why don't distributors and mfgs list runtimes

[umberto]

I've noticed that some of the big distributors and even the manufacturers when they put a particular light on their site, they do not list the runtimes and the lux or lumen values.....it makes it difficult to compare lights and determine which one would be best for your needs. Why?

Also, how does one convert lux to lumens or vice versa?

 

[Marduke]

It puts a lot of liability on the manufacturer to make claims, as small things such as battery choice, temperature, etc. can affect brightness and runtimes significantly.

Lux to lumens is tricky, as lux is a measure of how well a light throws, where lumens is total output. Lux can change from light to light, even with the same emitter and drive current, just depending on the reflector used.

 

[saildude]

I think some of the funny words mfgs. use is some sort of race to sound better - "usable light" is a good one - 2 lumens from a light that starts out at 45 lumens - and the list goes on -

UK does have a graph on many of their lights -

And as noted above the battery choice can have a vary big choice as is the point where the cutoff occurs - some lights drop to 45% in 15 min but keep on at that relatively high level ( to other lights ) for another 4 hours - so how should that one be described - the whole runtime graph as well as the type of batteries used is needed for a full evaluation.

yes it would be good if there was a standard that all companies tested to - the reviews that were done later by Flashriveiws .com has good info as does the Chevrofreak collection - both are repeatable and standard - without seeing the curve you are still missing the whole picture - I have been doing some runtimes and found some real strange results - I hope to have them together soon for posting.

mb

 

[jzmtl]

I agree, the run graph is really important to see for a user, but I can understand why manufacturers won't provide any. The claimed power and runtime on surefire G2L had me go WOAH, till I saw its magLEDish curve.