A type of flare occurring when the sun or other strong light source is included in the scene and a complex series of reflections among the lens surfaces causes a clearly defined reflection to appear in the image in a position symmetrically opposite the light source. This phenomenon is differentiated from flare by the term ghosting due to its ghost-like appearance. Ghost images caused by surface reflections in front of the aperture have the same shape as the aperture a ghost image caused by reflections behind the aperture appears as an out-of-focus area of light fogging. Since ghost images can also be caused by strong light sources outside the picture area, use of a hood or other shading device is recommended for blocking undesired light. Whether or not ghosting will actually occur when the picture is taken can be verified beforehand by looking through the viewfinder and using the camera s depth-of-field check function to close down the lens to the actual aperture to be used during exposure.canonglossaryeu
In time (or long) exposure photography, an object that is only partially recorded on the film and therefore has a translucent, ghost-like appearance. Ghosting also occurs when using electronic flash at a slow shutter speed, and a second image is captured on the film by ambient light. Some people also refer to flare as a ghost image.
Sometimes it is important to indicate that a horizontal edge is indeed horizontal. But the edge has no corresponding edge with which to make a normal stem. In this case a special hint is used with a width of -20 (or -21). A ghost hint must lie entirely within a glyph. If it is at the top of a contour use a width of -20, if at the bottom use -21. Ghost hints should also lie within BlueZones.(The spec also mentions vertical ghost hints, but as there are no vertical bluezones it is not clear how these should be used).
A double image that results from using flash in relatively bright light at a low shutter speed. The two images, one from the ambient light and a second from the flash, do not perfectly coincide.
Bright spots of light,often taking the shape of the aperture, which appear in the camera viewfinder orin the final photograph when a lens is pointed at a bright light like the sun; controllablethrough the use of multilayer coating of the lens elements.