Olympus IS-1 manual Measuring the amount of light, Light metering, Spot metering

Measuring the amount of light

Light metering

Light metering refers to measuring the brightness of certain parts of a picture. The IS -1 employs three meterings: (1) ESP light metering, (2) center- weighted average light metering, and (3) spot

metering. According to your photographic

purpose, the IS-1 allows you to select that which is the most suitable.

At the same time, the IS-1 uses TTL (through the lens) light metering to automatically measure the light that enters the lens. This allows you to obtain very accurate light metering without any influence due to distance changes between the subject and the camera.

ESP (Electro Selective Pattern) light metering (Exposure mode P)

ESP light metering measures the central portion and peripheral portion of the frame separately. In doing so, the camera determines the proper exposure. The calculation processing program itself is based on trial and error data to properly compensate for backlighting. ESP light metering takes place automatically while in P (Program) mode.

Center-weighted average light metering Center-weighted average light metering is the most widely used light metering system (Fig. A). This system measures light within a wide range

with special emphasis on conditions in the center of the picture. When in A (Aperture-preferred) or M (Manual) mode, this light metering system

is automatically activated. Providing that differing contrast between brightness and darkness in the rest of the frame is not too

extreme (a portrait with an extremely bright background for example) the system provides excellent results.

Spot metering

Spot metering (Fig. B) measures the brightness in the central section of the frame only. Because this metering system calculates the correct exposure of one point, it is convenient when the subject is backlit or there is strong contrast in the picture. When shooting a subject in front of an extremely bright background, you should spot meter the subjects face. To make white objects look very white, use spot metering and then operate exposure compensation button in the (+) direction.

To make black objects look very black, use spot metering and then operate the exposure compensation button in the (-) direction.

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