Resolved Issues with Bias Frames - pixel value 65535

Discussion in 'STT Series' started by Piyush, Dec 7, 2017.

  1. Piyush

    Piyush Standard User

    Joined:
    Dec 7, 2017
    Messages:
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    All:

    After a one year break due to moving and getting an observatory built, I am back to imaging. Yesterday evening I took some images and calibration frames.

    While I started processing them, beginning with Bias frames, I noticed that each pixel level is 65535. I went back and looked at the Bias frames from a year back and they had an average value of 1090.

    I am using MaximDL 6 and SBIG STT-8300M. I took Bias frames - both as a single exposure, selecting frame type as Bias, same temperature as Dark/light frames (-30) and as Autosave option with Type as Bias.

    I cannot pinpoint on what I am doing wrong, neither the FITS data show anything different.

    Any thoughts or anyone encountered the same before? Attached is the screenshot of what I am seeing.

    The FITS header shows below:

    DATE-OBS = '2017-12-07T17:51:34' /YYYY-MM-DDThh:mm:ss observation start, UT
    EXPTIME = 0.00000000000000000 /Exposure time in seconds
    EXPOSURE = 0.00000000000000000 /Exposure time in seconds
    SET-TEMP = -30.000000000000000 /CCD temperature setpoint in C
    CCD-TEMP = -29.968750000000000 /CCD temperature at start of exposure in C
    XPIXSZ = 5.4000000000000004 /Pixel Width in microns (after binning)
    YPIXSZ = 5.4000000000000004 /Pixel Height in microns (after binning)
    XBINNING = 1 /Binning factor in width
    YBINNING = 1 /Binning factor in height
    XORGSUBF = 0 /Subframe X position in binned pixels
    YORGSUBF = 0 /Subframe Y position in binned pixels
    READOUTM = 'Raw ' / Readout mode of image
    IMAGETYP = 'Bias Frame' / Type of image
    FOCALLEN = 0.00000000000000000 /Focal length of telescope in mm
    APTDIA = 0.00000000000000000 /Aperture diameter of telescope in mm
    APTAREA = 0.00000000000000000 /Aperture area of telescope in mm^2
    EGAIN = 0.39000001549720764 /Electronic gain in e-/ADU
     

    Attached Files:

  2. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    8,171
    This is camera-related not software related, so I moved this to the appropriate section. There are a few possibilities. One is that there have been changes related to drivers and firmware, and if they're not in sync they could cause problems.

    First of all, download the latest version of the SBIG Driver Checker, and install it. Don't use the built-in update feature because it doesn't update the driver checker itself. Use the new version to update your drivers and firmware. You can get that from:

    ftp://ftp.sbig.com/pub/SetupDriverChecker64.exe

    Try taking bias frames again. Make sure you have IR preflash turned off. Let us know if that changes things.
     
  3. Piyush

    Piyush Standard User

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    Dec 7, 2017
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    Thank you Doug for your quick response, and apologies for putting it in the wrong section.

    First of all - The issue is resolved.

    I was using the latest SBIG 64 bit driver checker, and the drivers were updated. However, one of the firmware was not, and I believe the driver and firmware were not in sync.

    So I uninstalled MaximDL, SBIG64 bit checker, made sure the folders were deleted and reinstalled the SBIG 64 bit checker. Updated the firmware this time and installed Maxim DL again. Switched the camera in setup camera and selected SBIG Universal again. Tested and it works great.

    Thank you again,

    /Piyush
     
  4. Doug

    Doug Staff Member

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    Sep 25, 2014
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    8,171
    That would do it. We've made some major improvements to the RBI Preflash feature, and unfortunately this had to be a "breaking change" - old/new drivers/firmware don't mix.
     

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