Is it necessary to use flash for portrait photography?

Whether indoors or outdoors, 100% is necessary. Nikon user creative photography, fill the top lamp SB800\SB900-SB5000.

Attach flash' calendering' pictures and data:

File name light and shadow. The file extension of encoded image stored in jpeg file exchange format.

File size? 55K

Image size? 368 * 246 ?

Exif version? 0220

Manufacturer? Nikon company?

Camera model? Nikon D8 10?

Shooting date? 20 17:04:30 18:09:37

Shutter speed? 1/200 seconds

Aperture? F 1 1.0？

Focal length? 24 ?

ISO 100

Exposure compensation? 0.0

Maximum aperture? F2.8

Flash? Open?

Automatic white balance

Photometric method? Weighted photometry

Shooting procedure? Aperture priority

Shutter time? 7692

Lens? 14-24mm F2.8