An analysis of around 1000 photos shot by professional photographers showed the distribution of the main focal point of these compositions. Using this information, the eleven AF points in the Olympus E-3 cover all of these areas.

The solution:
With the introduction of the Olympus E-3 D-SLR, a newly-developed AF system was presented that set new standards in terms of speed, precision and reliability. Together
with the ZUIKO DIGITAL ED 12-60mm SWD lens, the world’s fastest AF speeds in a D-SLR could be achieved with the highest levels of precision. Besides blisteringly-fast AF performance, photographers also benefit from a system that functions reliably across the whole gamut of photo situations including subject tracking.

How it works:

The autofocus sensor integrated in the Olympus E-3 is an 11-point twin cross type. It features dual sensing arrays on both vertical and horizontal axes at each point, arranged in a hound’s tooth pattern (sometimes also called a “half-pitch shifted” pattern) to ensure maximum precision and low-light efficiency. This effectively bestows the E-3 with 88 data points. The layout of the sensors was determined after analysing around a thousand professionally-shot photos for the distribution of the main subjects in the compositions and consultations with numerous photographers.	AF sensor unit	Cross section of the optical path
The eleven points selected provide the complete requisite coverage as indicated by this research. The dedicated AF data processing engine is paired with a newly-developed distancemeasuring algorithm which is streamlined to process data simultaneously. As a result, measurements and calculations deliver a maximum in speed and precision.
Further-more, due to the cross type design on all eleven sensors and a proprietary Olympus microsensing technology equally effective performance on both the vertical and horizontal axis is achieved. Subjects with little contrast or in low light are also focused accurately and quickly. Performance is improved by pixel multiplication technology to reach an impressive –2EV (total detection range from –2 to 19EV). To ensure highest precision under varying shooting conditions, a dedicated temperature sensor additionally compensates for changes in operating conditions.	AF sensor
The IC (integrated circuit) with high-speed distance computations and a new AF algorithm provide a high focusing speed even from an extremely defocused state. Moreover, communication speed between the body and lenses has been improved. From this, all types of Four Thirds lenses can benefit.

Hound’s tooth sensor layout A half pitch-shifted dual sensing array detects focal points more accurately than ordinal types. It combines each output from the sensing array to obtain exceptionally sharp output.

Photographers have the choice to precisely set the active target area and also choose from various target-selection cycles.

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