WHAT ARE LUMENS?

A Lumen is the standard unit of measure for the total amount of light from a source, in all directions.  

This tells you how much light the torch produces, with no regard for the area it covers, unlike Lux. This is demonstrated by the example below:

Both torches are producing 1000 Lumens of light, however, the top torch has a narrower beam which means a higher Lux.

While the lower torch has a lower Lux due to the wider beam.

Example:

1000 Lumens concentrated into an area of 1-meter square, would equal 1000 Lux

1000 Lumens spread over 10 square meters, equals only 100 Lux

So when looking at the performance of a torch, you need to consider both Lumens and Lux; one without the other is of little use!