I think we need a BLF simple standard, to make repeatable and comparable tests of light power. My dream is a giant table which covers simple performance characteristics of all flashlights BLFers touched.
I wonder would it be possible to create such guidelines on how to measure basic characteristics without sophisticated devices. My aim is to create an instruction, how to obtain numbers, which could describe flashlights performance. This should be easy enough for not advanced user to conduct in home conditions without any additional devices.
What could be measured and quantified?
- Beam width/shape - characteristic giving an idea how wide would the flashlight shine. If possible, good to determine hot spot width and reflected beam width.
The beam width is quite easy to measure, with a protractor and/or against the wall. You can place flashlight (say) 50cm from the wall and measure the highlighted area diameter.
- Luminosity - this is more challenging. Not even thinking of beam integrating, but maybe two readings (on hot spot and on reflected beam) could substitute it? The easiest way is to record how distant objects you can light on, but it’s very subjective. Simple lux-meter or smartphone app could do the job way better, but it requires using “a device”. What do you think? Is there any way to measure how bright the torch shines with bare senses?
- Colour temperature – also quite challenging without devices, but a comparative method could work. If a tested LED is put together with well-known LEDs, that could give an idea. What if a tested LED is put between N219c 4000K and XP-L HI 6500K 1A? Alternatively a white paper sheet and white balance set to a certain (common for all tests) number in the camera could give repeatable readings too. Finally (least preferred) we know there is an App doing the job quite good (as far as I remember from other (djozz?) post).
- Temperature management: check if present and (if so) how much time passes before it kicks in? Workable just with a watch and a hand on the flashlight.
- Mass. It’s an important data anyway, but used together with other characteristics may give interesting info, like: luminosity per 100gram or luminosity*time before temp. management/100g – anyway I mean something telling on how good the mass of flashlight is used (I imagine there are flashlight which are heavy, but due to poor heat transfer they got hot unevenly leading to worse performance than the mass allows for – e.g. UF-1405?)
- UI – this should be systematized I think. Maybe a general assessment on how extensive is UI since many of us has different preferences. Say, 5 points for extensive (e.g. Andurill) and 1 for very simple (e.g. classic hated low-mid-high-sos-strobo)?
I could multiply the factors, but people like to KISS (keep it super simple). The easier the better I think. We could also develop this guidelines, and/or make assessment rules.
Guys, professionally I’m into standards, so this is how I came up with this idea. But surely my flashlight knowledge is rather basic. Wouldn’t even dare to call myself a pro user.
This is just a teaser, I want to hear your opinions since I know I may be very wrong with my assumptions.
Do you think easy, repeatable tests can be described in (kind of) manual so every (also unadvanced) user could perform the tests and receive reliable results? If this would be possible, having so many users it’s possible to create a big database giving an idea of what a particular flashlight really is. This is not possible for one man to achieve. Number of BLFers is our strength. If only every other user puts tests of one flashlight – we are there with a vast database on flashlights from all over the world.