Where IS the "point of max "efficiency vs lumens"?

LED Flashlights – General Info
21

A better metric might be “lumen-hours” - lumens multiplied by how long you get them for. For a given LED, cell and flashlight form factor, the best light is the one that gives you the most lumen-hours in the mode you expect to use most often. That way, you’re accounting for all efficiency factors like LEDs, drivers, spring resistances, cell models and whatnot.

Unfortunately, manufacturers don’t generally supply that information, but some flashlight reviewers do runtime graphs of output over time, and you can figure it out from those - you’re basically working out the area under the line. You also get the bonus of being able to see how well-regulated the light output is - flatter lines are better regulated.

22

“lumen hours” varies with the battery/cell though.

23

That’s true.

Reviewers who put in the kind of work it takes to get runtime charts will make sure to use decent cells, and you can multiply / divide to account for capacity differences, but yes, there’s still room for variation.

The holy grail is to get the same reviewer using the same cell to review all of the lights you’re interested in :slight_smile: Selfbuilt on CPF was the one whose reviews first showed me how remarkably useful that could be.