Home Cinema Insight | Understanding HDR
Understanding 4K And HDR In Today ’ s AV Environments
Ken Eagle , director of field training / technical sales at Atlona , provides his take on where we are with HDR and what installers need to know .
Atlona has a range of HDR compatible hardware to help installers prepare for wide spread adoption of the technology
Seeing is believing . So while we can talk to clients about HDR until we ’ re red-green-blue in the face , all it ’ s going to take to convince most people that HDR is worth all the fuss , is one good side-by-side demo . Yes , seeing is believing . After all , one way to think about HDR is that it is the key remaining qualitative difference between the rich , vivid images you see in a theatre release versus what you see in today ’ s high-end home theatres .
But we ’ re getting ahead of ourselves . It ’ s true that there ’ s already a lot of information out there about HDR , HDR displays and HDR content , but I ’ ll say it ’ s also true that there ’ s not enough out there ( yet ) that puts this information into a concise context for installers .
Before delving deeper , there is one question you ’ ll want to be prepared to answer : is HDR a fad ? After all , look at 3D ( ironically , many new TVs have eliminated 3D support in favour of HDR ).
While no one can say with certainty what ’ s going to succeed , it ’ s a pretty safe bet that HDR is going to be with us for a while . HDR represents a major advancement in displaying more accurate , more realistic and more vivid colour with differences that are clearly visible . So much so that viewers consistently chose HDR over non-HDR as the better picture , even when HDR content is shown on lower resolution displays .
Also , in terms of the range of colours it can render , HDR is already a standard feature of cinema and TV video cameras ; so while HDR content has so far been slow in coming to consumers , we can expect a gradual if not rapid increase .
So what exactly is HDR ?
To start , we ’ ll review some of the key specifications we need for background in understanding the improvements HDR brings , starting with 4K and Ultra HD .
Unfortunately , the terms 4K and UHD get used interchangeably . 4K is shorthand and technically refers to the digital cinema specification for displays measuring 4096 pixels wide by typically ( but not part of the spec ) 2160 pixels tall , creating an image area with an aspect ratio of 17:9 . This is a wider-format image than seen in the 16:9 ratio used as the basis for the 1920x1080 pixel area associated with HDTV .
While a wide , 4K 17:9 image ratio might be desirable for cinematic productions , displays designed for home entertainment , if designed to a 17:9 specification , would waste seven % of their pixel area when showing content shot for TV and other 16:9 formats . Scalers could resize the image to use the entire screen area , but would introduce undesirable if modest disproportion to the picture .
Ultra HD , or UHD , stems from a set of broadcast , telecomm and consumer electronics industry specifications for 4K and 8K digital TV , including a CTA ( Consumer Technology Association ) specification that Ultra HD displays provide an input for a minimum native signal resolution of 3840x2160 . This is twice the vertical and horizontal resolution as full HDTV , preserving the 16:9 aspect ratio while quadrupling the number of pixels used to render the picture compared to full HD ( roughly 8.3 million vs . 2.075 million pixels ).
10 | September 2016