The iris control is not available for the selected camera
Example
This VB example uses the minimum and maximum iris values to initialize the slider control:
Private SubForm_Load() Slider1.Min = ActiveDcam1.GetIrisMin
Slider1.Max = ActiveDcam1.GetIrisMax
Slider1.Value = ActiveDcam1.Iris
End Sub
Remarks
If the currently selected camera doesn't support software iris control, the method will generate an error.