animal lover /rat bastard
I don't believe that automatic anything would be wise when trying to compare photos. you need reliable calibrated results. probably should have taken a full bracketed set at a set white degree with a set exposure and set iso at a set distance etc so you could compare apples to apples, otherwise the photos are useless.....
Before and after pictures are not good for "light level" comparison, because the automatic exposure re-adjusts, but well documented absence of shadows prior to downgrade and after downgrade and a well articulated presentation can go a long way in challenging claims of equivalency that while watts were reduced, it did so at the cost of cutting corners.