EDR is a term with four distinct meanings across the display industry: a deprecated content standard (Dolby’s 2014 ‘Extended Dynamic Range’), a cinematic projection standard (Dolby’s ‘Enhanced Dynamic Range’), a technical implementation (Apple’s ‘Extended Dynamic Range’), and a perceptual model (‘Entertainment Dynamic Range’). This article clarifies these definitions to untangle the confusion.
EDR as a Cinematic Term: “Enhanced Dynamic Range”
Rasmus Larsen, founder of flatpanelshd, a website dedicated to TVs, media players, game consoles & the TV market, writes that EDR is used to differentiate between home theater – the only place where HDR can truly be experienced – and Dolby Cinema, which has a significantly restricted luminance capability when it comes to rendering highlights:
“In theaters, Dolby uses projectors that are not capable of reproducing HDR images, which is why industry members typically refer to Dolby Cinema as EDR (Enhanced Dynamic Range) rather than HDR (High Dynamic Range), which can only be experienced at home on displays such as OLED TVs or in a few theaters equipped with direct-view microLED displays.”
EDR as an Early Dolby Term: “Extended Dynamic Range” (2014)
In its 2014 whitepaper The Art of Better Pixels, Dolby Laboratories defined EDR (“Extended Dynamic Range”) as a term for video combining both High Dynamic Range (HDR) and Wide Color Gamut (WCG).
This definition was part of Dolby’s argument for moving beyond the limitations of CRT-based standards. The paper outlined the need for a system capable of a luminance range from 0 to 10,000 nits and the BT.2020 color gamut.
The work also introduced the Perceptual Quantizer (PQ) EOTF, which later became standardized as SMPTE ST 2084. In this context, EDR was the content standard and PQ was the transfer function to encode it.
EDR as a Tech Implementation: Apple’s “Extended Dynamic Range”
Meanwhile, Digit.in explains why Apple refers to its HDR technology as EDR and what the acronym stands for:
“EDR stands for Extended Dynamic Range and Apple uses the term in context with both HDR implementation and its HDR rendering technology… EDR is adaptive technology and it’s about rendering HDR in a way best suited to a particular display and best suited to a particular viewing environment.”
Why Apple’s Approach is Brilliant
Apple’s implementation of EDR is arguably the most user-centric and technically coherent model in the industry because it:
1. Prioritizes Ecosystem Consistency: It creates a unified, predictable experience across all Apple devices. An HDR video renders with the same intent on a MacBook, iPhone, and iPad. This is a monumental technical achievement.
2. Respects the User’s Environment: By being adaptive (considering ambient light, content, and display capabilities), it ensures the HDR experience is always tailored to what is actually perceptible to the viewer.
3. Seamlessly Blends SDR and HDR: The OS and UI remain in a comfortable, familiar SDR space, while HDR content extends from that foundation into higher luminance.
EDR as a Perceptual Model: “Entertainment Dynamic Range”
Lastly, in the publication Perceptual Design for High Dynamic Range Systems, EDR is defined as ‘entertainment dynamic range’ – the practicable luminance range for consumer media, situated between the steady-state and long-term-adaptation of the human visual system. It acknowledges that during media viewing, the HVS may not fully adapt to the brightest or darkest possible signals in every scene.
Summary:
EDR | Enhanced Dynamic Range | Dolby Cinema | A term for HDR-like contrast in projection, which is limited by projector luminance.
EDR | Extended Dynamic Range (Dolby 2014) | A since-deprecated term for content combining HDR + WCG.
EDR | Extended Dynamic Range | Apple Ecosystem | A system-level framework for rendering HDR content and highlights on Apple devices.
EDR | Entertainment Dynamic Range | Perceptual Science | The practicable dynamic range for consumer media, between steady-state and full human adaptation.
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