Photography

An accelerated test is a test of materials, such as pigments and paints, by artists.  The test is performed in a lab with certain equipment in order to simulate situations that will result in cracking, fading and other breakdowns that paintings are vulnerable to over a period of time.  Although accelerated tests do not exactly replicate normal effects aging because of their severity and concentrated forces, the tests are able to point out the resistance/lack of resistance that ingredients and materials may manifest when put under severe forces.  

A photograph that causes a positive image on a sheet of glass utilizing the wet plate collodion method.  It was first used in the 1850s in the United States.  The method was invented by Frederick Scott Archer but ambrotypes utilized the plate image not as a negative, but as a positive.  James Ambrose may be credited with coining the term "ambrotype"; he took out many patents in regards to the process.  

A still or moving picture comprised of two similar but different perspectives of the same subject matter in superimposed contrasting colors; the result, when seen through two similarly colored filters.  The anaglyph may also refer to a section of decoration or sculpture made into relief such as a boss/cameo.  It is different than a diaglyph which features depressed carvings/engravings.   

Cellulose acetate is derived from cellulose which is used in the processing of lacquers, plastics, photographic film and textile fibers.  Because it is less flammable that celluose nitrate, it is less dangerous to use in film.  Moreover, it does not yellow to the same degree as cellulose nitrate does in the daylight; however, cellulose acetate does not last as long, is not as hard and lacks other lacquer properties.  Permanent constructions or paintings should not use cellulosic products due to their instability.  

Limiting focus is a technique in which photographers and other artists can limit the area of their pictorial compositions that are in focus.  It is a method of simplification, helping the viewer to focus on exactly what the artist wishes the viewer to look at in a picture.  A typical example is a close-up of a flower with the background behind it being blurry.  This technique can be achieved in photography by using a wide aperature when taking a picture to limit the depth of field.  Everything that is not the main focus of the shot will be blurry.