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Control of light is critical to heightening photography's expressive power. Nikon's light metering technologies are valued for their superior precision throughout the spectrum of lighting conditions. An engineer who has been developing these innovations for years offers insight into these technologies.
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MURAMATSU, Masaru |
Toward higher-precision exposure control.
Nikon technological innovation keeps leading the way.
Nikon metering technologies have a reputation for establishing standards of outstanding precision. Before going into details, can you give us a very brief history of these advances?
MURAMATSU, Masaru :
Our first metering system was an exposure meter using external sensors, for the Nikon F. In those days, other camera makers made external sensors link only with the shutter speed. But to optimize utility, Nikon devised a system of external sensors linked with both aperture and shutter speed. After mainstream metering technology moved to TTL (through the lens) systems, Nikon developed its “Center-weighted Metering” system, concentrating sensitivity in center frame, so images would not be overly influenced by the sky's condition, for example. Most cameras followed in featuring this system, which became a standard among TTL metering systems for a while. Nikon continued to use this system up to the introduction of the F3.
Then, for even greater precision, the company developed a five-segment matrix metering system, in which the frame was separated into five segments for measuring light intensity and a microcomputer in the camera calculated optimal exposure value. This feature, called “Automatic Multi-Pattern” metering for the Nikon FA, was the first of its kind. Then, for the F90, we advanced this system to use eight segment patterns. We're still on a never-ending quest to improve this metering system continually. For the F5, we developed a system using a CCD image sensor capable of capturing images by itself, as a metering sensor does. In our current camera lineup, we still feature the “3D-Color Matrix Metering” system using a “1,005-pixel RGB Sensor.”
Among the many exclusive technologies, the “1,005-pixel RGB Sensor” which you referred to seems particularly great. It has been the core element of the Nikon metering system for a while, from the introduction of the F5 up to the present, and is included in many film and digital SLR cameras. What advantages does it offer? What makes it a unique feature exclusive to Nikon?
The “1,005-pixel RGB sensor” features exclusive Nikon technologies and outstanding precision.
First of all, since it is an RGB sensor, it can measure color information as well as light intensity. Exposure should change according to color conditions, even when brightness remains constant. For example, reddish evening light and cloudy daylight could have the same brightness. So if the camera calculates exposure only by measuring light intensity, optimal exposure for both situations will be identical. The RGB sensor distinguishes scenes according to their colors, so true optimal exposure can be calculated for each situation. Among all film cameras, only Nikon film cameras have used this technology. A second advantage is the number of pixels, 1,005, which is far more pixels than any other camera maker's camera offers. The more pixels, the more detailed the subject information is for the camera to take advantage of. As a result, Nikon offers more precise exposure control.
I see. So the “1,005-pixel RGB sensor” achieves such high precision by measuring as many elements as possible, including information on colors and detail.
Exactly. But to handle this larger volume of information, a camera must have larger CPU capacity, so we always have to consider that balance. Increasing information for exposure control could mean sacrificing other information, so ultimately, we cannot simply use more and more pixels to create better images. Considering the need to balance camera functions overall, I can say that a 1,005-pixel count is ideal for the metering sensor.
