Edward Comer bought a whole bunch of inexpensive light dependent resistors, and discovered that they were not exactly performing to specification. So to seperate the good and the bad, he concocted a few Arduino-controlled devices that shine an LED at various brightness levels, and log the value returned by the LDR under test. The data is sent to a PC via the serial/USB link and then recorded and can be analysed with various software.
If you need a light sensor, you can maintain constant reliable results with our LIGHT: light sensor module:
Our tiny light-sensor module uses the very-reliable TEMT6000 light sensor, which gives consistent and repeatable readings even between different units - unlike cheapie light-dependent resistors, which can vary dramatically in their sensitivity. So for reliable light sensing - look no further.