Agreed @mwiener and @wey2go  this is definitely a "your mileage may vary" type of situation, no two camera deployments are every going to have the same exact illumination conditions.  If you were looking for a rule of thumb, from experience with my own customers, I'd say between 40 and 50 feet.  But again, it's an "it depends" type of answer, in the example I used for my driveway MV71, it does improve the overall scene at night, both up close and out to 70-80 feet into the street. ... View more