Exposure Digital Function Metering

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Using the Reflected Light Exposure Meter

Reflected light exposure meters, in general, are not used to obtain a single correct exposure. They are normally used to make light readings of various parts of the subject, but the lighting around the subject can greatly affect the camera film (or CCD on a digital camera) due to the color and material of the subject, even under similar lighting conditions. As the metering range can be specified fairly precisely with spot exposure metering such as that provided on this camera, to capture the desired picture with a camera, you must meter the brightness at various points on the subject and then decide which value based on what standard to use in the camera settings. The following describes the common methods for using the exposure value metered with a reflected light exposure meter as a reference for making the appropriate photographic decisions.

Averaging Reading Method

This method is used to obtain the most suitable exposure value by averaging the brightest area (highlight) of the subject with the darkest area (shadows).

To use the Optio 750Z as an exposure metering with this method, first meter the highlight of the subject and then meter the shadows. As described in Step 6 on p.173, the first and second metered values (and those thereafter) are saved and then appear on the EV scale. The average of those values can be easily derived by using the four-way controller (45) to move the exposure value to the point exactly between the first and second values. This is the average of the two values. Because this method obtains the exposure of the intermediate level between the brightest and darkest areas of the subject, it is effective for capturing a well-rounded picture with balanced lighting. However, when the subject has a significant difference between the highlight and the shadows, it is recommended that you take at least three exposure readings, calculate the average and determine, yourself, which area of the composition represents the intermediate level. To obtain a fairly appropriate exposure value with a single metering, try placing a gray card with a reflectance of 18% perpendicular to the camera’s optical axis when taking readings.

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