Staff Assigned: Owen Lawrence AO8-T and STT-8300 guiding issues

Discussion in 'Demo User Tech Support' started by JoshuaFrechem, Oct 2, 2018.

  1. JoshuaFrechem

    JoshuaFrechem Cyanogen Customer

    Joined:
    Oct 1, 2018
    Messages:
    29
    Location:
    Virginia
    Hello, I currently have my setup tripod mounted and I have to set up most nights I image. I find that the AO calibration often fails and I have to slew so that my guide camera is in an open cluster. Are there any tips on calibration and is there a way to dark subtract during calibration, not just actual guiding?

    Also, I will often come back after some time and the guide star is lost for seemingly no reason as I wasn't there to witness what happened. Is there a way to reaquire a lost guide star by prompting the image to stop, astrometrically reposition the scope and start guiding again? I also have the issue that, while the drive and AO calibrate successfully, the AO unit will max out and give the error that guider relays would not respond even though I am guiding using the telescope selection. Should I use an ST-4 cable for more reliable guiding or is this some other issue?

    Thank you!
     
  2. Tim

    Tim Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    1,513
    Are you using the MaxIm DL demo? I do not see a valid license in your name.

    If this is a hardware question related to your SBIG hardware, it should be posted to the SBIG forums on the main page, not this forum (MaxIm DL Demo User Tech Support). No one will see it here.
     
  3. JoshuaFrechem

    JoshuaFrechem Cyanogen Customer

    Joined:
    Oct 1, 2018
    Messages:
    29
    Location:
    Virginia
    Yes, I am using a MDL6 license that is under the same email as my forum account. I posted this here because I thought it would have to do with how MDL handles the acquisition during calibration (it won't do auto darks for anything but guide frames, not calibration) and it often loses the calibration star on the second move even though the calibration star is bright, round and away from the edge.
     
  4. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    4,897
    You should only need to calibrate the AO unit itself once, ever, unless you physically unbolt the AO from the front of the camera and reorient it. You will need to recalibrate the "mount bump" only if you are using a German Equatorial mount and you flip over the pier, or if you rotate the camera assembly in the eyepiece holder.

    Since recalibration is rarely needed, I recommend you pick a relatively bright isolated star (e.g. 8th-9th magnitude) for calibration. Then move to your target and start guiding.

    The ST-4 cable may be more reliable, depending on your telescope mount and control software. If your mount has an appropriate port I would recommend using it. If the guiding is more reliable as a result then you have your answer!

    If the "bump" is unable to keep up with the drift rate of your mount, that may cause loss of the star. In that case, you might want to increase the bump duration. Don't increase that more than necessary, but it should be a big enough bump to ensure that the star doesn't drift outside the range of the AO.

    At this time there is no automated option for reacqusition. There are third-party scripting programs such as ACP, which work with MaxIm DL, and may have additional capabilities in this area.
     
  5. JoshuaFrechem

    JoshuaFrechem Cyanogen Customer

    Joined:
    Oct 1, 2018
    Messages:
    29
    Location:
    Virginia
    Hi, Doug. Thank you for your response! I was considering ACP once I purchase MDL6 for that very reason as it didn't appear there was a protocol built in except for meridian flip.

    I have been calibrating my drive and AO every night because I don't have it permanently set up yet. The past few days I have just left it outside due to good weather and found that each night if I didn't calibrate the drive, it failed to "bump" properly, but the AO was fine as I expected (and as you just verified). Most of the issues seem to be between MDL and my CGX as I get some bad behavior on pier flips and the AO panel doesn't like calibrating my drive.

    I will give your recommendations a go and will come back with any other questions I may have. Thank you!
     
  6. Bob Denny

    Bob Denny Cyanogen Customer

    Joined:
    Oct 12, 2014
    Messages:
    637
    Location:
    DC-3 Dreams, SP, Mesa, Arizona +1 480 396 9700
    ACP will manage the AO 100% hands off, even if you use a camera rotator. No need to recal anything on flip or PA changes.
     
  7. Jenny Hatchell

    Jenny Hatchell Standard User

    Joined:
    Jan 12, 2015
    Messages:
    8
    AO Calibrate Drive also fails repeatedly for us, even when we have bright stars near the middle of the frame. It loses the star on the 2nd slew and the 4th(?), the vertical legs of the L. In these images, the star is appearing as a vertical streak. The horizontal-move images are fine. We did manage to calibrate once in 2016 so are OK to guide for now, but it would be good to know we could recalibrate if we needed to.

    We're running a STT with AO-8 and an Astrophysics 1100 mount.
     
  8. Owen Lawrence

    Owen Lawrence Staff Member

    Joined:
    Oct 1, 2014
    Messages:
    1,228
    Hi Jenny,

    What version of MaxIm DL are you using? If it's not V6.18 you may be missing fixes for some of these issues. If it is, try enabling "Access camera from a separate thread" in your Camera Control Window | Options dialog box.

    We're waiting for openings in the clouds to do some testing on some more fixes before passing a new AO plugin to customers, too. I'm hopeful that it'll improve Joshua's situation, too.

    In the meantime, can you please upload a zip archive of your Documents\MaxIm DL V6\Settings? Include log files of a session in which this problem appeared.

    - Owen -
     
  9. Jenny Hatchell

    Jenny Hatchell Standard User

    Joined:
    Jan 12, 2015
    Messages:
    8
    Owen, thanks for getting back. We're on MaxIm version 6.13 and are looking into making the upgrade (when our current batch of student observing nights have finished). In the meantime, here's the requested Settings archive, with a Log directory included with 20181002.log. In the log, after some flatfields, you'll see us slew to Alpha Cyg and then try the guider calibration several times. There doesn't seem to be much detail on the guider setup here. Was this the log you wanted?
     

    Attached Files:

  10. Owen Lawrence

    Owen Lawrence Staff Member

    Joined:
    Oct 1, 2014
    Messages:
    1,228
    Hi Jenny,

    Thanks for the settings. I see that you have threading enabled for Camera 1 and Filterwheel 1, both SBIG devices. We discovered a problem after 6.13 was released that affects that configuration. I recommend you uncheck the two threading options for those devices. It should be okay to leave it enabled for the ASCOM device.

    Unfortunately that version is so old that I doubt the new AO plugin I mentioned can work with it. Your best bet is to upgrade to the latest version whenever you're ready. Hopefully by then we'll have produced a patch for any outstanding problems.

    - Owen -
     

Share This Page