Handholding is one of the most widely used methods of photography. The other being using a tripod. In general everyday photography, handholding is the oft used method. Say your kid is playing with the dog in the backyard. You decide to shoot some funny moments and reach for your DSLR. Setting it to a lower ISO (ISO 100 or less), considering it is a bright day, and a shutter speed of 1/1000 (or using basically the built-in metering system to take charge) you shoot several pictures. In this situation it is rare you would also reach for your tripod. Again, when shooting wedding photographs or for that matter even wildlife photography, a tripod may not always be at hand or feasible to use. Handholding capability would mean the ability to hold a camera steady by hand while shooting pictures so that there are no visible camera shake in the pictures resulting in softer final results. In this case if the subjects are steady (at times that could be difficult to expect) one can get great results. There would not be any camera shake resulting in blurry (soft) images. However when you’re shooting indoors or in dark conditions, the metering system automatically adjusts the shutter speed to something such as 1/10th of a second or even slower, to compensate for the lack of light. In such situations it becomes difficult to shoot images handholding the camera and a softer image with visible blur is the result. Generally photographers find it difficult to hand hold a shot which has an exposure time (shutter speed) of less than 1/30th of a second.
As a general rule of thumb, shutter speeds should match that of the focal length to eliminate camera shake. That means if you’re using a 55-200mm lens setting it to its longest focal length, a shutter speed of minimum 1/200th of a second is necessary so that there are no camera shake. This is however applicable for stationary subjects such as when shooting distant monuments, statues, specific features of an architecture that one cannot hope to reach close enough to shoot using wide angle. This is not applicable for subjects which are moving; say a child or a pet or even a bird that is perched at 500 yards from you. At such situations one needs to increase the shutter speed even further to “freeze” the moment. Ideally the shutter speed should be 1/400th or 1/500th of a second, considering that the foal length does not change.
Together with focal length another three factors can also determine your ability to handhold a shot. First is the aperture. Wider apertures automatically accommodates for a faster shutter speed. At wide apertures the lens allows for more light to reach the sensor. Thus one does not need a longer shutter speed. However there is a catch. Since wider aperture is associated with a narrow sharp focus area (usually the center of the lens) the whole image is not sharp from corner to corner.
The second factor that determines your ability to shoot while handholding the camera is your shooting posture and ability to hold still. Steady hands need some techniques and one of them is holding the elbows together for additional support when shooting. Another way is to hold your breathe till the exposure is done. Exhale before you press the shutter release and wait until the exposure is done till you breathe again. This can dramatically improve image sharpness.
Third is the image stabilization system. Both Nikon and Canon (the two top camera makers) have their own image stabilization systems. Canon calls it IS (Image Stabilization) and Nikon names it VR (Vibration Reduction). They both do the same, correcting for camera shake due to movement of the hand while handholding or due to wind gusts. Both can stabilize a frame which results in up to four stops of increased shutter speeds. However none of them can compensate for a subject that moves during the shoot or when you’re trying to shoot from an unstable or shaking base. They can only clear out so much of camera shake.