float lightValue1 = ls1.readNormalizedValue();
float lightValue2 = ls2.readNormalizedValue();

if(lightValue1 < maxLight*2) {
  maxLight = (maxLight * (1-alpha)) + lightValue1*alpha;
}
if(lightValue2 < maxLight*2) {
  maxLight = (maxLight * (1-alpha)) + lightValue2*alpha;
}
if(lightValue1 > minLight/2) {
  minLight = (minLight * (1-alpha)) + lightValue1*alpha;
}
if(lightValue2 > minLight/2) {
  minLight = (minLight * (1-alpha)) + lightValue2*alpha;
}
lightValue1 = normalize(lightValue1, maxLight, minLight);
lightValue2 = normalize(lightValue2, maxLight, minLight);