The first is a more rudimentary type of live preview that displays the overall framing on an electronic display and allows a preview of what the camera's sensor will detect before the photograph is taken. This can be particularly helpful when the lighting conditions are too dark for an optical viewfinder. This type of live preview is the "autogain/framing" live view type (or "framing priority display"). This requires traditional means of exposure determination requiring metering of the light coming through the lens, and interpreting the light intensity indication on an automatic light meter, and then adjusting exposure parameters for a desired effect.