The recommendation considers that the HDTV studio standard must be harmonised with those of current and developing television systems and with those of existing motion-picture film. In a review of current systems, a consensus was identified in specifications for opto/electronic conversion, picture characteristics, picture scanning characteristics, and signal format (both analogue and digital representations). Work is underway in the editing of national and CCIR-related documents to determine whether these consensus values may be affirmed in the next review of the individual documents. The values in Rec 709 are considered interim, and CCIR notes that continuing work is expected to define target parameters for future improved image rendition.