Camera Field Cards explain the controls on your camera, one idea per card: what each letter on the mode dial does, how aperture, shutter speed, and ISO trade off, which shutter speed freezes motion, how to read a histogram, which focus and AF area mode to use, and more.
Each card is sized for a phone screen. Swipe through the included PDF, or save any of the 20 PNG images to your device's Photos app for quick reference in the field.