Hi Gang,

In preparing for our test next week, we have noticed that there are different answers in regards to a 3:1 light ratio.

The London book states that a 3:1 ratio is a difference of 1.5 stops.

But, I have found other sources (my lighting class at CPW and other lectures attended this year) that state a 3:1 ratio is a one stop difference.

Can someone clear this up for me. Why are there two answers and which is the correct one for the sake of the PPA Certification test?