web site, as the one on the play store does not support the newer OS version.   It would be best probably to buy a used tablet with an older version of Android on it.  

You can research other means for doing polar alignment on the internet.  Drift alignment is an example of such, and starting from a rough polar alignment given by PSALIGN it should be pretty quick once you get the hang of it.   This will give you a good physical polar alignment, after which there is no need for a 2/3 star virtual one.

The Android and iPad apps are superior to the windows app, as various features have been added that aid in use.  One of the main features is these apps allow you to prevent the mount from taking off to the next alignment star or any target for that matter until you press the goto button.   Thus when you are cycling through alignment stars looking for one you have visibility for the mount will not be doing crazy slews all over the place.   

Be aware that the 2-3 star alignment only creates a virtual alignment.  This means that while the thing can find objects it is not necessarily polar aligned.   The software continuously computes the required ra and dec motor position (5x per second) and moves the mount continuously.  This will lead to a bit of jitter in your images and might also cause the objects to rotate in the field of view during a timed exposure.   This occurs when the triangular mode indicator shows the letter P for point mode.   When the indicator shows T for track mode the mount ra motor runs smoothly at sidereal rate while the dec motor is stopped.   This is what is needed for the best astrophotography, however for imaging purposes the mount will need to be mechanically polar aligned.   This is where drift alignment or some other method comes in for you.  

In the windows app I believe the mount, after a goto slew, is put into the P mode.  To get it into T mode you must press one of the left/right/up/down buttons.  You can set the rate to 1 and bump one of the buttons and you will be in T mode.   Doing a goto again to the same target will put you back into P mode.  I think.   I don’t use windows Explorestars anymore and might be wrong but the gist is correct.

In both the Android and iPad apps the triangular indicator is also a button which can be pressed to easily transition the mode back and forth between P and T.  This is another reason they are superior, in my view.

You probably should connect up your mount via the serial connection and find out what version of code you are running.  You can do this from the Configuration Manager program available from the Explore Scientific web page.  Use it to send the ESGv! Command.  If you are not running the latest firmware in the mount I suggest you upgrade using the install kit and following the included instructions found therein.  The kit is available from a link on the explore scientific web page.  All you need is a proper usb cable and (very important) a usb-to-serial converter driver installed on the windows box.  Suggest you load the one that can be found on the parallax web site.   It works well.  Your version should be 20A01.02 or higher (.03,.04, etc).  I would be very interested in knowing which your mount came with, especially if you bought it new.  The older versions for the iexos were something like 1Axxxxx. 

Regards
Wes





--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Cesar Brollo
 

Hi Euan, You can choose the stars alignments from the catalog while you are making this, the interesting thing is that going to the same option do you have a aligment star catalog (only before finish the alignment)  that show all possible bright stars in order of declination ( a A-Z order and a search option could  be more helpfull) and you can select any star from  this screen (actually when you return to get a 2nd or 3dr  star you can read that this, the order of star, is shown on screen) . When You have ready the alignment, and return to catalog, do you have the Main Catalogue, with pictures, searcher, etc.



El sáb, 17 jul 2021 a las 6:48, Euan Milne (<euan_milne@...>) escribió:
Folks

I am using ExploreStars on Windows10, From my back garden i have a limited are of sky to view (also the bright nights does not help) I can easily identify Vega and Arcturus and would like to do a star alignment on those but I am unsure of how to make ExploreStars select those two for alignment purposes.

Also when alignment is complete is a message or an indicator shown on screen?


--
Mounts: ES PMC-8 IEXOS-100
Scopes: TAL-1
Cameras:  Canon 1200D, Canon 70-210mm,  Tamron 150-600mm, 50mm prime. 
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver


brian skinner
 

Euan, in addition to Wes, on the android app in order to manually select your alignment stars from the catalogue you need to set auto align off on the settings page.....
--
Brian Skinner
iEXOS100
Canon 1300d dslr
Various lenses
ES Polar scope
Sequator image stacker
PIXR image editor


Euan Milne
 
Edited

Hi Wes

Thanks for the help, I have installed the ExploreStars App on an android tablet, the version i have installed is ES1.9.20051.494 DBVer2.3 FWVer 2.03.

Just to confirm the steps for the 2/3 Star alignment process this is what I am doing using the Android version above;

  1. Menu > Settings >  Set Auto Align to off
  2. click 2 Star Alignment (this takes me back to the main screen)
  3. Menu > Catalogue > Select first star to align (for example Vega), This brings up a screen with the star details. Click Sew to object. This brings up the main screen. 
  4. centre the star on the eyepiece/camera by using the Up/Down/Left/Right buttons
  5. Once the star is centred press the "Enter" button
  6. Align the 2nd star by the same process in steps 3 - 6.
  7. Mount should now be aligned, so use catalogue to goto an object.
  8. Centre the object, and press sync. 
  9. The letter P in a tringle should be shown to indicate that the alignment data is being used.

Can you confirm that this is the correct procedure. 

Thanks.

--
Mounts: ES PMC-8 IEXOS-100
Scopes: TAL-1
Cameras:  Canon 1200D, Canon 70-210mm,  Tamron 150-600mm, 50mm prime. 
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver


Wes Mcdonald
 

Euan 

Almost

The ENTER key is the key that tells the alignment process that you have centered the object.  Sync is only used (in Android and iPad versions) after a routine goto and centering to coordinate all the motor counts to the object ra dec.  During alignment only use the enter button.

Somewhere in there after you pick the object for the alignment you have to press the goto button if the auto alignment is off.  Did you did that?

Wes



On Sun, Jul 18, 2021 at 11:43 AM Euan Milne <euan_milne@...> wrote:

[Edited Message Follows]

Hi Wes

Thanks for the help, I have installed the ExploreStars App on an android tablet, the version i have installed is ES1.9.20051.494 DBVer2.3 FWVer 2.03.

Just to confirm the steps for the 2/3 Star alignment process this is what I am doing using the Android version above;

  1. Menu > Settings >  Set Auto Align to off
  2. click 2 Star Alignment (this takes me back to the main screen)
  3. Menu > Catalogue > Select first star to align (for example Vega), This brings up a screen with the star details. Click Sew to object. This brings up the main screen. 
  4. centre the star on the eyepiece/camera by using the Up/Down/Left/Right buttons
  5. What does the "Enter" button do here??
  6. Once the star is centred click on Sync
  7. Align the 2nd star by the same process in steps 3 - 6.
  8. Mount should now be aligned, so use catalogue to goto an object. The letter P in a tringle should be shown to indicate that the alignment data is being used.

Can you confirm that this is the correct procedure. 

Thanks.

--
Mounts: ES PMC-8 IEXOS-100
Scopes: TAL-1
Cameras:  Canon 1200D, Canon 70-210mm,  Tamron 150-600mm, 50mm prime. 
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver


--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Euan Milne
 

hehe,

I feel like a school boy learning here.

So once I have the alignment star in centre, the enter button is pressed.  

Then after a goto on a chosen object to image. The object is then centred and then press sync? 


--
Mounts: ES PMC-8 IEXOS-100
Scopes: TAL-1
Cameras:  Canon 1200D, Canon 70-210mm,  Tamron 150-600mm, 50mm prime. 
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver


Wes Mcdonald
 

Euan

No worries.  

During the alignment process of 2 or 3 stars after centering use the enter button.  Once alignment is complete you can use the sync button after a goto once that desired object is centered up.

There are mount parameters that the 2/3 star alignment does not resolve.  In particular cone angle error and dec home position error.  When you do a sync on an object (after completing the virtual alignment done with the 2/3 star process) these errors are effectively removed.  This will improve the accuracy of the subsequent gotos.   Unfortunately, the further out of mechanical alignment your mount is in general, the sync correction applied will be more or less effective as you move out away from the place in the sky where you did the sync.  The way to think of this is that when you sync on, for example, a star in Orion, a goto to the Horsehead nebula, also in Orion should be very good.  But a goto for example to the pleiades may not be as good.  But a sync on a star there should make gotos to a star in Taurus be very close.

Using sync on a bright star that is easily found and identified visually is a great way to get deep space objects into your eyepiece/camera field of view.  Instead of doing a goto to the iris nebula for example which you would be unable to see with the naked eye to find it in a red dot finder, do a goto to a bright star nearby.  Center up that one and sync, then do a goto to iris.  Should be bang on.

Wes





--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired