Light and lenses: exposure, f-stops, depth of field, hyperfocal distance and image resolution
Aperture f-number is focal length divided by aperture diameter.
Combines aperture and shutter speed into one exposure figure.
Range of distances that appear acceptably sharp.
Focus distance that keeps everything from H/2 to infinity sharp.
Image magnification from focal length and subject distance.
Field of view from sensor size and focal length.
Focal length on a crop sensor expressed in full-frame terms.
Real-world size of one pixel in aerial/drone imagery.
Total pixels of an image in millions.
Smallest resolvable spot size set by diffraction at aperture N.
Relates flash power, aperture and subject distance.
Aperture, shutter and ISO trade off to keep exposure constant.
Relates focal length to object and image distances.
Blur streak length from subject speed and shutter time.
Pixels per inch when a photo is printed at a given width.