This parameter determines how many nodes will be scanned across the image to determine the best fit and how many times the nodes will be scanned.
Node count… Determines how many nodes will be scanned across the image. For example, if a Node count of 5 is selected, then 25 nodes will scanned across the image (5 in the X axis and 5 in the Y axis). In general, the Node count should be selected according to the particle size in your sample. In general, if your dataset contains large particles, you should select a limited number of nodes. If your dataset contains small particles, you can select a greater number of nodes.
Iteration count… This parameter determines the number of iterations that will be performed. The larger the number of iterations, the more precise shading correction will be. However, you must also consider the time required to complete each iteration.