The number of lux depends on the distance from the lamp.

At a distance of 10 cm (very close), this is as follows:

Position             Lux

5                     10000

4                       6400

3                       4000

2                       2200

1                       1000

The further away you sit from the lamp, the less light intensity. 

So on setting 1 or 2 it is under 2500 lux but at a distance of 10cm, that is very close.

For example:

We have now also done a measurement on setting 5 and measured the distance to where it drops below 2500 lux, which is from 25 cm. Probably more pragmatic, so on setting 5 from 25 cm you are under the 2500 Lux.