Photography Cheat Sheet

Trying to get my head around my digital camera.
 

Aperture

• Def: the lens diaphragm opening; i.e. how large the shutter curtain opens
• Calibrated in f-numbers, a.k.a. f-stops
  • f22 (f/22),16 (f/16), f/11, f/8.0, f/5.6, f/4.0, f/2.8, f/2.0, f/1.8 etc.
  • indicate inverse size: f/22 is smallest, f/1.8 is biggest
• Effect: controls amount of light entering
  • each smaller step (moving towards f/1.8) lets twice the light in
• 2nd Effect: affects Depth of Field (DOF)
  • see section "Depth of Field"
• http://www.mir.com.my/rb/photography/fototech/apershutter/aperture.htm
• Note: actual f-number diameter is unique to the lens -
  e.g. wide-angle lens will open differently than narrower, to get same f-val

Shutter Speed

• How quickly the shutter opens and closes
• Effect: slower speed lets in more light
• Indicated as fraction of a second:
  1/8000, 1/4000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2, 1 or -1, -2 etc.
• Effect: Regulates amount of light allowed in
  • each slower speed allows double the light of the previous
• 2nd Effect: Can freeze or blur a photo

Exposure

• Exposure = Aperture + Shutter Speed
• Hence, to maintain same Exposure:
  increase in Aperture <=> decrease in Shutter Speed
  translates as: reduce f-stop <==> increase ASA speed
  also can say: f-stop towards f/1.8 <==> ASA speed towards 1/8000

Depth of Field (DOF)

• Def: the focus of close and far away objects
• Smaller aperture extends DOF
  • Deep DOF = everything is in focus = moving towards f/22
  • Shallow DOF = only close objects in focus = moving towards f/1.8
• Focal length of lens affects DOF
  • Wideangle have deeper DOF
    • hence good for scenery shots
  • Telefoto have shallower DOF
    • e.g. use larger aperture with telefoto to blur a background
  • Wideangle = 35mm; 50mm is standard; 80mm+ is Telefoto