Exposure, depth of field, ND filters, hyperfocal distance, flash power, focus stacking and print size — solved for you.
Solve for aperture, shutter speed or ISO given the other two and a target exposure value.
Focal length, aperture, focus distance and sensor format → near/far sharp limits and total DoF.
Base shutter speed + filter strength → the adjusted shutter speed with the filter on.
Focal length, aperture and sensor format → hyperfocal distance and the resulting sharp range.
Guide number, distance and aperture — solve for any one given the other two.
Focal length, aperture, sensor and near/far points → the number of frames and the focus distance for each.
Pixels to inches or cm at any DPI, and back — plus the largest sharp print your file can make.