Sky UK’s Technical Specification for Delivery of Content represents a rigorous, policy-driven approach to HDR that directly addresses the epidemic of “HDR in name only.”

The specification is unique in tying technical delivery requirements to creative intent and perceptual impact—a bond other streamers’ specs omit.

A strict policy on paper doesn’t guarantee perfect compliance in practice. Without access to their programming here in Vietnam, it’s impossible to verify how consistently Sky enforces these rules. Nevertheless, the mere existence of such detailed clauses gives content partners clear, enforceable criteria and signals that Sky is serious about HDR quality.

In an industry where many platforms accept “100-nit HDR,” Sky’s specification demonstrates that it is possible-and necessary-to demand more. By requiring a perceptual improvement, mandating an HDR-first workflow, and threatening rejection for non-compliant grades, Sky’s policy protects the creative potential of HDR and ensures that viewers actually receive the enhanced experience they’re promised.

If other streaming services adopted similar contractual language, it would force a systematic upgrade in how HDR is produced and delivered, ultimately benefiting creators and consumers alike.

How Sky’s Specs Reject the 100-Nit Narrative

“There are filmmakers who I work with whose answer is identical: ‘I want the HDR to be identical to the SDR. I want it to have the same dynamic range. I want it to have the same color gamut. I want nothing whatsoever to change. All I want to change is the deliverable itself because that’s being required of me by the studio.’” – Cullen Kelly, Colorist, Entrepreneur

Section 3.2.5.3 High Dynamic Range

*“It is perfectly acceptable to deliver scenes or projects at 100 nits or less in an HDR delivery.” *Kevin Shaw, CSI, LinkedIn comment (Nov. 2025)

Clause on Perceptual Improvement: “HDR grades must offer a perceptual increase in dynamic range over SDR. Transient overshoots… which are detectable on equipment but barely perceivable to viewers, do not qualify.”

“I bet you’ve probably heard this one too: ‘I want my HDR to look like my SDR.’ This is a very reasonable statement.” – Samuel Bilodeau, Product Manager, Imaging Content Solutions, Dolby Laboratories, Dolby Technical Webinar (Spring 2024)

“I was in a feature films in which everything was done on SDR until the grading. The camera test was SDR, the LUT created was SDR, the dailies were SDR, the offline was SDR. Then the DP came and said I want the movie to look like the offline IN SDR. So it was impossible to convince him other way. And the LUT created from the colorist for SDR obviously it wasn’t working for HDR. So the solution was to create the SDR dailies exactly but within the HDR container.” – – Cristóbal Bolaños López, Colorist, LinkedIn Comment (June 2025)

Clause on Rejection: “HDR grades which offer little, to no benefit over SDR, will be rejected.” This is the enforcement mechanism.

Section 4.1.2.1 Format Categorisation

*“The only line that can be drawn objectively is SDR’s 100 nits. Anything above that in principle is HDR.” *Yoeri Geutskens, “We Need to Talk About HDR”. FlatpanelsHD (Oct. 2020)

Clause on Observable Benefit: “It is fundamental that there is an observable benefit between the different standardised formats… Content will be rejected where there is not a perceivable improvement.” This applies at format level.

Appendix 4: HDR Grading Guidance

“I like to… start with a standard dynamic range rendering of an image within an HDR container and then to slowly lift the veil…” – Cullen Kelly, Colorist, “Clients love how I use the Creative Potential of HDR” (Colorist Society, Mar. 3, 2025).

Clause on Workflow Priority: “Consideration must be given to providing the optimum HDR image. To avoid an overly reserved approach… the initial grade should be completed on the HDR version, with the SDR grade being completed afterwards.” This bans SDR-first grading.

*“Fundamentally for me, I don’t want HDR versus SDR to determine where my highlights sit. I want ME to determine where my highlights sit. So at a default, when I’m flipping from SDR to HDR, THAT shouldn’t change my rendering… So that’s why at the baseline, your HDR peak luminance, your image is going to look very, very similar to your SDR. In fact, it’ll look identical if you’re calibrated to 120 nits like my displays are.” *Cullen Kelly, Grade School , YouTube (Sept. 2025)

“If I flip you in between my SDR and my HDR rendering of your image and I show you what I think the HDR should be, you’re not going to see much change, really. What you’re going to see is some little twinkles and sparkles come to life.” – Cullen Kelly, Colorist & Entrepreneur, Grade School, YouTube (Sept. 2023)

Clause on Rejection for Inappropriate Use: “Inappropriate use of the dynamic range, without editorial justification, will result in content being rejected.”

This prevents arbitrary or gratuitous brightness that doesn’t serve the story. (e.g., in SDR-first workflows, excessively bright windows that serve no narrative purpose or emphasizing highlights only to meet a technical checkbox).

For every excuse, every corner cut, and every compromised workflow—Sky’s got a clause for that.