Artificial lighting f-stop setting

Discussion in 'Lighting' started by Matt5791, Dec 15, 2005.

  1. Matt5791

    Matt5791 Subscriber

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    If someone says "I am setting this flash monoblock to f5.6" does this mean they are setting the output of the light to correspond to a setting of 5.6 on the camera lens?

    Sounds like a stupid question I suppose, but I have never used such equipment.

    any thoughts appreciated,

    Thanks,
    Matt
     
  2. rbarker

    rbarker Member

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    It's hard to say what they meant with the statement taken out of context. But, it sounds like the output of the unit is sufficient to shoot at f/5.6 with whatever film they are using, with the unit placed at some unknown distance from the subject.

    Most electronic "studio" flash units have a maximum output, usually measured (or, mis-measured) in watt seconds. Then, they have controls that allow the output to be reduced from maximum, either continuously or in steps that relate to quarter, half or full-stop reductions. The wrinkle is that the watt seconds metric is power consumption, not power output. Thus, as light-output efficiency varies, direct comparisons between brands is a little iffy.
     
  3. Nick Zentena

    Nick Zentena Member

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    My guess is they've set the light so the meter reads F/5.6. You might have one light set so it reads F/8 the other so it reads F/5.6.
     
  4. haris

    haris Guest

    Yes, he or she say that particular monoblock is set to give properly exposed image with lens aperture setting of f5.6. (of course for given ISO speed, and if not leaf shutter lens is used for X speed of shutter)
     
  5. Matt5791

    Matt5791 Subscriber

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    Thanks for the replies,

    Matt