Re: How To Do an ExploreStars Assisted "Physical Polar Alignment" As Long As You Can See Polaris #TECHNICAL #astrophotography

jrichard333 <>

Thank you Sir Jerry,


Thank you for sharing this document.  It has allowed me to move from planetary imaging to Messier imaging.


Things gathered from my award winning self-proclaimed journal “thinking hurts my brain, and reading hurts my eyes.”  Again not seeing Polaris, I did the following:

1.        I aimed the mount/ scope North (using my Android compass).

2.       Varied my latitude from 26 to 32 degrees (32-degrees is the magical number for getting to Mirach) as I slewed to Mirach.

3.       I kept slewing back and forth from an unseen Polaris to a seen Mirach, until Mirach was dead centered. 

4.       Then from home position I slewed to M31, M33, and M45.  Some were well within the frame of my liveview finder 

5.       Length of time for setting up:  an hour or two.

6.       Now I have to focus on polar alignment so I can image longer.

7.       I view Mirach as my Goto calibrator for M31, M33, and M45.

8.       I did not do a 2-star alignment



1.       Canon 70D (stock)/ Celestron’s C90 finder scope/ Sigma 150-600mm lens (various focal lengths not exceeding 300m) but soon I will J.

2.       iEXOS-100 mount.


Camera Setup:

1.       Exposure Simulation engaged

2.       Long exposure/ high ISO noise reduction (eliminates hot/ stuck/ dead pixels)


Taking my time learning and slowly moving forward.


What things look like when you don’t think about using long exposure and high ISO noise reduction.  Hot pixels look cute….reds, whites, and blues doing the electric slide throughout the image.  I would have had more exposures, but I imaged myself right into a tree J.  This is my second attempt at M31.  1st attempt consisted of 5-second exposures and who wants to see that J.


Image details:

M31 2nd attempt:

Number of images:  7

Exposure per image:  30-seconds

ISO:  800

FL: 302mm

Bortle: 8-9

Imaging software:  Sequator/ FastStone


Image 2 details:

M33 1st attempt (A disturbance in the force):

Number of images:  10

Long exposure/ ISO noise reduction enabled

Exposure per image:  15-seconds

ISO:  1600

FL: 244mm

Bortle: 8-9

Imaging software:  Sequator/ FastStone


None of these items can be seen with the naked eye or through exposure simulation.  Mirach can be seen with exposure simulation only.




From: [] On Behalf Of Jerry Hubbell - Explore Scientific VP Engineering
Sent: Saturday, September 21, 2019 11:44 AM
Subject: [ESPMC-Eight] How To Do an ExploreStars Assisted "Physical Polar Alignment" As Long As You Can See Polaris #astrophotography #TECHNICAL


I received an email from Wes polar alignment. We have been working together as Wes has been digging in hard to understand the mathematics and code behind the ExploreStars 2 and 3-star "virtual" alignment routines. We have had some good discussions over the past few months about how to improve the "virtual" alignment provided by ExploreStars. Wes has made good progress on determining the source of errors in the mount and in creating the mount model. I will leave it to him at some point down the road to announce his findings and we will announce any modifications we will be making to the software if and when it comes about. 

In the meantime, back to the email Wes sent me, it contained a link to an easy, iterative method that anyone can use to "physically" polar align their PMC-Eight mount system assisted by the ExploreStars application. The only catch is that you need to be able to see Polaris. This method is independent of and does not use any imaging based alignment tools, all you need is a good eyepiece, preferably a cross-hair eyepiece such as the Meade 12 mm .

Here is the link to the procedure:

Please take a look I would be interested in your thoughts on this procedure.

Jerry Hubbell
Vice President of Engineering
Explore Scientific, LLC.
jrh at
1010 S. 48th Street
Springdale, AR 72762

Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home

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