Gatwick, as seen from an RAF Raptor pod at a distance of 26 miles (42km)
The RAF says a new type of camera is giving pilots in Afghanistan a clearer picture of enemy forces.
The Raptor (Reconnaissance Airborne Pod for Tornado) allows pilots to zoom in on ground activity from greater distances than before.
The cameras cost £6m each and have been used in Afghanistan since Tornado jets arrived last June.
The technology is a copy of an existing system devised by the US-based Goodrich SRS company.
Although the number of cameras deployed is classified, the RAF said Raptor "has passed initial operating capability and is working well".
Test runs in Britain included one exercise in which a pilot produced a composite image of Gatwick airport, taken from 26 miles (42k) away at an altitude of 5,790m.
A similar system to Raptor was used on a flight over Southampton, during which the jet's camera was able to zoom in on the Big Ben clock tower in London.
"And yes, the clock face was visible and readable," said an RAF spokesperson.
The RAF says the system - which generates electro-optical and infrared images - provides useful data from ranges out to many tens of miles and is the most powerful ever deployed.
The cameras have already been used on a number of missions with success, and has proved especially useful in the hunt for Improvised Explosive Devices. (IEDs)
"It always makes a difference because the guys on the ground will get images of potential ambush points," said Ministry of Defence Wing Commander Julie Parry.
The camera helps pilots assess the fall pattern and accuracy of aerial bombs, and is also being used in missions termed "pattern of life".
Raptor pod mounted on the port shoulder of a Tornado GR.4A
"This is where you observe something for a period of time and see who comes and goes," Ms Parry said.
Images are viewed by pilots during flight, both day and night, and can also be transmitted in real time to ground stations for analysis.
Michael Gething, editor of Jane's Electro-Optic Systems, said Raptor's life first began in 1996 as part of an RAF reconnaissance system and was later used during the Gulf War in Kuwait in 2002.
"The point about Afghanistan," Mr Gething said, "is we need to know where people are, where things are."
"In this instance, surveillance is of prime importance. The guys they're taking pictures of don't know they're being snapped."