The UK has about 1.85 million CCTV cameras and the average Briton is caught on camera 70 times a day, police figures have suggested.
The new estimates suggest there are less than half the number of cameras in the UK than previously thought.
Deputy Chief Constable Graeme Gerrard, the lead on CCTV for the Association of Chief Police Officers (Acpo), said the latest numbers, based on a map of CCTV systems in Cheshire, were intended to "inject more rigorous figures into the debate" over Britain as a surveillance state.
The widely-used estimate of 4.2 million cameras in the UK was based on a 1.5km road in a busy shopping district and extrapolated out for the entire UK.
And the previous estimate that the "average Briton is caught on security cameras some 300 times a day" was based on a fictional tour of CCTV hot-spots.
Writing in CCTV Image, Mr Gerrard said: "Eight years after the 4.2 million figure was first published, we now have research that indicates that the figure is less than half this guesstimate. We also know that unless you make a particular point of visiting as many CCTV hotspot areas as you can, you are unlikely to be captured on CCTV 300 times a day."
He admitted the latest figures were still estimates, but said they showed the number of CCTV cameras in the UK to be around 1.85 million. "And the real figure for the number of times the average person is likely to be 'caught' on CCTV in a day is less than 70 - and most of these will be at your workplace or fleeting glimpses by cameras located in shops".
Earlier this week, the Home Office unveiled plans for a code of conduct to better regulate the spread of CCTV amid fears there will be "unchecked proliferation" without it.
It also said features such as facial recognition and powerful zooms were "coming closer to being an established part of the CCTV landscape" and that cameras were now being used in taxis as "a natural part of industry growth".
While acknowledging unmanned spy drones were not currently widespread, it added that their use should be considered "within any overarching strategy".