Speedlight test fire output vs camera fire output

Discussion in 'Lighting Equipment' started by iversonwhite, Jun 1, 2012.

  1. Using a P67II, and a flash meter with my Pentax AF-540fgz set to manual at 1/8 power on a light stand. When I do a test fire from the flash the meter reads f/5.6, when I fire from the camera via cable the meter reads f/6.3. The light stand didn't move and shutter speed didn't change. Can anyone explain? Thanks.
    IW
     
  2. Is anything about where you're placing your body when you meter from each position, what clothes you're wearing, etc., change how much light blocked/reflected, etc? I've had situations where whether or not I turn my face away - as I hold the meter - makes a stop's worth of difference in some lighting situations, as the meter sees it. That's what I get for having a large, lilly-white face!
     
  3. Thanks, Matt. I did a test and you were right. I must have been blocking some window light when test firing.
     
  4. Hey, I'm glad it was something that straightforward (because, you know, sometime it just ain't!). Unless there'a a bright floor or low reflectors involved, I've taken to doing most of my metering by crouching low and holding the meter up near the object/subject in question. Been burned several times by blocking/reflecting certain paths from a given light source to the scene, or just altering the way things bounce around. Good luck with your project!
     

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