計算鏡頭焦距及標準全級光圈光闌面積

main.rb

focals = [20, 50, 85]

f_numbers = [1.4, 2, 2.8, 4, 5.6]

focals.each do |focal|

  puts "鏡頭焦距：#{focal}mm"
  puts ""

  f_numbers.each do |f|

    a = ((((focal/f)/2)**2)*3.14).round(2)

    printf "ƒ/%-5s 光闌面積 %-6s mm2\n", f, a
  end

  puts ""
  puts ""

end