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Doktor Jons

Guide to Closed Circuit TV (CCTV)

So would you like to play "Spot the CCTV Camera?". Eagle eyed visitors may recognise the profusion of street furniture, surrounding a single heritage dome camera keeping watch over part  of Londons' prestigious Oxford Street shopping area.

All you need to know about lenses,
for all types of video surveillance.

Technical & Engineering Information about CCTV Lenses (continued)

Selecting the correct CCTV lens for any given application takes a little bit of practice, but as Doktor Jon has mentioned before, there are a few useful pointers which can help to make the task easier.

Firstly, in terms of general performance / flexibility in use, the 1/3” CCD format will provide pretty much almost everything that you need for 90% of applications; and given the enormous range of lenses available, if you can’t find one that fit’s, it's really time to consider a career change!

Wherever possible, if you are selecting a fixed lens, try and use the series designed for the next larger sized imager; so if you have a 1/3” camera, if at all possible stick to 1/2” or even 2/3” format lenses.

Try and remember the lens ratio guide for that format: Ultra Wide = 2:1 Wideangle = 1 :1 Standard = 1 : 2

Yeah, so what does that mean? Okay, well if your camera is pointing at a wall 10 metres away, with the Ultra Wide lens the picture will take in very roughly 20 metres width of wall, with the Wideangle 10 metres, and with the Standard 5 metres ..... and not a lens calculator in sight!

To give you a better idea about the range of lenses available, Doktor Jon has thoughtfully provided a simple comparison chart.

Oh and don’t forget, when comparing lenses always make sure that the manufacturers data is indicating the horizontal angle of view, and not the diagonal angle of view.

Too many lenses have been bought and installed, when they are simply not right for the job!!


So have a quick look at Doktor Jons brief lens guide>

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resulting from any individual or organisation acting on the details contained herein.

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