Digital Camera Cheat Sheet

  • Shorter Focal Length = Wider Angle of View = More of the scene = Zoomed Out
  • Longer Focal Length = Narrower Field of View = Less of the scene = Zoomed In
  • Shutter Speed = How fast shutter closes limiting how much time the sensor is exposed to the scene
  • Shutter speeds described in seconds; faster shutter speed = fewer seconds
  • Use shutter speeds of 1/60 seconds or faster if doing hand held photography, else camera shake is visible; shake reduction or image stabilization feature of camera helps with this
  • For shutter speeds slower than 1/60 seconds, use a tripod
  • Aperture is the hole through which light travels to hit the sensor
  • Aperture size controls how much light hits the sensor — small aperture = less light; large aperture = more light
  • Aperture size also controls depth of field — small aperture = more depth of field; large aperture = less depth of field (large aperture results in only the focussed parts of the image being sharp while other parts are blurred; small aperture results in more parts of the image being sharp)
  • Aperture is mentioned as a f-number (e.g. f/1.4, f/2, f/8); f-number is also called f-stop; the number to the right of the slash is the actual f-number; f/1.4 is a small f-number and f/8 is a larger f-number
  • A f-number is the ratio of the focal length to the aperture diameter
  • Larger f-number = smaller aperture = less light = more depth of field; smaller f-number = larger aperture = more light = less depth of field (use larger apertures for macro shots and bokeh)
  • In general if you double the f-number (reduce the aperture and thus the amount of light hitting the sensor), you need to reduce the shutter speed by a factor of 4 (to compensate for the lesser amount of light due to smaller aperture)
  • ISO is a measure of sensitivity of the sensor to light
  • Lower ISO means sensor is not that sensitive; higher ISO means sensor is a lot more sensitive
  • Mostly use lower ISO (100, 200)
  • In low light conditions (night time; darkness) it helps to use higher ISO
  • But typically cameras don’t deal with the extra sensitivity at higher ISO very well and can result in blocky/smudgy ┬áimages
  • Shutter speed, ISO and aperture size work in tandem to control the amount of light that the sensor is exposed to (exposure)
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