F-stop (also written as f/number or f-number) is how we describe the size of the aperture opening in a camera lens. It might seem backward at first: lower f-stop numbers mean a wider opening, and higher f-stop numbers mean a smaller opening.

For example:

  • f/1.8 = wide opening = more light, shallower depth of field
  • f/11 = narrow opening = less light, deeper depth of field

Each full stop of light either halves or doubles the amount of light entering the lens. The common full f-stops are:
f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22

Why It Matters

  • F-stop affects brightness (exposure) and focus depth
  • Lower f-stops give blurry backgrounds and brighter images
  • Higher f-stops give sharper landscapes but need more light

Tips

  • Don’t worry about memorizing the numbers at first — focus on how your photos look
  • Use Aperture Priority mode to control f-stop while letting your camera adjust the rest
  • Try different f-stops of the same subject to see how background blur changes

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