An epi-illuminator for a planar sample, said epi-illuminator comprising: a planar platform with a designated sample area thereon that contains said planar sample; LED line lights (21, 22, 23, 24) mounted above said planar platform when said planar platform is horizontal, with at least two said line lights (21, 22, 23, 24) positioned along, and parallel to, each of two opposing parallel sides (14, 15) of said sample area and an optical bandpass filter (35, 36) between each said line light (21, 22, 23, 24) and said sample area, each said line light (21, 22, 23, 24) arranged to produce, through said optical bandpass filter (35, 36), a wedge-shaped light beam intersecting said sample area at acute angles (37, 38) and spanning said sample area in a direction transverse to said line lights (21, 22, 23, 24), with line lights (21, 22, 23, 24) on opposing sides (14, 15) of said sample area complementing each other to produce a combined illumination of said sample area that is substantially uniform in intensity along said transverse direction, wherein each of said line lights (21, 22, 23, 24) comprises LEDs with non-uniform spacing to avoid decreases in light intensity at outer ends of uniformly spaced line lights (21, 22, 23, 24), and wherein said non-uniform spacing decreases towards said outer ends of said line lights (21, 22, 23, 24); and a gap (25, 26) separating said two line lights (21, 22, 23, 24) along each of said parallel sides (14, 15) of said sample area, said gap (25, 26) being of a width sufficient to produce a combined illumination of said sample area from said line lights (21, 22, 23, 24) that is substantially uniform in intensity along a direction parallel to said line lights (21, 22, 23, 24). a planar platform with a designated sample area thereon that contains said planar sample; LED line lights (21, 22, 23, 24) mounted above said planar platform when said planar platform is horizontal, with at least two said line lights (21, 22, 23, 24) positioned along, and parallel to, each of two opposing parallel sides (14, 15) of said sample area and an optical bandpass filter (35, 36) between each said line light (21, 22, 23, 24) and said sample area, each said line light (21, 22, 23, 24) arranged to produce, through said optical bandpass filter (35, 36), a wedge-shaped light beam intersecting said sample area at acute angles (37, 38) and spanning said sample area in a direction transverse to said line lights (21, 22, 23, 24), with line lights (21, 22, 23, 24) on opposing sides (14, 15) of said sample area complementing each other to produce a combined illumination of said sample area that is substantially uniform in intensity along said transverse direction, wherein each of said line lights (21, 22, 23, 24) comprises LEDs with non-uniform spacing to avoid decreases in light intensity at outer ends of uniformly spaced line lights (21, 22, 23, 24), and wherein said non-uniform spacing decreases towards said outer ends of said line lights (21, 22, 23, 24); and a gap (25, 26) separating said two line lights (21, 22, 23, 24) along each of said parallel sides (14, 15) of said sample area, said gap (25, 26) being of a width sufficient to produce a combined illumination of said sample area from said line lights (21, 22, 23, 24) that is substantially uniform in intensity along a direction parallel to said line lights (21, 22, 23, 24).