Why Contrast Ratio Matters More Than Peak Brightness (AOC 24G2SPU)
Why Contrast Ratio Matters More Than Peak Brightness explained, with the AOC 24G2SPU's own measured figures as the worked example: peak brightness is quoted because it is easy to raise. Contrast is wh...
Aisha Bello
The short version
AOC 24G2SPU, refresh 165Hz — Why Contrast Ratio Matters More Than Peak Brightness. Measured on hardware rather than argued from theory, on a device we rate for sRGB coverage is genuinely accurate.
Peak brightness is quoted because it is easy to raise. Contrast is what decides whether an image looks flat or has depth.
Why this matters: Two panels at identical brightness can look completely different, and the difference is almost always contrast.
What is going on underneath
Contrast is the ratio between the brightest white and the darkest black a panel produces in the same scene. A conventional IPS manages around 1000:1, IPS Black around 2000:1, VA 3000:1 and up, OLED effectively infinite. Peak brightness figures are usually measured on a small window rather than the full screen, so a panel advertised at 1000 nits may sustain 250 across the whole display. In a normally lit room, raising brightness beyond roughly 200 nits stops helping and contrast is what continues to matter.
What it looks like in practice
Take the AOC 24G2SPU as a worked example. Nothing else we tested under £200 included a height-adjustable stand. That is the difference this makes once you stop reading specifications and start using the thing.
| Specification | AOC 24G2SPU |
|---|---|
| Panel | 23.8in IPS, 1920x1080 |
| Refresh | 165Hz |
| Brightness | 250 nits |
| Contrast | 1000:1 |
| Ports | DP, 2x HDMI, 4x USB |
| Coverage | 99% sRGB |
| Response | 1ms MPRT |
The spread across devices
One worked example is an anecdote. Here is how the figure that drives this behaviour actually varies across the hardware we have measured in this category — same test, same conditions, so the spread is real rather than an artefact of who reviewed what.
| Model | Panel | Price | Our score |
|---|---|---|---|
| AOC 24G2SPU | 23.8in IPS, 1920x1080 | £149 | 3 / 5 |
| Dell UltraSharp U2724DE | 27in IPS Black, 2560x1440 | £549 | 5 / 5 |
| LG UltraFine 32UN880 | 31.5in IPS, 3840x2160 | £599 | 4 / 5 |
| Samsung Odyssey OLED G8 | 32in QD-OLED, 3840x2160 | £1099 | 4 / 5 |
Where the line sits
It helps to have a number in mind before you start comparing. Across the monitors we have measured, the useful thresholds are the ones where a difference stops being visible: below them you notice, above them you are paying for a specification rather than an experience. The AOC 24G2SPU reports 23.8in IPS, 1920x1080 for panel, which sits comfortably on the right side of that line, and 165Hz for refresh. Treat anything materially below those as a real compromise and anything materially above as a number you are unlikely to feel.
What people get wrong
- A brighter panel is a better panel
- HDR400 certification means meaningful HDR, when it is close to a participation badge
- Dynamic contrast figures in the millions describe anything you will see
Checking it yourself
- Reproduce the conditions rather than trusting a one-off reading — run the same task three times and take the average.
- Note the figure your device reports and the figure it actually achieves; on the AOC 24G2SPU those diverge under sustained load.
- Change one variable at a time. Brightness, background sync and ambient temperature all move this number independently.
- Compare against the manufacturer’s stated figure and treat any gap as the cost of real-world conditions, not as a fault.
- Repeat after a firmware update — this is one of the numbers that moves without an announcement.
How to use this when buying
Compare native contrast and full-screen brightness. Ignore peak-window figures and any number with "dynamic" attached.
Above about 200 nits, contrast decides how good an image looks, not brightness.
Behind this piece
Every product covered here was bought at retail and lived with for at least a fortnight before a word was written. Battery figures come from a scripted day rather than a manufacturer estimate, and sustained performance is measured warm — after half an hour of load — because that is the state a device spends most of its life in.
Where a firmware update changes a result, the piece is re-tested and the change noted rather than quietly corrected. No review unit arrives with conditions attached, and no score is agreed in advance with anybody.
Where to go next
If you are weighing this against the rest of the monitors we have covered, the category archive lists every review in date order. The closest comparisons we have published are Why Contrast Ratio Matters More Than Peak Brightness (Apple Studio Display) and Why Contrast Ratio Matters More Than Peak Brightness (Asus ProArt PA279CRV).
For the reference material behind these figures, the specification pages carry the measured numbers, and the common questions collect what people ask once something is in daily use.
