I bought myself the Dr Meter LX1330B on Amazon and want to compare and contrast the intensity of some of my flashlights. My Google Fu must be bad because after doing a bit of reading, I don't quite understand the best way to test flashlights with this. Direct, non-direct, white wall, etc.
I assume there is a method that tests floodier vs throwier lights without bias? My goal is to measure in a way that duplicates as close as possible the the manufacturer specs so I can compare against those as well as other flashlights.
One of the easiest and cheapest ways to test lumen output is ceiling bounce —- I use to get in one of our bath dressing areas—set the light on the counter facing the ceiling—meter about 6” away beside it (facing ceiling also)—You have to have a light/lights that have known output— fenix—Eagltac are usually pretty close with their readings—- Take a reading with your meter then divide it by the stated lights output—that will give you a correction factor—then test other lights and multiply by that correction factor—- It’s not no exact science but will get you some general ideas what your lights—cells are doing
Are you sure that’s how ceiling bounce is supposed to be done? If both the meter and light are facing the ceiling you may get skewed results from throwy lights projecting their hotspots on the ceiling in direct view of the sensor on the meter.
My recollection is that if your light is pointed at the ceiling, the sensor on your meter should be aimed at the floor. Or some place out of direct line-of-sight of the flashlight’s hotspot.
I use mine in a similar way. I am not looking to test total lumen output. More of a percentage of difference between different cells and different emitters. I use a bathroom in the house that has no windows and place the light meter and whatever light I am testing in the same spot for each measurement. Nice to see the diffenrence in initial turn on versus say 30seconds or even a few minutes after turn on with any given cell or emitter change. It is fun to play with when I am left to myself and nobody else is in the house making fun of why I am in the bathroom with a bunch of batteries and flashlights.
That’s the way I did it for a long time before I made a tube—I was very surprised how close my results were with the tube—- the ceiling in that room was 10’ —the crazy part is,there’s a mirror in there also
seems like what you’re saying to do with the meter—the floor would have to reflect light upward
I want to eventually make one of those tubes. It’s nice knowing the difference but it would be even nicer to be able to put some hard lumen numbers behind those differences. It’s on my ever growing list of stuff to get done. I keep adding stuff to the bottom of the list and the wife keeps adding stuff to the top of it. I think she knows what she’s doing.
