Each light sensor generates {TAIL ~ a measurable electrical quantity} responsive to the associated vignetted light field, and {HEAD ~ the collective measurable electrical quantities} are responsive to incoming light field 
Each light sensor generates { TAIL ~ a measurable electrical quantity } responsive to the associated vignetted light field , and { HEAD ~ the collective measurable electrical quantities } are responsive to incoming light field
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH