Flats

Discussion in 'STX and STXL Series Cameras' started by Mike Hambrick, Dec 8, 2022.

Page 2 of 2
  1. Colin Haig

    Colin Haig Staff Member

    Joined:
    Oct 27, 2014
    Messages:
    8,077
    Location:
    Earth
    Yes. The trick is to have enough stars to cover the whole field without them trailing due to tracking error.
    Hard to say. Try Multi-star guiding and see if it helps any.
    Since your camera and scope give you about 1.04" arcseconds/pixel, that may be better than your seeing conditions, so you may just end up fighting the seeing which will exceed both the mount's guiding performance and the camera resolution.
     
    Colin Haig, Jan 4, 2023
    #21
  2. Mike Hambrick

    Mike Hambrick Cyanogen Customer

    Joined:
    Jul 13, 2016
    Messages:
    458
    Location:
    Orange, Texas
    Hi Colin & Doug

    I would like to get some feedback to make sure that I am setting up the multi-star guiding correctly. I tried it last Friday, but I am not sure I set it up correctly. I did not get any error messages, and the mount is definitely being guided. In the guide graph below there is some improvement in the Y (Dec.)-axis RMS error over what I typically see. The X-axis performance is at least as good and certainly not worse than what I typically see.
    • In the guider settings I selected the multi-star guiding.
    • I took an image through the guide camera (FW8G-STXL)
    • I clicked on one of the stars in the image and then did the guider calibration. The calibration was successful (see photo), but the calibration was done on a different star than the one I selected (the circled star in the photo)
    • After the successful calibration I clicked on two stars (indicated in the photo below with the triangle and circle) and then started tracking.
    • During the tracking, the full frame image of the guide camera remained visible. I believe this is typical based on what I read in the manual.
    • Based on what I saw in several different attempts at multi-star guiding that evening, are my attempts to select the calibration or guide stars really doing anything ?
    One of the exercises I did Friday night was to take some more images at various positions in the sky to see how much if any tilting is going on. This time I took guided exposures of varying length ranging from 5 seconds to 600 seconds to see if there is any effect coming from the exposure time. Is there any value to doing a tilt analysis on any of these images ? If so, let me know and I can put them in Dropbox for you.

    Finally, are you familiar with the Hocus Focus add-on to the N.I.N.A. software. I understand that it can do analysis of the stars in an image to look for tilt and other issues. I thought that before I invest in another software subscription (CCD Inspector) that I could try using the free Hocus Focus app to see if I can get any meaningful information out of it.

    Mike
    upload_2023-1-9_9-58-59.png

    upload_2023-1-9_9-58-9.png
     
    Mike Hambrick, Jan 9, 2023
    #22
Page 2 of 2

Share This Page