Although it is customary to make all subjective judgments of image quality from the reference monitor display, the infinite possibilities for monitor adjustments have hampered reviewers in exercising effective programme control, and have introduced many disparities and great confusion. The SMPTE Working Group on Studio Monitors, S17.28, is completing work on three specifications intended to make the monitor display follow a known electro-optic transfer function and permit a reliable evaluation of the programme image quality.