Center weighted sum point and matrix of mobile phone large dynamic range exposure measurement.

What you are talking about is the metering mode when the mobile phone takes pictures. The following are definitions of related terms:

1. Center-weighted average photometry: based on average photometry, the images at or near the center of the image are calculated according to different weighting coefficients, with the center weight as the largest, and the image gets smaller as it goes to the edge. The final value is the photometric value.

2. Spot metering: that is, only one point is metered, which is usually in the same position as the focus point (in fact, it is only a small area, not a complete point). The advantage of this method is that a certain point that the photographer thinks is correct, or the subject, can measure the light correctly according to the photographer's preference without interference from other nearby lights. For example, it is absolutely necessary to measure your face when you shoot backlight. When taking a photo with large light ratio (for example, half is in the sky and the other half is in the shadow), it is necessary to measure the part that you want to expose correctly. Because the metering point is not necessarily in the center of the composition, or it needs to be re-composed after metering, there is an AE lock, which can lock the exposure when metering is completed.

4. Matrix photometry: Evaluation photometry is the same concept. It is the result of vertical and horizontal division of 64 or 128 areas in the picture. According to the average gray level 18%, it is considered as correct exposure, and the aperture and shutter speed are given. Another way of saying this is the central key average metering, which takes the central area as the main metering basis and then averages it to other areas.

The advantage of this method is that it is easy to get a balanced picture, and the histogram of the whole picture is balanced, and there will be no local highlight explosion.

The disadvantage of matrix photometry is that it can't meet many conditions, such as shadow, backlight and so on.

5. Dynamic range: indicates the range from "darkest" to "brightest" contained in the image. The larger the dynamic range, the richer the levels that can be expressed and the wider the color space.

Wide dynamic range, that is to say, its dynamic range is wider and the color space that can be photographed is wider.

In a word, it means that your mobile phone has a variety of metering modes and a wide dynamic range shooting capability. Hehe, it's the first time I heard that there are so many metering modes in mobile phones. It seems that this mobile phone can compete with the camera.