Portrait photography is a picture of someones face and sometimes a background and the full body like when you take pictures with your family you would take family portraits for maybe christmas cards or special times when you family comes for dinner or a special occasion. It can relate to a profile view and silhouetting by a profile is like a picture of someones face but only seen on one side but it's still a picture of a face. Silhouetting is related because it is an image of an animal, person, or an object in a scene that represents a solid shape or singular color. All of it relates by a profile being a picture of someones side of their face, silhouetting being a picture of animals ,people , and sometimes objects but each of them mean a picture of a persons face.
Double exposures are created in photoshop by taking a couple pictures of textures and a profile of someones face and you use the dodge tool in photoshop to outline your face in white so you can make it into a multi exposure picture also so you can see texture in the background
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