I've been asked to take a picture of my church (the people, not the building we meet in). They're renting a lift I can use to get adequate height to fit all ~250 people into the frame, but I'm kind of puzzled on what settings to use to ensure the sharpest posible image.
I'll be shooting with a Canon Digital Rebel T5/1200D with the wonderful EF-S 17-55mm f/2.8 lens. I've rented the lens once before and was astounded by its sharp images--definitely L-grade glass, even captured by the cheapest Canon DSLR.
The print will be small, probably no larger than a 17"x11", so I'm not worried about my Canon 1200D's 18MP resolution not being up to the task.
Given the size of the courtyard and previous years' examples, I'm assuming people will be standing in a group between 25 and 40 feet deep. I haven't been able to drag out a ladder and frame the scene, so I'm not sure what focal length I'll be using, but suspect it to be around 25-30mm to fit the sides of the crowd in.
I'm having trouble deciding, using the depth-of-field calculator, whether I need to use f/11 or can get away with f/8 (or even f/5.6!?) to keep everyone's faces reasonably focused, but work around the diffraction caused by 18MP squeezed onto an APS-C sensor. It seems that this is the only feasible option and that focus stacking a crowd would be nearly impossible.
Does anyone have experience with shots like these? Do I try my best to calculate it ahead of time, then do some quick variations the morning of and take the best result? Is getting as far away from the front of the group as possible and using the longest-possible focal length the easiest approach?