Fill in flash

Discussion in 'Medium Format Cameras and Accessories' started by benjiboy, Sep 26, 2005.

  1. benjiboy

    benjiboy Subscriber

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    I would appreciate any advice you could give me guys on using flash for filling the shadows (synchro sunlight ) for outdoor portraits with between the lens shutters. I know the shutters will sync at any speed, but what is the best way to balance the flash with the ambient daylight ? I use a Mamiya C330Fs with 55, 80,135, 180mm lenses with a Metz 45CT1 flash which has 5 computer apertures and manual.

    I am trying to get the lighting right to achieve a 1:2 or 1:4 contrast ratio on the subject, and still retain a correctly exposed backgtound.
     
  2. David H. Bebbington

    David H. Bebbington Inactive

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    Set camera for correct exposure of directly lit background. Set flashgun to one stop LARGER than the stop you are actually using for 2:1 ratio or two stops LARGER for 4:1 fill (flashgun set to, for example, f8 outputs half as much light as when set to f11 for same film speed). As you are using leaf-shutter lenses, any speed can be used with electronic flash.

    Regards,

    David
     
  3. Blighty

    Blighty Subscriber

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    I use a couple of techniques for different lighting conditions. The one described above by David is the best one to use if you're shooting with the sun behind the subject. Simply meter on the background, transfer the reading to your C330 and then set your flash one stop wider (if your camera is set to f8, set your flash to f5.6). The other technique I use is for when the light is falling across the subject, one half in shadow the other in full sunlight. Take an incident reading towards the light source (the sun?) and set this on your camera. Again, set your flash one stop wider, as in the previous example. This gives you beautiful, well exposed highlights and also picks out the shadows.
     
  4. celeborn

    celeborn Member

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    Thanks for asking the question and thanks for the extremely useful answer.
     
  5. Bighead

    Bighead Member

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    I agree with everything above.. I usually set it 2 stops higher though... Just my personal preference... I may be compensating for something else I am not doing properly, but it works.
     
  6. Woolliscroft

    Woolliscroft Member

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    Me too. I find only leaving a one stop gap can look rather artificial. That said I might tend to slightly overexpose the lit parts of back lit subjects, to show that they are back lit. Only a fraction (third to half a stop), but somehow it looks more natural and it brings the filled area up a bit too.

    David.
     
  7. MikeS

    MikeS Member

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    Gee, I must be using outdated flash equipment. None of my flash equipment has any way of setting an f-stop on it. My newer stuff (Honeywell Strobonars) have either an on/off switch, or an off/m/a switch. My other flash stuff has no switches at all, just a socket to insert a flash bulb!

    So using these antique flashes, how would I go about doing this same scene?

    -Mike
     
  8. Blighty

    Blighty Subscriber

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    You calculate the F stop required for the flash -to-subject distance (say f5.6) then set your aperture to f8 and adjust the shutter speed to give a correct reading for the background.
     
  9. David H. Bebbington

    David H. Bebbington Inactive

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    Other replies are entirely correct for a totally manual flash, however the "off/m/a switch" suggests that this gun does have an automatic function (confirmation - is there a place on the gun to set film speed and read an aperture from a scale?) If so, you can persuade the gun to give a ratioed fill by setting a "wrong" film speed - if the flashgun "thinks" you are using ISO 200 film, whereas you're really using 100, it will give a flash one stop weaker than normal.

    A further factor with really old manual-only flashguns is that the guide numbers may well have been rather optimistic when new and won't have got more accurate with age.