=== Zed's Cafe v9 === - [53] :: Цифровое изображение :: Компьютерный форум Ru.Board

Вот для д200, но принцип тот-же (только там в базе 300 000 patterns):

Matrix metering is a system that divides the image area into pieces (the “matrix”) and analyzes the differences between them. The brightness pattern seen in the matrix is
compared against a Nikon-proprietary database of image patterns stored in the D200’s internal memory, and the exposure is set accordingly.
The D200 uses a dedicated 1005-cell CCD in the viewfinder to provide metering, ala the F5, D1 series, D2 series, and D70 cameras. The “brains” behind the matrix metering have been
significantly improved from the older bodies, however. Older versions of this metering system used a 30,000 pattern database to test against; the D200 (and D2 series) has ten
times that number of patterns to consult, plus there appear to be significant improvements in handling pure white and pure black. Nikon calls this new system 3D Color Matrix II.

If a D-type or G-type lens is used (with or without flash), matrix metering also takes into account the focus distance (the “3D” in the name) to help guess where the subject is and
what kind of shot you’re taking. Example: normally, the matrix meter discounts brightness in the upper half of the scene, as it thinks this is sky, and unimportant; however, if you’re using a wide angle lens and are focused near infinity, the camera thinks that you’re taking a landscape photo and doesn’t discount the sky exposure as much.

The matrix metering system relies on five key data points:
1. The overall brightness of the scene.
2. The differences in light measured across the 1005- pixel sensor data (i.e. the “patterns”).
3. The focus area that has been selected (which the camera assumes says something about where the “subject” is located).
4. Distance information from the lens.
5. The color (or colors) of the areas measured.

Модерирует : GoodCos13, xy, Maz
xy (29-05-2008 13:27): http://forum.ru-board.com/topic.cgi?forum=36&topic=1667#1	Версия для печати • Подписаться • Добавить в закладки
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