may be pre-stored in the camera, and the processor can use that information to determine what is being photographed. Some cameras allow the option of locking exposure when autofocus is achieved. In other cameras the AF point is not used for exposure calculation, and in such cases it is common for metering to default to a central point in the viewfinder, using a pattern based on that area. There is considerable variation among different manufacturers how multi-zone metering is implemented–even in the model range of the same brand–and how much priority is given to the AF point itself. Some "Scene" modes, such as sunset, sports and night exposures also often affect the calculations of this metering pattern. Highlight-weighted metering Clipping is reduced by using a high resolution metering sensor and analyzing each area for washed-out ("blown") highlights or underexposed shadows. Although there are some similarities with multi-zone, matrix, or evaluative metering, this mode uses a high-resolution sensor for detailed detection and gives more weight to reduce clipping. See also Feathering Vignetting References External links Understanding Metering and Metering Modes Metering Modes and How Your Camera Meter Works Highlight-Weighted Metering: Technical Details and Use Nikon Camera features