The television pictures of the coronation of King Charles III were incredibly impressive, whatever your view of the event. They were captured in ultra-high-definition and high dynamic range by the BBC, which provided the coverage for the international feed. The irony is that the vivid details could only be seen online on the BBC iPlayer. The BBC only broadcast pictures in high definition, while Sky and Virgin could carry them in their full ultra-high-definition glory.

A total of seven outside broadcast vehicles from four different companies were used to provide the coverage. Considerable care was taken to ensure consistency of output from each of the trucks, which used different cameras and systems. The hybrid log-gamma function, jointly developed by the BBC and NHK, was used to deliver high dynamic range, preserving details in the shadows and highlights. The increased colour gamut of the ultra-high-definition pictures also provided more faithful colour reproduction.

Of over a hundred cameras used in the production, all but two used high dynamic range. For the first time, the quick turnaround editors recorded and edited high-dynamic range pictures for playout from the outside broadcast trucks.

The pictures were downscaled and interlaced for delivery in high-definition. To monitor the spatial and temporal filtering and colour space down-mapping, a specially created version of the famous BBC testcard was used. This is based on the BT.2100 colour space and hybrid log-gamma function, so may not display correctly here.

BBC UHD testcard

While the BBC offered its enhanced coverage online through the BBC iPlayer, most viewers were watching the down-converted output. However, they still benefited from the higher acquisition and production quality.

The official viewing figures from BARB show that the average audience for the coronation on BBC One was 12.04 million, with 9.96 million watching live, a 59% share of the audience at the time, and just under 2 million watching within seven days.

A further 3.35 million watched the coverage on ITV, with just under 3 million of them watching live. That was slightly fewer than the number that watched the serial drama Coronation Street the night before.

The BBC previously reported that an average of 18.8 million people watched the coronation across 11 channels and services, including BBC One, BBC Two, ITV, and Sky News, with audiences peaking at 20.4 million as the King was crowned, just after midday.

Sky and Virgin Media O2 carried coverage in full UHD and the results were truly impressive. The pictures popped in comparison to high-definition pictures, offering far greater clarity and fidelity. This was particularly evident in the textures of fabrics.

And these pictures will be available for posterity as a record of the pomp and ceremony of the historic occasion. No doubt they will seem as anachronistic to future generations as the grainy black and white pictures of the coronation of Queen Elizabeth II seventy years ago, seen as quite remarkable at the time on a typical 9-inch screen.