Future Tech Trends | Hybrid Log Gamma
because HLG ensures a high-quality UHD picture on just about any display ; as long as it supports the UHD resolution , of course .
The third major benefit of HLG was its ability to react more naturally to different viewing environments ; in direct contrast to the approach taken by Dolby Vision .
“ Not everyone sits in an ITU standard viewing environment at home . As the day proceeds and the lighting conditions change , so does the viewing experience . We wanted something that is fundamentally different to the Dolby approach , which is about absolute levels and our approach is about relative light , which is how television has worked for years .
“ In the Dolby system , effectively a value as captured at the camera should travel all the way through the system , and produce exactly the same light at the screen . That works well if you ’ re in the same display environment and there ’ s other data around that , that tells the screen how to adapt , but that ’ s not how TV generally works .
“ TV works by the camera iris being set by the camera operator to ensure the correct dynamic range in terms of light . The viewer then adjusts their viewing conditions to match . So , there ’ s quite a different interpretation as to how the light gets turned into electricity and the electricity gets turned back into light between the two systems .
“ Ours is just following years of practice in the TV industry , Dolby is taking a different approach in absolute light levels .”
Will an end-user notice the difference between the two HDR formats then ? Well , no .
“ In terms of performance . They ’ re absolutely the same . There ’ s no difference in the overall quality of the image . In fact , in some cases we do slightly better , in other cases Dolby do slightly better – but for all intents and purposes they have the equivalent performance .”
The difference comes from the workflow , with HLG more directly suited to the broadcast environment that the BBC requires . “ The Dolby system in our view – Dolby would disagree with this – is more suited to the cinema type of productions .”
So what does this all mean ? Well , while Dolby Vision and HDR 10 has enabled viewers to enjoy a wealth of HDR content from on-demand streaming services such as Netflix and Amazon Video , those wanting to watch live TV have been out of luck .
What exactly is HLG though ? “ If you imagine a camera on a bright day , then you ’ ve probably noticed how the scene can often react ,” Phil explains .
22 | March 2017 10th-11th May 2017 , Sandown Park , Surrey . Sponsored by