Hi!
The value of the LDR depends on the value of the resistor used along with it in the circuit. So if you use a resistor having higher resistance then we will need more darkness to get that fluctuation in the LDR readings / values desired.
You can check my answer here, it also has a video link for getting more insight on how the LDR works with different resistors used along with it and its sensitivity : Plant monitoring project
Hope this helps!
Good Luck! 