This Replacement Vari Sensor Modulefor 285HV Flash from Vivitar measures the light reflected from the subject of a photograph and automatically adjusts the light output of the flash if there's a change (if you move closer or farther from the subject, for instance), so you don't need to change the f-stop on your camera.
The sensor plugs into the front of the flash and can be set for manual or automatic operation at four different f-stops, using the color-coded mode selector dial. Yellow represents the widest lens opening and the greatest automatic operating range, and purple uses the smallest lens aperture for maximum depth of field.
Replacement part for the 285HV flash
Measures and adjusts light from flash
Allows manual or automatic operation
Color coded mode selector dial
In the Box
Vivitar Replacement Vari Sensor Module for 285HV Flash