Bryan Peterson's Understanding Photography Field Guide

To exert full control over the shutter speed and aperture, use M mode. It allows you to use a shutter speed faster than 1/60 second and smaller apertures. This is critical because it allows you to use flash outdoors as a fill light.

a rule of thumb with 35mm film is to use a shutter speed that is the reciprocal of the focal length of the lens. For example, if you use a 100mm lens, you should set a minimum shutter speed of 1/100 second. This guideline does not account for Sony’s Steady-Shot feature (the default is [On]), which allows you to use longer shutter speeds.