Until now, most of the research in the field of high dynamic range (HDR) video has centred on the use of non-real-time graded images which have been adjusted to look correct on a known reference screen in a reference environment. For live television, without the luxury of grading, it is important that images captured directly by the camera look correct. So the HDR system's end-to-end opto-optic transfer function (OOTF), which maps the light captured at the camera sensor to the light output from the display, is of paramount importance. Furthermore, it is critical that the artistic intent of the video is preserved when rendered for the viewer with a different screen in a different viewing environment. The authors present results of two subjective tests. The first test determines the most suitable OOTF for a reference environment and display; the second test determines how this transfer function could be adjusted so the high dynamic range video signal can be displayed on a range of different brightness displays whilst maintaining artistic intent.