RaustBD

hey, does candlepower or lumens directly convert to lux by any formula?

wait, actually, I reread your post, now I think I've got it... I just need to find out what lux I want to be too bright for the stuff to survive in, then convert lux to lumens, get the lumen values of various light sources, and I'm all set!

...yeah, that's great, except how am I going to get my hands on a massive bonfire... Back to the drawing board...

darn it... this makes things more complicated. Okay, you know what? Maybe I should just do a test. I'll go out to as dark a night as I can manage, light various light sources, and see how far away from the source I can go and still be able to read a book by its light. Then I'd take the ratios or something, and convert them.

Thanks for the help, but I'm still quite confused... Maybe I should rephrase it in terms more useful to my book: I've decided that the substance I mentioned is dispelled by light, and that a fire-lit torch would clear an area with a radius of about 7 feet. I'm trying to find out what kind of clearing power other light sources would have. If a candle really only has 1 lumen of lighting power, and what you said about the radius thing being proportional is true, then that would mean a candle would only clear the stuff in a field with a radius of... six tenths of an inch. That just doesn't sound right to me... am I missing something?

Hey, I'm writing a book, and in it there's a sort of substance in it that's neutralized by bright light. Recently I heard about lumens, the unit of measure for light, and I was wondering if anyone knew about how lumens scale... Like, if something has twice the lumen level of something else, would the radius of the circle of light it cast be twice as big? How many lumens would a fire-lit torch have? A candle? A Heavy-duty flashlight? The sun by the time its rays reach the earth? A massive bonfire? I'd really appreciate it if somebody could help me out with this.