Hi again — I am 99% sure I know what’s happening. I read the list of filters (by name) coming from MaxIm. That info comes from the Setup Filters list in MaxIm (Camera.FilterNames). I get a contiguous list. Throughout I use the numbers and names for various purposes. There are places where I look at which filter MaxIm currently reports as being selected... and make decisions. This way I can avoid having to create a software “shadow filter wheel” which follows the real one. Unfortunately the number I get from reading “currently selected filter” (Camera.Filter) is the “raw” number. If there is a gap, the index in the list and the current filter number don’t match and that’s what creates the confusion you’re seeing.