well, the range will be approximately the same. what changes is the curve of the signal. with the fixed resitor to VDD and your LDR you are forming a voltage divider. if you lower the resistance of the fixed resistor, the signal will stay longer near VDD, will hit half VDD when the LDR is equal to the fixed resistor and will go to zero when the LDR resistance approaches zero ohm. if you make the fixed resistor higher in value, the VDD/2 point will be reached much earlier and more of the time is spent in the lower half. you can also try to make the fixed resitor 100k for example