The LS-150 Luminance Meter (successor to the LS-100) is a highly accurate luminance meter that uses a newly designed sensor with a spectral response that more closely matches the V(λ) spectral luminous efficiency function of the human eye to provide measurement results that correlate well with visual evaluation. The LS-150 is compact, ergonomic, and extremely portable running off AA batteries. The LS-150 series uses a single lens reflex (SLR) optics system that provides users with several important capabilities. The SLR allows highly accurate targeting of light sources. Very small areas, even down to 1.3mm (when close-lens is used), can be measured accurately. Measurement areas at distances both long and short show up consistently in the viewfinder. This flexibility allows even those who have never used the instrument to gather precise measurement results.