A lens is provided which is elongated along an axis so to accommodate a linear array of LEDs, the elongation of the lens resulting in a corresponding elongation of the beam output pattern; in practice, the axis of elongation may be oriented so to suit a target area or some portion thereof. A methodology is provided for use with said lens so to evaluate various factors such as droop, heat management, and light output for a given combination of light sources and luminaire design. Alternative designs of lens, as well as alternative optical devices, are also presented for use with said methodology.