HOW SLOW CAN YOU HOLD?It depends on the weight and length of your lens, your biology and your camera-holding technique. In the workshops I teach, I frequently see cameras being held incorrectly. A DSLR camera is designed for the right hand to depress the shutter and the left hand to focus the lens and adjust the zoom, with the left palm supporting the base of the camera or lens—not facing out toward the subject of the photo. While holding the camera in the correct position, it's important to use the thumb and the index finger to focus and/or zoom the lens so it doesn't accidentally end up in your picture (which is prone to happen with a wide-angle lens).
Holding the camera in the correct way—and not creating a two-step process by palm-out focusing first, and then holding the camera—will help the photographer capture what Henri Cartier-Bresson called the "Decisive Moment," rather than capturing "The Moment After the Decisive Moment." If the photographer depresses the shutter holding the lens in the palm-out position, there's weakened support for the camera, which can cause camera shake.
Do the "Harris Mirror Test" (HMT) if you're like the millions of other photographers who suffer from BHT (Bad Holding Technique). Stand in front of a mirror and focus the lens with your left palm out. Doesn't that look amateurish? Then focus using the technique described above. Now you look like a pro! And more importantly, you have taken a major step toward photographing more like one by creating a solid platform for the camera and lens.
Now that you're holding the camera correctly, find out how slow of a shutter speed you can handhold before you get camera shake. Go outside and take a series of images of the same subject matter in open shade in the shutter-priority mode at 100 ISO using shutter speeds from 1/250 sec. down to 1/8 sec. On the LCD screen on the back of the camera, the results might look about the same, but the differences will be apparent when you look at them on your computer screen. Zoom in to the image and you can really see the point where sharpness falls off. The camera's settings are stored in the metadata of the image, so check it to see what shutter speeds worked and, just as importantly, which ones didn't.