en-HelpPluginsEclipsestack

Stack (total solar eclipse)

This tool allows to stack images of the total phase of a solar eclipse.

The "Blend" frame allows to tune how saturated and underexposed zones are excluded and intermediate zones progressively blended in the final image.

• The "Saturation" threshold is the luminosity level above which pixels are totally excluded from the stack.
• The "High blend level" is the threshold above which pixels are progressively, "weakened" in the stack. Pixels at this level are wheighed at 100%, and the weight decreases as the luminosity increases up to the saturation level where the weight reaches 0%.
• The "Low blend level" is the level under which pixels are progressively "weakened" in the stack. Pixels at that luminosity are wheighed at 100%, and the weight decreases with the luminosity, until the black level, where the wheight reaches 0%. Pixels with a level between the high and low blend levels have a 100% weight.

The "Inner corona" frame allows to tune how the artefacts due to the transition between the inner corona and the lunar edge are suppressed.

• The X and Y fields allows to define the sun's center.
• The internal and external radii define the zone in which the algorithm looks for a luminosity maximum starting from the center, this maximum marks the start of the inner corona. Both circles are displayed in green on the image.
• The blending distance is the distance along which the start of the inner corona is progressively blended in the result.

Pay attention to defining internal and external circles fitted to both the start and the end of the eclipse.

The "Shutter" field defines the shutter speed for each image. This parameter is very important to get an homogenous luminosity profile in the stacked result.

At last, the "Crop rectangle" frame allowd to define the images zone which will be stacked, and the "Stack" button starts the stacking process, as in the regular stack tool.

Use the "tickets" page of the project, https://sourceforge.net/p/lynkeos/_list/tickets, to report bugs or suggest improvements.