Camera shake is one of the significant factors affecting the quality of footage. Before the image stabilizer appeared, photography was only possible using a tripod. The only way to guarantee an excellent result. However, very often the use of a tripod deprives us of mobility and efficiency. Canon has developed a unique optical stabilization system of its kind to circumvent this limitation.
It is worth noting that gyroscopes are used in such a system, but they are quite tiny, and are used exclusively as sensors for fixing the movement of the lens, there are no massive rotating metal pancakes, coupled with the use of a huge battery and an electric motor for torsion. It is believed that such devices require a large amount of energy, but this is fundamentally not true. Of course, if it works for hours, then energy consumption will be noticeable.
Image Stabilizer: How It Works
Let's look at the most important points regarding the operation of the device. The image stabilizer shifts the objective lenses in a plane parallel to the film. If the lens moves due to shaking, the light rays from it move from their positions relative to the optical axis, which becomes the cause of the appearance of a blurred image. If you shift the stabilization lenses in a plane that is perpendicular to the plane of the film, within the limits necessary to compensate for the movement of the lens, it is quite possible to achieve an effect when the rays that reach the plane of the film remain practically stationary. In this case, the center of the image shifts down the film. If a group of stabilization lenses is shifted in the vertical direction, then the rays that are intended to form the image are refracted, after which the center of the image is in the center of the frame. Such parasitic movements occur in both directions, so the lenses can also move in both directions, perpendicular to the axis of the lens and parallel to the plane of the film.
The image stabilizer is not only the movement of the lenses. Any movement of the camera must be detected by two gyroscopic sensors. They determine the angle and speed of camera shake, which is typical of situations when shooting is carried out with hands. Sensors are located in a special unit that allows you to protect them from errors associated with the operation of the shutter or the reaction to the movement of the mirror.
The lenses of the stabilization unit have a direct drive from the core. Such a device is small, lightweight, consumes a small amount of energy, its response time is very short. The optical image stabilizer is very efficiently able to compensate for vibrations with a frequency of 0.5-20 Hz.
You can step by step schedule the operation of the device:
- when the shutter button is pressed incompletely, a group of stabilization lenses and gyroscopic sensors are activated to determine camera movement;
- sensors determine the angle and speed of vibration, after which the information enters the microcomputer;
- this information is processed by the microcomputer into commands for controlling the stabilization device, after which they are transmitted;
- the image stabilizer shifts the group of lenses perpendicular to the axis;
- during such a shift, the sensors process the information, and then transmit it to the microcomputer;
- the microcomputer compares the control signals with the signals from the detection device, monitoring the feedback received. This increases the degree of accuracy in the work of a group of stabilization lenses.
Excellent stabilizer performance can be seen with the Canon DM-XL1.