Typical Brightness Is Not Peak Brightness
A panel that peaks at 1,000 nits may sustain less than a third of that across a full white screen — and both figures are real, just answering different questions.
Two Numbers, Two Conditions
Peak brightness is measured on a small white window — commonly 10 % of screen area — surrounded by black, for a burst duration of seconds rather than minutes. Thermal mass absorbs the spike; power-delivery circuitry can overdraw its sustained budget briefly; the result looks impressive on a spec sheet.
Typical brightness — sometimes labelled "full-screen sustained" or "APL 100 %" — is what the panel delivers across a fully white image held long enough for thermal throttling to settle. On an OLED, this can sit below 200 nits where the panel sustains 1,000 nits on that 10 % window, because driving every emitter simultaneously accelerates organic degradation and heat build-up; the panel's power-management firmware cuts brightness to protect both lifetime and junction temperature. On LCD, the gap is smaller but still real: the backlight driver current-limits under sustained load, and local dimming cannot help when the whole frame is white.
The physics behind peak nits and the APL dependency means the two figures are not contradictory — they are describing the same hardware under different duty cycles. A 10 % window at 1,000 nits is asking the panel to generate the same total lumens as a 100 % window at 100 nits. The power budget is the constraint; geometry is just how you work around it.
For any honest evaluation, you need both numbers. Peak determines how bright a specular highlight or a small HDR reference point can get; typical determines whether a spreadsheet, a browser, or any predominantly bright scene will stay legible without the panel visibly dimming over thirty seconds. A spec sheet that lists only one of them is, charitably, incomplete.