Image caption The BBC is promoting the trial as providing the "best ever picture quality" iPlayer has offered
The BBC is to stream dozens of World Cup matches live in 4K resolution and high dynamic range colour (HDR) to UK-based audiences in June and July.
However, it will limit the number of screens with access, and will do so on a first-come first-served basis.
The BBC also plans a separate virtual reality experience. One expert said the news had been highly anticipated.
"There had been a couple of earlier trials that had not been highly publicised, but now everyone who has compatible equipment should be able to see some of the best picture quality made available via a terrestrial broadcast," commented Andy Madden, content editor at What Hi-Fi? magazine.
"They should see a marked improvement in detail and a brighter, punchier picture than they had previously."
The term 4K - which is sometimes referred to as being ultra-high definition (UHD) - refers to the fact that an image contains four times as many pixels as a 1080p high definition picture.
This can reveal details that would otherwise be obscure - including the notes written on a yellow or red card, or the time on a referee's watch.
The technology takes advantage of the fact modern TVs can go brighter and/or darker than they used to, providing a greater dynamic range.
As result, the shadows of an image can be made less murky while the highlights - including glints of light reflected off metal or water - can be given more impact.
HDR is also accompanied by the adoption of a "wider colour space", meaning millions more colours can be displayed than had been the case before.
BT began screening live sport in 4K in 2015, and Sky followed a year later, but neither do so in HDR.
The BBC is able to, thanks to the development of a new type of HDR called hybrid-log gamma (HLG), which has been created in conjunction with the Japanese broadcaster NHK.
But each will be limited to "tens of thousands of people" - the exact number of iPlayer-equipped devices has not been specified in advance.
To gain access, viewers must be among the first to click on the relevant home screen button just after each stream starts.
To enjoy the optimum experience, the BBC says audiences will need a 40 megabit per second (Mbit/s) internet connection - which is faster than that to which most households have access.
BBC engineers first trialled the tech involved in public in April, when they streamed a rugby league match between York City Knights and Catalans Dragons.
More recently, they streamed the second half of the FA Cup final between Chelsea and Manchester United.
However, neither event was publicised in advance, so attracted a much smaller audience than the forthcoming competition in Russia should deliver.
In addition, the BBC plans to offer live virtual reality views of 33 games via a dedicated app, that will take account of the viewers' head movements.
It will be made available closer to the time on iOS and Android devices, as well as the Gear VR, Oculus Go and PlayStation VR headsets.
It will allow users to switch location to get the view from a "luxury private box" on high or from behind either of the two goals.
While many experts see 4K and HDR as a natural evolution of today's normal broadcasts, there are doubts as to whether VR will become mainstream in the same way.
Sales of dedicated headsets have been weaker than originally forecast and compelling content has been limited - often because of the added cost involved in creating it.
If done well, live sports coverage could help drive demand, but the risk is that it feels like a gimmick.
"Virtual reality is still in its infancy and has still to catch on with the masses," commented Mr Madden.
Watch highlights from England women's 1-0 win against Brazil at Meadow Lane thanks to an early goal from Fran Kirby.
So claims Mauricio Macri, the centre-right politician who became president of Latin America's third largest economy in December.
The US-educated businessman has made it a priority to mend relations with foreign powers and investors after 10 years of combative rhetoric under his leftist predecessors, Nestor Kirchner and his wife (and later, widow) Cristina Fernandez de Kirchner.
Soon after his swearing-in ceremony, Italian Prime Minister Matteo Renzi and French President Francois Hollande travelled to Buenos Aires to expand co-operation.
But President Barack Obama's visit this week to Argentina, just over 100 days into Mr Macri's term, is the most significant.
The trip underlines Mr Macri's determination to re-insert Argentina into the global economy, and his desire to build a mutually beneficial relationship with the US.
Mr Obama also wants to fulfil his longstanding promise to open a new chapter of engagement between Washington and Latin America, one that acknowledges progress made by the region's democracies.
In Buenos Aires, Mr Obama and Mr Macri are expected to increase co-operation in areas such as trade and investment, renewable energy and climate change, and citizen security.
During Nestor Kirchner and Cristina Fernandez de Kirchner's decade in power, Argentina became politically and financially isolated.
The Peronist couple had a belligerent relationship with Washington, whom they accused of "imperialism".
And following Argentina's massive debt default in 2001, they turned their backs on the International Monetary Fund, which they said had been a "destructive" influence on the nation's economy.
They imposed strict capital and currency controls, claiming this would stop multinationals and financial speculators from draining the country of cash, and prevent a devaluation of the Argentine peso against the dollar.
The Kirchners also fought a fierce battle against what they called "vulture funds", foreign investors holding $9bn (£6.25bn) in bonds on which the country defaulted.
These bonds were bought by hedge funds NML and Aurelius Capital Management for a fraction of their face value in the aftermath of Argentina's economic collapse in 2001.
The lengthy dispute - which led Argentina to a second default in 2014 - has restricted the country's access to international credit markets.
However, for millions of Argentines the Kirchners' decade - which was also very strong on social policies - restored the nation's pride.
But then it started to slow down because of its excessive reliance on the domestic market, the lack of foreign investment and credit, and declining global demand and prices of agricultural products, Argentina's main export.
As a consequence, the country was forced to seek investment from far-away nations such as China and Russia.
In his first months as president, pro-business Mr Macri has tried to overturn almost every one of his predecessors' key policies.
One of his first moves was to resume contact with the US and other global powers "to restore the important role Argentina should have in Latin America and the world".
He lifted capital and currency restrictions, and started talks with big international banks to get loans.
Mr Macri's government also began negotiations with the bondholders, offering to pay 75% of their outstanding claims. Some have already accepted.
However, many Argentines think the president's "winds of change" have looked more like a destructive tornado so far, as a number of controversial measures have deeply affected their everyday lives.
In January, the government stopped subsidising utility bills, and electricity prices went up by almost 300%.
And the peso lost about 30% of its value against the dollar in one single day after he decided to lift restrictions on the currency market.
Mr Macri's administration has also started to cut public spending - which doubled under the Kirchners' administration - by cutting thousands of jobs in government offices.
The opposition has accused the president of carrying out a "political cleansing" by removing civil servants hired by the previous government, and of fuelling unemployment.
In addition, Mr Macri has bypassed Congress, introducing many of these changes by issuing decrees, which critics have described as an "authoritarian" move.
The detention of high-profile social leader Milagro Sala on corruption charges in northern Argentina also proved to be controversial. Ms Salas had very close links with the previous administration.
She established the organisation in 2001 when the Argentine economy was in desperate trouble, and many of the poor were struggling for food. Its powerbase is the northern Jujuy province
Tupac Amaru channelled government funding to food and housing for the poor, and built schools, clinics and factories
However, opponents accused Sala of monopolising control over state resources, and abusing her position for political gain
She was was detained in January as she protested about reforms to social spending being implemented by Jujuy's provincial government
She is accused of siphoning off funds for social housing that were distributed through her organisation
Mr Macri's ascent to power after a comfortable win in last year's election might have been good news for international markets and creditors, as well as the US and other global powers.
But political and social discontent could become an obstacle to his aim of boosting Argentina's standing in the world.