Aperture for us visual learners. A large aperture allows a lot more light to fall onto the sensor, and when this happens you have the freedom of using a faster shutter speed. A slow shutter speed has been used in this case so the final image is overexposed and unsuccessful. This is a mistake which must be corrected by using a faster shutter speed.
Example of illumination using a direct 180cm translucent umbrella (Butterfly technique) and a translucent panel beneath the face of the subject. Glow effect on the left of the image created in post-production. Nikon D3 + Nikon SU-800, 3 Nikon SB-910 flash heads, Nikkor 70-200mm VRII f2.8G, 1/125sec@ f 2.8, ISO 400, Cloudy WB. Model: Emanuela.