PPF (µmol m-2 s-1) conversion to Lux is depending on the type of light. Following tables from AllCat Instruments show conversion factors for most common light types.
PPF (µmol m-2 s-1) to LUX
Sun
54
Fluorescent white lamp
74
HPS (sodium)
82
Lampe High Pressure Metal Halide
71
LUX to PPF (µmol m-2 s-1)
Sun
0.0185
Fluorescent white lamp
0.0135
HPS (sodium)
0.0122
Lampe High Pressure Metal Halide
0.0141
Multiply PPF by the conversion factor to obtain Lux.
For example in the sunlight:
2000 µmol m-2 s-1 = 2000*54 = 108.000 Lux