hi... i've met with situations where i shoot photos of friends outdoors when its nighttime. i'm using a 430ex as my flash, with the tamron 17-50 2.8 as my lens. i usually try to go low on my ISO as well. i've tried using the "plastic cap-like cover" to diffuse my flash, but the effects on my subject's skintones still appear harsh. is there anyway i can shoot under such conditions (outdoors with no walls/ceilings to bounce, dark surroundings) and still obtain natural skin tones? pls advice me on whether the usage of diffusers like the lightspheres will help me achieve a natural skintone. thanks!