What new mAs setting would be needed to maintain the same film density achieved with a technique of 4 mAs at 40 inches focus-to-film distance (FFD), if FFD is increased to 80 inches?

Question

Quizplus · Accepted Answer

As the distance is doubled (40 to 80 inches), the mAs needs to be quadrupled to maintain the same film density. Therefore, the required mAs would be 16 (4 x 4 = 16).

What New MAs Setting Would Be Needed to Maintain the Same