Using an op-amp for resistive sensors



I've been working on this project to design a simple LED nightlight using a photoresistor over the past couple of weeks and having initially went with using a single transistor to control the circuit I've finally decided to just use an op-amp instead. The main problems with the transistor configuration:

(1) No clear-cut transition from off to on. The LED gradually brightens, but controlling the range of resistances in an acceptable way is difficult.
(2) Wild variations in triggering due to...

Using an op-amp for resistive sensors