Increasing Image Stability
Image stabilization (IS) is not just one technique but a variety of solutions used by manufacturers to reduce shake and movement when using certain products---hand held cameras, still cameras, binoculars, video cams and telescopes. Shake and movement can originate in the user of the equipment but also from external causes such as vibration from inside a moving vehicle or building shake from exterior traffic or external events. Using an image stabilization setting or a lens that contains a stabilization mechanism, counters the effect and makes the images being viewed or recorded sharper. Image stabilization mechanisms go by many names---vibration reduction, shake reduction, steady shot, vibration compensation and optical stabilization are a few.
Optical Stabilization
Optical stabilization is found in the zoom and telephoto lenses of binoculars, digital video cameras and SLR cameras. Zoom and telephoto lenses are typically long and weigh more than other lenses, which means the user has to have a very steady hand to hold the weight and get a sharp shot. Most optical image stabilization techniques involve an optical sensor that detects movement. There is generally a sensor for detecting horizontal movement and another for detecting vertical movement. The sensors work to stabilize the image projected into the camera lens. Some stabilization systems contain tiny gyro sensors that sense overall angles of movement. Through feedback, they adjust the system and correct movement in the image. Optical stabilization mechanisms can add more weight to the lens.
Digital Stabilization
Digital stabilization happens within the camera body and not the lens. This means any lens used benefits from the stabilization technology. The sensors don't work to change the lens but instead to manage the body and correct shake. Servos (tiny motors) continually move the sensor to compensate for movement, like a balancing act. These types of stabilizers would work in video cameras and binoculars as well as SLR and digital cameras. Digital cameras and digital video cams work by using the pixels not included in the frame of the picture to compensate.
Specialty Stabilization
Special situations call for special stabilization techniques. Some video cameras offer a secondary stabilization mode called one direction stabilization. This technique provides stabilization for panning shots, which follow a path from point A to point B and then stop. Another way of dealing with unwanted movement in video cameras is by using isolation. The Steadicam is a harness system that removes the video camera from direct contact with the camera persons body. It comes equipped with a harness, a camera boom and a counter weight.
Tags: video cameras, cameras binoculars, digital video, sensors work, stabilization mechanisms, stabilization techniques