View Poll Results: choose the correct formula

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  • GN2 = GN1*(ISO2/ISO1)

    2 33.33%
  • GN2 = SQUARE ROOT OF GN1*(ISO2/ISO1)

    3 50.00%
  • GN2 = GN1*(SQUARE ROOT OF ISO2/ISO1)

    1 16.67%
Results 1 to 7 of 7

Thread: Quitz of the day ( 4 )

  1. #1

    Default Quitz of the day ( 4 )

    If the guide number for an ISO 100 film is 84, the guide number for an ISO 800 film would be ??

  2. #2
    Senior Member
    Join Date
    Jan 2002
    Location
    UK
    Posts
    3,911

    Default

    Eh, your formulas all very complicated lah. I can tell you the answer and it doesn't involve more than simple multiplication. No division, brackets, curly brackets, squares, square roots, cubes, cube roots, etc...

  3. #3

    Default

    yah so cheem, guesstimate can already:


    84 x 1.4 x 1.4 x 1.4 = 230.

  4. #4

    Default

    what are you guys talking about ? what is a guide number?

  5. #5

    Default

    If the guide number for an ISO 100 film is 84, the guide number for an ISO 800 film would be ??

    answer is GN2 = GN1*(SQUARE ROOT OF ISO2/ISO1)

    :


    800/100 = 8

    square root of 8 = 2.83

    84*2.828 = 238

    GN2=200.

    the iso 800 guide number will be 238.
    Last edited by ninelives; 25th September 2002 at 07:11 PM.

  6. #6

    Default

    geeks. wonder if knowing this kinda info will help you guys score with babes.

  7. #7

    Default

    must give complicated quiz mah, else time passes very slow.

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