1: Switch your camera to Shutter Priority mode by turning the mode dial to ‘S’ or on Canon models, ‘Tv’.
2: Choose a slower than normal shutter speed to blur the water. 1/30 is a good starting point.
3: Check your photo. If the water isn’t blurred enough, choose a slower shutter speed like 1/15 or 1/8. Note you may need a tripod or an anti-shake system to avoid camera shake – see below.
4: In shutter priority, your camera will work out the aperture setting for you. If the f-number starts flashing though, it means it can’t balance the shot. In this example, the exposure may be too long, so if your sensitivity (ISO) is already at the lowest number, you’ll have to choose a slightly quicker shutter speed until the f-number stops flashing. Alternatively wait until it gets darker, or consider using a neutral density filter, see below.
5: After taking your photo, remember to set the mode dial back to Auto or Program mode.
As you reduce the shutter speed, you become more susceptible to camera shake. People vary, but if you’re using a kit lens zoomed-out to wide angle without any kind of anti-shake, the slowest handheld exposure you’ll normally get away with is about 1/30. If you naturally shake, you may need at least 1/60, but if you’re very steady, then you may be ok at 1/15. If you zoom-in at all, you’ll need faster exposures to compensate for the greater magnification.
So when applying this technique to blur water, always hold your camera very steady. Tripods can provide a steady base, or alternatively cameras and lenses with anti-shake facilities can greatly help here – see below. If you are using a tripod, remember pressing the shutter release button can still wobble your shot. So always take the photo with either a shutter release cable or the self-timer to avoid all chance of shake.