LED lighting "distance"....

LED lighting \"distance\"....

Ok.. so this may be a strange/tough question.. but has anyone have any information on how "far" light from a LED will typically travel or is visible... I know there are probably a million things that could effect this.. but I'm trying to figure out how maybe 1 to 10mw LED's would project light and how it would compare to say a 15watt flourescent light. I'm not worried about lumens say much as I guess candela? I'm really not sure how to go about this question.. maybe someone with experience could better phrase this...

thanks!

Re: LED lighting \"distance\"....

The throw numbers at flashlight reviews.com is roughly the distance an object is visible in meters. YMMY.
More info here
Incandecent bulbs tend to be omnidirectional. LEDs usually are very directional so the beam angle as well as the brightness of the LED will determine the throw.
ledmuseum has comparisons between leds but his numbers are in mcd not distance. I have not come across mcd vs. distance charts.
In my experience light from raw leds do mot light things up much more than 10 feet away. beyond that a reflector or optic is used to focus the light.

Re: LED lighting \"distance\"....

For a fascinating discussion of the objective and subjective aspects of throw, check out the thread, Quantifying urban throw (the "washout effect").

Re: LED lighting \"distance\"....

www.led.lightwavesconcept.com has a photometric chart for their LED bulbs that provides how much LUX you get at a certain distance

Re: LED lighting \"distance\"....

Ok thanks guys. Here's one then.. how do you think the throw of a 110 degree 2mw LED would compare to a 10 degree 2mw LED?
Would it be comparable because they are both 2mw, or would thr 10 degree really out do it distance wise...

Re: LED lighting \"distance\"....

Lots of things have to be considered in *throw*. The most noticeable is the sheer amount of photons available to be focused to bounce off a target at distance and the mechanism that directs or focuses them towards a distance targer.
This makes it obvious that a tighter arc results in more electrons in that arc at a distance so the 10degree LED would have more electrons in a smaller angle at a distance thus better throw.
Think of it as a watter hose nozzle. If you put it on spray you can soak a car quickly but at 20 feet you would take awhile to just soak a tire. Switch to a stream pattern and the tire is soaked in little time.

Re: LED lighting \"distance\"....

there's no replacement for raw horsepower! yes you can made better use of what ponies you have by going to a lighter weight chassis etc. in the end, how much HP is what counts.

example: former throw king for small lights was Don's L1-PR-T 917 which used a 3watt combined with 27mm PM6 reflector.

Li-917 has tremendous throw, but it's beam at distance was tiny. compared that to MR-X X3T. mine puts out lumens equal to Surefire M6 or 250+ lumens out the front end.

MR-X's 52mm reflector and more horsepower will throw aprox. same distance as L1-917, but bright spot is way larger.

so you really need both horse power and large reflector for effective lighting at distance.