Posts Tagged ‘security cameras’

CCTV Surveillance Facts?

Thursday, March 5th, 2009

CCTV Surveillance Camera

CCTV camera statistics are often quoted to illustrate how we are all watched by 300 cameras a day, and how many millions of security cameras there are in the UK.

We’ve commented on these ‘facts’ previously and pointed out that they never seem to increase since we first quoted them over five years ago, and wonderment at how these numbers of installed surveillance cameras were ever established?

There was an interesting piece in The Guardian yesterday by Paul Lewis, with many links to research and the original documents that first cited (in some cases made-up) these claims.

David Aaronovitch has been snooping on statistics. His mission: to get to the bottom of the dubious claim, often quoted as fact, that the average Briton is caught on 300 CCTV cameras a day.

The statistic is fiction. Or at least was written as such when it first appeared in 1999 in the book The Maximum Surveillance Society. The author, Sheffield University’s Professor Clive Norris stated clearly in the book that the “contrived account” of a day in the life of a man called Thomas Reams was “a fictional construction” designed to mirror the reality of routine surveillance. That important detail appears to have been lost when the estimate was referenced in a landmark study for the Office of the Information Commissioner.

The original detective work of chasing these stats was carried out by David Aaronovitch in an article in The Times:

The mystery stat was sitting on one of our Times blogs and read “the average Brit is caught on security cameras some 300 times a day” and, God knows why, I just decided to chase the number down and find out where it came from. The colleague responsible for the blog referred me to a couple of news stories, and to a document issued by the office of an important and newsworthy quango.

Lux Light Level Chart

Monday, December 1st, 2008

Lux light levels chartLux levels are quoted by all IP camera manufacturers to indicate the low light level capabilities of their cameras.

The problem is that the lux scale means nothing to most of us, and we are often asked to give an indication of just what is meant by 1.0 lux or 0.01 lux.

Somehow, us saying “quite dark” or “very dark” never seemed very satisfactory!

We checked with Wikipedia:

The lux (symbol: lx) is the SI unit of illuminance and luminous emittance. It is used in photometry as a measure of the apparent intensity of light hitting or passing through a surface. It is analogous to the radiometric unit watts per square meter, but with the power at each wavelength weighted according to the luminosity function, a standardized model of human brightness perception. In English, “lux” is used in both singular and plural.

That’s that cleared up then! 😉

We don’t really think that the information on the Wikipedia page is quite what our CCTV camera enquirers are looking for, so we’ve created our own lookup lux chart with indicative pictograms to give you a visual representation of relative lux light levels.

Click the link to view the chart as a pdf – Lux Light Level Chart.

We hope that’s helpful?

You might also be interested in our article on IRE and Lux Levels.

If there’s any other CCTV terminology that we can de-mystify for you then please feel free to get in touch and let us know. You can use the comments below or visit our IP CCTV Forum.