Let’s cut through the noise: Steve Yedlin’s critique of PQ ST.2084 misrepresents its design, testing it in ways it was never meant to be used. Using the ITU’s own playbook (BT.2390), we’ll separate his claims from reality—exposing critical errors that invert the truth about HDR efficiency.
Yedlin’s Claim on PQ Efficiency
Yedlin asserts: “HDR needs 10 bits to look as good as SDR’s 8 bits” and frames PQ as inefficient.
Reality per BT.2390
Section 5.2 (Figs. 13–14) proves BT.1886 fails even at 12 bits, while PQ stays artifact-free at 10 bits. SDR hides BT.1886’s flaws—HDR exposes them. Yedlin’s critique inverts reality.
Yedlin’s Deceptive 8-Bit Demo
Yedlin states: “I’m gonna chunk it to 8 bit… That’s the HDR. Do you see how bad that is? The SDR is totally smooth at 8 bit, and the HDR isn’t,” calling 10-bit HDR a “trick.”
Reality per BT.2390
Testing PQ at 8-bit is invalid: PQ was never designed for 8-bit. Section 5.2 requires 10/12-bit pipelines to avoid artifacts. Yedlin cripples PQ while testing BT.1886 in its native SDR range (0.1–100 cd/m²)—like forcing BT.1886 to 4-bit, then declaring gamma “broken.” Figure 14 confirms PQ works at 10-bits; Figure 13 shows it’s flawless at 12 bits. BT.2390 never mentions 8-bit viability.
Yedlin’s “Wasted Code Values” Argument
Yedlin contends: “HDR’s only using 65% of up to scene white... The rest is wasted by holding out all this space for pixels that don’t exist,” calling PQ "spectacularly inefficient.”
CLAIM: PQ is wasteful for targeting a 10,000-nit range.
REALITY: Only ~7% of PQ's code space is allocated to the 5,000-10,000 nit range, providing future headroom. The curve is perceptually uniform, prioritizing more codes for lower luminances where the eye is more sensitive. Source: HPA Tech Retreat 2014 - Day 5 report, detailing the Q&A on PQ efficiency.
Yedlin's Ignorance of PQ's Purpose
Yedlin states: “I don't know why they came up with this PQ curve" while praising BT.1886 as “fantastic because it actually works.”
Reality per BT.2390
PQ solves BT.1886’s HDR limitations. Section 5.2 states traditional gamma "is not a good approximation for human vision over an extended range".
Reality per Industry Experts
“Today’s BT.1886 is not capable of HDR; in order to accommodate HDR content in the transmission chain, we'll need an HDR-capable quantizer.” Charles Poynton, Stessen and Nijland, “Deploying Wide Color Gamut and High Dynamic Range in HD and UHD,” SMPTE Motion Imaging Journal, April 2015.
Yedlin Claims Not To Know Who Developed PQ
Yedlin states: ”I don't know who came up with this PQ curve.”
Yedlin's Mislabeling of PQ as "Logarithmic"
Yedlin repeatedly calls PQ: “that PQ logarithmic curve" and “this logarithmic curve."
Reality per BT.2390
PQ is perceptually quantized (Sec. 5.2), not logarithmic. It uses the Barten vision model to match the contrast sensitivity of the human eye. Log functions waste codes at the low end. Yedlin is keenly aware that log is camera-referred yet falsely brands display-referred PQ as log to delegitimize it.
Yedlin's Data Rate Misrepresentation
Yedlin contends: “HDR is a data hog" and “at any data rate... the SDR curve is going to be better.”
Reality per BT.2390
Irony: Yedlin condemns PQ as a "data hog," but BT.2390 proves: BT.1886 needs >12-bits for HDR (Fig 13: “rises substantially above the visual threshold"). PQ delivers artifact-free HDR at 10/12-bits—the minimum for its range. Yedlin’s efficiency claim collapses.
Yedlin's Claim on Creative Intent
Yedlin implies BT.1886 preserves intent better: “SDR is the more reliable system for viewers to see relative contrast as authored by the filmmaker.”
Reality per BT.1886 & BT.2390
SDR’s OOTF alters contrast by design (Sec 2.1). PQ was engineered to preserve absolute luminance relationships.
Conclusion
Yedlin’s arguments misrepresent PQ’s design, test it invalidly, and artificially cap HDR to SDR constraints. BT.2390 refutes every claim, proving PQ is essential for preserving real-world light and creative intent beyond SDR’s limits.
Source: Debunking HDR (1:07:47)
The Daejeon Chronicles 