The IRV80451 Variable Iris attachment works as an accessory to the standard lens. The variable iris is used to control intensity and to increase the depth-of-field. This reduces the necessity to refocus for changes in distance.
This variable irisis for use with IRV models that use the Infragon objective lens. The Infragon lens is standard with models IRV84499A, IRV84499A-5, IRV85268A, IRV85268A-5, IRV85100, IRV85100-5, IRV85100A, IRV85100A-5, IRV85050A, IRV85050A-5, IRV85051A and IRV85051A-5. This variable iris is also compatible with models IRV84499, IRV84499-5, IRV85100 and IRV85100-5 when used with the standard Infragon lens.