Pronunciation: [ɡˈə͡ʊst ˈɪmɪd͡ʒ] (IPA) 
The word "ghost image" is spelt as /ɡəʊst ˈɪmɪdʒ/. In IPA transcription, the "o" in "ghost" is pronounced as a long "o" sound, while the "i" in "image" is pronounced with a short "i" sound. The "h" in "ghost" is silent, and the stress is on the first syllable of both words. This term refers to a faint and blurred secondary image that appears near the primary image, often caused by reflection or refraction.
A ghost image is a term commonly used in the field of optics and photography to refer to an indistinct or faint duplicate of an original image. It occurs as a result of unwanted light reflections or optical aberrations that can degrade the quality and clarity of a projected, captured or printed image.
In optics, a ghost image often arises when light reflects off surfaces within an optical system, such as lens elements or mirrors, causing light to scatter or refract in unintended directions. This reflection and scattering can lead to secondary images that appear as faint duplicates of the original, typically distorted or lacking in sharpness. Ghost images are often seen as faint, blurry replicas that appear near or alongside the primary image, potentially causing visual interference and reducing image contrast.
In photography, ghost images can result from the presence of bright light sources in the frame, inadequate lens coatings to reduce reflections, or even internal reflections within the camera. These unwanted secondary images can manifest as translucent or transparent replicas, giving the photograph an ethereal or supernatural aura. Ghost images can be distracting or unintended, potentially compromising the intended composition or undermining the clarity and integrity of the captured image.
Overall, ghost images are unwanted duplicates that are typically faint, distorted, or lacking definition. They are caused by reflection, scattering, or optical aberrations, and can occur in various optical systems, such as cameras or projectors.
The word "ghost" comes from the Old English word "gást" or "gāst", which referred to the spirit or soul of a deceased person. The term "image" traces its origins back to the Latin word "imago", meaning "a likeness" or "representation".
The combination of these two words, "ghost" and "image", gave rise to the term "ghost image". It refers to an optical phenomenon where a faint or secondary image appears alongside or superimposed on the primary image. This term is often used in photography, radiology, and other fields to describe the residual or double image that can be observed under certain conditions.
