Fill Flash--non-TTL autoflash with adjustable power:

        1. Set camera to exposure for background, keeping shutter
           speed at or below flash sync speed. Note the aperature
           setting.

        2. Set the aperature setting on the flash as follows:

           for one-half flash power, set it one stop open;
           for one-third flash power, set it a stop-and-a-half open;
           for one-quarter flash power, set it two stops open.

           Leave camera settings as they were.

        If necessary, change shutter speed and aperature to make
        available the aperatures used by the flash.

Hints by Art Ketchum:

	In bright sun, anytime in the day you can take great 
	fill flash images. Start by having your	subject face
	away from the sun. Do not let the sun light the face, 
	use the Sun to create your hairlight or backlight. 
	Use the incident dome on your meter to read the light 
	falling on the back of your subjects head, point the 
	dome directly at the sun or where the strongest light
	is coming from. On a bright sunny day , typically with 
	100 ISO film, your meter will probably read about 1/125 
	sec at F:11. Now set your camera on manual at 1/125th 
	sec and open the lens by one stop to F:8. Set your on 
	camera flash on automatic but use the F:8 setting on 
	your flash. You	will get perfect fill flash images as 
	long as you do not let the sun fall on the subjects 
	face, and you must set your camera on manual, this 
	will not work on Program or Automatic.

	from "Lighting for the 21st Century" at
	<http://www.photo-seminars.com/Seminars/LiteTwenty/LightCentury.htm>