During a summer in Spain, Eric Isenburger saw bullfights in Seville, and from those scenes of dramatic color came a series of paintings, two of which are shown on this page. Isenburger's tribute to the fiercely handsome animal who pits his wits and strength against a man's skill is evident in the painting at right. The bull is shown as a stately creature bathed in a kaleidoscopic aura of brilliant light and color. Below, in Afternoon in Sevilla, is the tense dance of the snorting bull and pirouetting matador. German-born Eric Isenburger came to the U.S. 20 years ago, is a citizen. Last year he was named a National Academician, and this year he is visiting professor of art at Mary Washington College, Virginia.