Low Relief:- Relief is a sculptural technique where the sculpted elements remain attached to a solid background of the same material. The term relief is from the Latin verb relevo, to raise. To create a sculpture in relief is to give the impression that the sculpted material has been raised above the background plane.[1] What is actually performed when a relief is cut in from a flat surface of stone (relief sculpture) or wood (relief carving) is a lowering of the field, leaving the unsculpted parts seemingly raised. The technique involves considerable chiselling away of the background, which is a time-consuming exercise. On the other hand, a relief saves forming the rear of a subject, and is less fragile and more securely fixed than a sculpture in the round, especially one of a standing figure where the ankles are a potential weak point, especially in stone. In other materials such as metal, clay, plaster stucco, ceramics or papier-mâché the form can be just added to or raised up from the background, and monumental bronze reliefs are made by casting.
There are different degrees of relief depending on the degree of projection of the sculpted form from the field, for which the Italian appellations are still sometimes used. The full range includes high relief (alto-rilievo, haut-relief),[2] where more than 50% of the depth is shown and there may be undercut areas, mid-relief (mezzo-rilievo), low-relief (basso-rilievo, or French: bas-relief /ˌbɑːrɪˈliːf/), and shallow-relief or rilievo schiacciato,[3] where the plane is only very slightly lower than the sculpted elements. There is also sunk relief, which was mainly restricted to Ancient Egypt (see below). However the distinction between high relief and low relief is the clearest and most important, and these two are generally the only terms used to discuss most work.
The definition of these terms is somewhat variable, and many works combine areas in more than one of them, sometimes sliding between them in a single figure; accordingly some writers prefer to avoid all distinctions.[4] The opposite of relief sculpture is counter-relief, intaglio, or cavo-rilievo,[5] where the form is cut into the field or background rather than rising from it; this is very rare in monumental sculpture. Hyphens may or may not be used in all these terms, though they are rarely seen in "sunk relief" and are usual in "bas-relief" and "counter-relief". Works in the technique are described as "in relief", and, especially in monumental sculpture, the work itself is "a relief".
From Shadow:- A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or a reverse projection of the object blocking the light.A point source of light casts only a simple shadow, called an "umbra". For a non-point or "extended" source of light, the shadow is divided into the umbra, penumbra and antumbra. The wider the light source, the more blurred the shadow becomes. If two penumbras overlap, the shadows appear to attract and merge. This is known as the Shadow Blister Effect.
The outlines of the shadow zones can be found by tracing the rays of light emitted by the outermost regions of the extended light source. The umbra region does not receive any direct light from any part of the light source, and is the darkest. A viewer located in the umbra region cannot directly see any part of the light source.
By contrast, the penumbra is illuminated by some parts of the light source, giving it an intermediate level of light intensity. A viewer located in the penumbra region will see the light source, but it is partially blocked by the object casting the shadow.
If there is more than one light source, there will be several shadows, with the overlapping parts darker, and various combinations of brightnesses or even colors. The more diffuse the lighting is, the softer and more indistinct the shadow outlines become, until they disappear. The lighting of an overcast sky produces few visible shadows.
The absence of diffusing atmospheric effects in the vacuum of outer space produces shadows that are stark and sharply delineated by high-contrast boundaries between high and dark.
For a person or object touching the surface where the shadow is projected (e.g. a person standing on the ground, or a pole in the ground) the shadows converge at the point of contact.
A shadow shows, apart from distortion, the same image as the silhouette when looking at the object from the sun-side, hence the mirror image of the silhouette seen from the other side.
