It really depends on how well your flashlight can collimate, this method is almost irrelevant for regular reflector LED flashlights.
I made a separate post to explain everything: The proper way of calculating lux / cd / candlepower
It really depends on how well your flashlight can collimate, this method is almost irrelevant for regular reflector LED flashlights.
I made a separate post to explain everything: The proper way of calculating lux / cd / candlepower