User ID wrote:
When you move in to fill the frame after reducing the group size down to half, you are doubling the image magnification ... and that costs two stops to maintain same DoF as was available at the longer distance.
Thaz how I chose f/5.6 based on your photo at f/2.8. But yes your f/4 might work cuz facial details will be larger and easier to see at the closer distance. But, for truly equal DoF, half the distance means two stops.
Got it. Good point.