---- What have you done to deal with digital image stabilization functions?
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The high-performance digital image stabilization system is built into the camera body.
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Digital Image Stabilization Editing Components
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The gyro sensor detects even the smallest shakes with high precision.
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Compensation for camera shake can be delivered from within either the camera body or the lens. We had many discussions over which of these methods we should use.
The original concepts behind the E System's design were the pursuit of optimum image quality and mobility. Attempts to compensate for camera shake on the lens side impose constraints on lens performance, making it impossible to pursue top quality images. Moreover, incorporating digital image stabilization capabilities into the lenses would inevitably make them larger, thus affecting mobility. However, integrating the digital image stabilization edits into the body avoids the issue of larger lenses while maintaining maximum lens performance. This means that digital image stabilization is possible with Olympus Zuiko Digital lenses. When considering the E System's development concept, integrating the image stabilization system into the camera body was fundamentally the best possible decision.
---- What was the methodology?
Compensating for camera shake requires actuators (motors) that can instantaneously track shaking. Olympus made use of the supersonic motor technology it developed for microscope stages. For the E-3, we developed an image stabilization system that shifts the image sensor by the equivalent of up to five shutter speed steps, compared with a maximum of four for the E-510.
Naturally, it's essential to detect camera shake the instant it occurs. The difficulty lies in the fact that vibrations arise within the camera body. The question was, how can we eliminate noise superimposed on the gyro sensor that measures camera shake? In fact, cushioning material eliminates any vibratory noise from inside or outside the camera body, and since the E-510, we have made a variety of improvements to ensure that the E-3 offers the world's best performance in this respect.
Other questions include just how much the camera shakes and the extent to which this shaking can be accurately measured. If the shaking requires the equivalent of one shutter speed step in compensation, it is not really a problem. But if shaking requiring compensation equivalent to four or five shutter speed stops is detected, the difficulty increases geometrically. Very high levels of tracking precision and speed are involved in detecting movement and counteracting it instantaneously. High dimensions are required for everything from the sensor to the drive system. All noise generated by everything that moves within the camera body, including the shutter, is a problem. Still, excessive efforts to eliminate noise have an impact in other areas. ...I reached the stage where I felt like urging them to try harder for another few shutter speed steps. He In fact, when we tackled the problem, it was incredibly difficult.
One of the biggest problems was where to attach the gyro for measuring camera shake. Kataoka-san and the other people in charge of mechanisms worked on it tenaciously and, using a measuring instrument capable of detecting sub-micron vibrations, sought out the optimal installation position by measuring the vibrations caused by the action of the quick return mirror and the shutter at every single point within the camera body. The positioning of the gyro is different in the E-510 and the E-3, primarily because differences in camera structure mean that the vibration points also change. In other words, the best methodology is a step-by-step approach. A single, decisive breakthrough is out of the question.
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Built-in camera body image stabilization mechanism
The unit comprising the SSWF and imaging sensor moves to compensate for camera shake based on information detected by the gyro sensor. Two supersonic motors operating along the vertical and horizontal axes shift the unit accurately in an instant.
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The shutter on the E-3 features a maximum speed of 1/8000 sec. and an X synch speed of 1/250 sec., so a substantial charge is needed to raise shutter blind speed. Since everything else is fast and moves vigorously, including the quick return mirror, the vibrations caused by shocks from the camera itself have to be caught by the gyro sensor.
If we think about it, we have realized digital image stabilization capabilities that is far ahead of any system implemented only on the lens side. It was worth the effort.
Any attempt to install a mechanism within the lens to compensate for camera shake puts considerable constraints on the optical design. If such lens groupings are not necessary, the total number of lenses can be kept down, resulting in smaller, more compact lens units. Naturally, prices can also be kept down.
Taking the overall view, resolving these issues properly on the camera body side is extremely helpful, especially from an optical performance perspective.
---- At what stage did you decide to use ultrasonic actuators?
We had them in mind as an option right from the start. After taking everything into consideration, from characteristics, operation and power consumption to cost, we judged that supersonic motors where the best option. We also called on the developers to take part. The E-3 is the fruit of "One Olympus".
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