Dynamic PSF (for registration settings)

Adjust registration settings

In some cases, it may be necessary to adjust the stars detection to help registration process finding more stars. This can be done by opening the Dynamic PSF dialog

  • 1 Radius
    Radius

    Size in pixels of the search box.

    The larger the stars, the larger should this value be, although with the latest implementation of the star detection algorithm, the most suitable box size is automatically determined for each star.

  • 2 Threshold
    Threshold

    Threshold value above the noise for stars detection.

    Note

    The default value for threshold is 1.00.

    The median and bgnoise values of the image are determined, then the threshold is: median + [threshold] x 5 x bgnoise.

    Any local maximum above this threshold value is considered a potential star candidate and further analyzed.

    Lowering this value will enable to detect more stars but will spend longer time on each image.

  • 3 Roundness
    Roundness

    Threshold value of star roundnesses. Decrease this value if your stars show small trails.

    Warning

    Ensure you have a good reason to change this value because it may degrade the star detection.

  • 4 Adjust value
    Adjust value

    Ticking this box enables to automatically resize the initial search box radius based on image sampling, if it can be computed from image information, i.e. if focallength and pixel size values are known.

  • 5 Find stars
    Find stars

    Once you have changed the values listed above, pressing this button will launch the stars detection process and report how many stars are found with the current settings.