[tfiorda]

If you maintain the rule - 1/focal length * 1.6(for the sensor factor) = shutter speed - you will have excellent results handholding your camera with any lens. If the light goes too low, increase the ISO to maintain this rule. IS gives you the ability to slow the shutter 2-3 stops below this allowing some of the steadiest photogs the ability to take a long lens down to around 1/60th of a second, or slower, shutter speed and still handhold.

HTH,

Tony...