when shooting outdoors on a sunny day using the sun as your main light source, normally we will get a very high contrast images.
cases-1: the background is great, but the model or object is little bit unbalance in brightness.
or object is good exposed, but the background is overbright.
cases-2: the shadows (example: shadow of nose or chin of the model or object) are look much darker than what it should be.
to encounter this matter, we use a technique called fill flash (or fill in flash). most of the latest production of flashs or speedlights have a setting for doing balanced fill flash (TTL BL) automatically. just set your flash to TTL BL, done.
to do fill flash manually, follow this steps. in this case i use my nikon SB-800 as reference. please adjust the concept into your own flash light.
• position your model or object under the sun lighting, however you like.
tips: when shooting a portrait, avoid the direct sun light to their eyes, this causes them to squint.
• use the camera's light meter to determine the correct exposure.
tips: a typical exposure for sunny day at iso 100 is f/16 at 1/125 second.
• determine the proper exposure for your flash.
use formula aperture = flash GN /distance
• set the flash exposure at 1/3 to 2/3 of a stop...