Page 2 of 2 FirstFirst 12
Results 11 to 16 of 16
Like Tree17Likes

Thread: New Autoguider - First Testing!

  1. #11
    CamelHat's Avatar
    CamelHat is offline Bronze Supporter
    Points: 50,452, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 26.0%
    Achievements:
    50 Posts Achievement!5 Threads Achievement!First 1000 Experience Points2 Posts Achievement20 Posts Achievement!
    Join Date
    Dec 2011
    Location
    Santa Barbara, CA
    Posts
    5,655
    Points
    50,452
    Level
    100
    Thanks
    1,136
    Thanked 1,654x 1,352 Posts

    Default Re: New Autoguider - First Testing!



    Quote Originally Posted by geethq View Post
    i though you need to clear all those settings when guiding and let PHD to calculate and compensate them.
    It is impossible for PHD to compensate for backlash the way the mount's built-in backlash compensation can do it. What the mount does is spin the motor real fast for a predetermined amount of time when the direction changes. PHD can only tell the mount to spin at the same guide rate as any other guiding action, for an extended period of time. So it can't even get close to making the mount do what it should be doing. I always use it with lin_guider and it seems to work fine. It is a true backlash compensation that makes the mount behave equivalent to one that has less backlash. I would be interested in knowing the counter arguments though, I would presume they are not valid.
    Juno16 likes this.
    ... Henk. Telescopes: 6" Mak-Newt (Comet Hunter), ES ED127CF, ES ED80, Zhumell Z12, Coulter Odyssey 10, AT6RC, Venture RX-7, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S, AVX, LXD55, Tiltall, Cameras: Fuji X-a1, Canon SX40, Xt, XSi, T6, ELPH 100HS, DIY: Dob and camera barndoor trackers, afocal adapter, Dob with foldable base and Az/Alt setting circles, Accessories: SSAG, Plossls, Barlows, Telrad, laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: DSS, ImageMagick, PHD, Nebulosity, Photo Gallery, Gimp, CHDK

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  2. The Following User Says Thank You to CamelHat For This Useful Post:

    Juno16 (01-13-2019)

  3. #12
    geethq's Avatar
    geethq is online now SUPER GIANT
    Points: 16,967, Level: 90
    Level completed: 5%, Points required for next Level: 333
    Overall activity: 38.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!First 1000 Experience Points
    Join Date
    Oct 2012
    Location
    Sri Lanka
    Posts
    793
    Points
    16,967
    Level
    90
    Thanks
    290
    Thanked 342x 261 Posts

    Default Re: New Autoguider - First Testing!

    Quote Originally Posted by CamelHat View Post
    It is impossible for PHD to compensate for backlash the way the mount's built-in backlash compensation can do it. What the mount does is spin the motor real fast for a predetermined amount of time when the direction changes. PHD can only tell the mount to spin at the same guide rate as any other guiding action, for an extended period of time. So it can't even get close to making the mount do what it should be doing. I always use it with lin_guider and it seems to work fine. It is a true backlash compensation that makes the mount behave equivalent to one that has less backlash. I would be interested in knowing the counter arguments though, I would presume they are not valid.
    its just something i read somewhere so i never set it from HC on my AVX. i'm not sure if its logical or not though.

    ps, i found the source. its from page 14. "PHD2 Best Practices" Bruce Waddington,Andy Galasso
    its from PHD website itself.
    https://openphdguiding.org/phd2-best-practices/
    https://openphdguiding.org/PHD2_BestPractices.pdf
    Juno16 likes this.
    Imaging Setup

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    : 10" F3.9
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Astrograph on
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    EQ6-R Pro
    Cameras: Nikon D5300 Full spectrum + Optolong 2" UV/IR cut with Baader MPCC mark III
    Guiding: 50mm Orion scope, ASI120MM mini camera
    Accessories: Celestron 15x70 Bino, GSO 3x ED & 5x APO
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    Previous Setup (12/17- 9/18): 8" F4 GSO Newtonian on Celestron AVX, Nikon D5300, GSO 2" CC

  4. The Following User Says Thank You to geethq For This Useful Post:

    Juno16 (01-13-2019)

  5. #13
    CamelHat's Avatar
    CamelHat is offline Bronze Supporter
    Points: 50,452, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 26.0%
    Achievements:
    50 Posts Achievement!5 Threads Achievement!First 1000 Experience Points2 Posts Achievement20 Posts Achievement!
    Join Date
    Dec 2011
    Location
    Santa Barbara, CA
    Posts
    5,655
    Points
    50,452
    Level
    100
    Thanks
    1,136
    Thanked 1,654x 1,352 Posts

    Default Re: New Autoguider - First Testing!

    Quote Originally Posted by geethq View Post
    its just something i read somewhere so i never set it from HC on my AVX. i'm not sure if its logical or not though.

    ps, i found the source. its from page 14. "PHD2 Best Practices" Bruce Waddington,Andy Galasso
    its from PHD website itself.
    https://openphdguiding.org/phd2-best-practices/
    https://openphdguiding.org/PHD2_BestPractices.pdf
    They have one valid argument namely that preloading may reduce or eliminate the backlash in one direction, in which case any compensation implemented by the handset will compensate when not wanted. This will interfere with PHD because it will cause nonlinear/asymmetric behavior while PHD expects symmetric behavior.

    I don't know, the AVX handset allows you to compensate independently in each direction so you can use one direction only if you know how you preload the mount. I am not convinced by their argument. They also state that their algorithm can't handle large backlash. So then why disable the built-in backlash? It might help fix things because it is much more effective. I believe that if you use it with care it should be beneficial.
    Juno16 likes this.
    ... Henk. Telescopes: 6" Mak-Newt (Comet Hunter), ES ED127CF, ES ED80, Zhumell Z12, Coulter Odyssey 10, AT6RC, Venture RX-7, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S, AVX, LXD55, Tiltall, Cameras: Fuji X-a1, Canon SX40, Xt, XSi, T6, ELPH 100HS, DIY: Dob and camera barndoor trackers, afocal adapter, Dob with foldable base and Az/Alt setting circles, Accessories: SSAG, Plossls, Barlows, Telrad, laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: DSS, ImageMagick, PHD, Nebulosity, Photo Gallery, Gimp, CHDK

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  6. The Following User Says Thank You to CamelHat For This Useful Post:

    Juno16 (01-13-2019)

  7. #14
    jaetea's Avatar
    jaetea is online now Awaiting Maven Status
    Points: 153,007, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 23.0%
    Achievements:
    365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts AchievementFirst 1000 Experience Points20 Posts Achievement!
    Join Date
    Sep 2011
    Location
    Honolulu, HI
    Posts
    7,664
    Points
    153,007
    Level
    100
    Thanks
    1,209
    Thanked 2,994x 2,330 Posts
    Blog Entries
    17

    Default Re: New Autoguider - First Testing!

    Quote Originally Posted by CamelHat View Post
    They have one valid argument namely that preloading may reduce or eliminate the backlash in one direction, in which case any compensation implemented by the handset will compensate when not wanted. This will interfere with PHD because it will cause nonlinear/asymmetric behavior while PHD expects symmetric behavior.

    I don't know, the AVX handset allows you to compensate independently in each direction so you can use one direction only if you know how you preload the mount. I am not convinced by their argument. They also state that their algorithm can't handle large backlash. So then why disable the built-in backlash? It might help fix things because it is much more effective. I believe that if you use it with care it should be beneficial.
    This is a great topic and question to ask Andy or Bruce over on the Open PHD Guiding Google Groups. Might as well get it from the source instead of just guessing. Henk, if I could trouble you to ask the question, I would be very interested in their response. KenGS post over there all the time as he is one of the contributors.
    https://groups.google.com/forum/?utm...guiding/topics

    Thanks,
    JT
    geethq and Juno16 like this.
    Main: C-stron CPC1100 #2
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    :
    8" f/7.5 Dob mounted Newt AP
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    :
    TPO 6" RC f/9 &
    ES 80mm f/6 APO G&G Scope: Meade 102mm f/7.8
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Guide Scopes: 70 & 80mm fracs Mounts: C-stron AVX CGEM & GT Alt-Az, Cameras: Canon T3i 2, ASI120MC Binos: 10X502,10.5X70,15X702, 25X100 EPs: ES: 21 100°, 30 82° X-Cels: 9,12,18,25 Clubs: RCA & HAS

    HOME »
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    I never met a scope I didn't want to keep.
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    "My God, it's full of stars."
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  8. The Following User Says Thank You to jaetea For This Useful Post:

    Juno16 (01-13-2019)

  9. #15
    CamelHat's Avatar
    CamelHat is offline Bronze Supporter
    Points: 50,452, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 26.0%
    Achievements:
    50 Posts Achievement!5 Threads Achievement!First 1000 Experience Points2 Posts Achievement20 Posts Achievement!
    Join Date
    Dec 2011
    Location
    Santa Barbara, CA
    Posts
    5,655
    Points
    50,452
    Level
    100
    Thanks
    1,136
    Thanked 1,654x 1,352 Posts

    Default Re: New Autoguider - First Testing!

    Quote Originally Posted by jaetea View Post
    This is a great topic and question to ask Andy or Bruce over on the Open PHD Guiding Google Groups. Might as well get it from the source instead of just guessing. Henk, if I could trouble you to ask the question, I would be very interested in their response. KenGS post over there all the time as he is one of the contributors.
    https://groups.google.com/forum/?utm...guiding/topics

    Thanks,
    JT
    Since I am not a PHD2 user I am a bit reluctant to start asking questions at the PHD forum but I am a member and searched the forum first. Here's one from Bruce Waddington 10/7/18:

    "Hi Lawrence. You should leave the backlash parameter in the mount set to zero. Most mounts have this capability and it can work ok for visual use, but it’s usually a disaster for guiding. This is covered in our Help manual and there’s an example in the guide log tutorial showing the miserable results you can get when compensation is enabled in the mount. The PHD2 feature is different because it’s adaptive, the amount of compensation is continually adjusted based on the results. The fundamental problem is that the observed amount of backlash is not constant across sky positions and is quite often associated with stiction."

    It would help if they could be more specific about what causes the backlash to not be constant. If it is the preloading because the counterweight bar position changes, I think that can be mitigated. If it is stiction then that would affect the hand controller BC as well. It still sounds to me like if the hand controller BC works well at all positions that it should not be a problem.

    With that said I now have a better understanding of the potential problems and would change how I would use it - one-sided when preloading, and test the BC for various positions.
    Juno16 likes this.
    ... Henk. Telescopes: 6" Mak-Newt (Comet Hunter), ES ED127CF, ES ED80, Zhumell Z12, Coulter Odyssey 10, AT6RC, Venture RX-7, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S, AVX, LXD55, Tiltall, Cameras: Fuji X-a1, Canon SX40, Xt, XSi, T6, ELPH 100HS, DIY: Dob and camera barndoor trackers, afocal adapter, Dob with foldable base and Az/Alt setting circles, Accessories: SSAG, Plossls, Barlows, Telrad, laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: DSS, ImageMagick, PHD, Nebulosity, Photo Gallery, Gimp, CHDK

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  10. The Following User Says Thank You to CamelHat For This Useful Post:

    jaetea (01-13-2019)

  11. #16
    Juno16's Avatar
    Juno16 is offline SUPER GIANT
    Points: 10,054, Level: 69
    Level completed: 35%, Points required for next Level: 196
    Overall activity: 38.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!365 Days+ Registered Achievement!50 Posts Achievement!
    Join Date
    May 2016
    Location
    Long Beach Mississippi
    Posts
    1,111
    Points
    10,054
    Level
    69
    Thanks
    1,061
    Thanked 613x 428 Posts

    Default Re: New Autoguider - First Testing!

    Hi Everyone,

    Thanks all for the very valuable information.
    I have lots of reading to do and thanks for the great links!

    I just have to get out and work with it. I have learned a lot from your contributions to this thread.
    I reset the settings in PHD. Hopefully, with good PA, the RA will settle down some. If not, I will be checking with you, JT, for those links.
    I will try some imaging regardless of how the RA looks though. Hopefully there will be some improvement over no guiding at all and then tweak from there. My biggest issue with unguided (60 second exp.) was the 2-4 images out of 10 where there was significant star trailing (thinking it is periodic error).
    Unfortunately, the sky predictions for tonight were good, but we have been under thick cloud cover all day and it does not look good. Hopefully tomorrow night I can start working with this. Many new things to try.

    Thanks again all!

    Jim
    geethq likes this.

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    : Explore Scientific ED102 Triplet APO,
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    130 SLT.
    EP: 12 and 32 mm Plossl, 5 mm Celestron X-Cell, Agena Starguider ED8mm & ED12mm, ES 32mm 2” 62 degree, 2x
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    Mounts: Celestron AVX with
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    MM Autoguider, SLT; Binoculars: Bushnell 10X50;
    Camera: Nikon D3300, DigiCamControl, PHD2, SharpCap v3.2, StarTools, PE14
    Dog: Jack

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

 

 
Page 2 of 2 FirstFirst 12

Similar Threads

  1. CCD Deep Sky Imaging IC 405, vdB 34, Melotte 31 (testing, testing)
    By jthommes in forum Astrophotography Forum
    Replies: 12
    Last Post: 04-06-2018, 05:27 AM
  2. M27 while testing
    By Testgear in forum Astrophotography Forum
    Replies: 14
    Last Post: 08-21-2017, 02:39 PM
  3. Indoor autoguider testing
    By CamelHat in forum Astro Imaging Forum
    Replies: 7
    Last Post: 11-21-2015, 01:23 PM
  4. Replies: 7
    Last Post: 12-30-2014, 11:03 PM
  5. Testing Welcome
    By testingtesting in forum Forum Welcomes Introductions
    Replies: 5
    Last Post: 09-18-2009, 09:24 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 08:13 AM.