The optical filter control is not available for the selected camera
This VB example uses the minimum and maximum optical filter values to initialize the slider control:
Private SubForm_Load() Slider1.Min = ActiveDcam1.GetOpticalFilterMin
Slider1.Max = ActiveDcam1.GetOpticalFilterMax
Slider1.Value = ActiveDcam1.OpticalFilter
If the currently selected camera doesn't support software optical filter control, the method will generate an error.