Those beautiful Impressionist realist landscapes that make you wish you lived in a place where, with once glance, you could look down on farms and streams, mountains and villages, may not be quite as realistic as they appear. The vast majority of such canvases, which are almost always painted as if the viewer (and the painter) are looking down from the heavens at the glorious lands below, actually tend to be impossible views, at least, if the artist is meant to be standing in one place as he paints. A new exhibition in Salford examines the varied reasons for such mild deceptions, which range from God complexes to public relations gimmickry to simple humor.