IEC 62977-3-4:2023 specifies the standard evaluation methods for determining the optical characteristics of HDR electronic display modules and systems. These methods apply to emissive and transmissive direct-view displays that render real 2D images on a flat panel or on a curved panel with a local radius of curvature larger than 1 500 mm. This document evaluates the optical characteristics of these displays under darkroom conditions. This document applies to the testing of display performance in response to HDR digital input signals that are absolute luminance encoded such as the HDR signal comprising RGB component values of Recommendation ITU-R BT.2020 colorimetry with SMPTE ST 2084 PQ luminance encoding and SMPTE ST 2086 metadata.