In simple terms, the impressionist draws or paints what he or she sees - but quite often not what he is directly looking at. First and foremost the impressionist is striving for something the 17th century art critic Roger de Piles called the unity of effect.
At their most basic levels, drawing and painting are initially all about creating the correct shape in the correct place. On their own, neither a shape nor placement suffice. To be completely accurate, both must be correct.
The terms Impressionism and Impressionists normally refer to an art movement from the late nineteenth century, as well as to its adherents. Defining the qualities which make Impressionism impressionistic is a bit more difficult.
All too common among self-taught artists (as well as some trained ones) is a lack of edge variation in their work. Although the opposite also occurs, this error is most often made by representing all edges as being equally sharp. But to make an accurate representational statement you must use the full range of edges and this begins with finding the extremes: the sharpest sharp and softest soft.
Context is everything, or so the saying goes, and it's so familiar that it's easy to quickly skip past it. But stop and think about it for a minute. In any given scene all values are unconsciously perceived relative to every other value.
Mentioned before is the fact that Sight-Size is as useful for drawing all visual subjects as it is for cast drawing and portraiture. Why? Because it is the only arrangement which provides the eye of the painter with a one-to-one comparison between the subject and artwork.
During the late nineteenth and early twentieth centuries numerous artists and instructors wrote instructional manuals attempting to show the general populace how to draw. Many of those authors incorporated aspects of Sight-Size into their teaching. Edwin George Lutz, author of Practical Drawing, was one such popular arts teacher.
Although Sight-Size is most often discussed as an approach to portrait painting, Sight-Size is not just for portraiture. In fact, the first written use of the term relates to figure drawing.