Cctv Lens Advice

[Guest advancesecurity]

Hello Martin here from advance security (west yorks), have difficulty figuring out which lens to use with our typical cameras (bosch ltc0455/11) we have been cheating by using vari-focal lenses, i would prefer to use a fixed lens as they dont creep out of focus over time, and are cheaper/shorter which means we can use a smaller housing, if anyone has a system of calculating the correct lens for a specific application, your advice would be much appreciated, also the word aperture is a word i dont understand too well! Thanks.

[ian.cant]

Try

this one

or

this one

or

this one

or

this one

or

this one

if you dont like these google for your own, there loads out there.

[Billy@Solutions4CCTV.com]

Martin

As mentioned above it is always better to go with a fixed lens option for a number of reasons including light levels etc!

Have you tried to speak to the manufacturer of your camera to see which lenses they have as a preferred supplier.... ultimately speak to them and ask them for a lens guide.

If you purchase enough through them I am sure they will be only too happy to even send you a selection of typical lenses, 3.6,8,12 and 16mm typically for you to try out.

I understand what you mean about the variable lens option, but remember not to give your customer too many options either or else you will e forever changing it !!! Unless you can sell them a PTZ on the back of it !!!!

Hope that helps

Billy

[ispy]

Hello Martin here from advance security (west yorks), have difficulty figuring out which lens to use with our typical cameras (bosch ltc0455/11) we have been cheating by using vari-focal lenses, i would prefer to use a fixed lens as they dont creep out of focus over time, and are cheaper/shorter which means we can use a smaller housing, if anyone has a system of calculating the correct lens for a specific application, your advice would be much appreciated, also the word aperture is a word i dont understand too well! Thanks.

aperture simply means hole!

in relation to lenses its how much light can pass through the iris

[arfur mo]

as a 'rule of thumb' car parks, playgrounds 3.6mm, passages/alleys 6 or perhaps 12mm on a longer passage.

as always, it just depends what your client actually wants to see, or worse what they think they will see.

to combat this problem, i use the camera on my smart phone to take a 'pot shot' which is equiviqllqnt to a 3.6mm lens, and i can then show them. i exsplain it is not an exact representation but a good idea of what they will actually see.

if they are happy i go with it. if not i can say that they will see approximately that area but with larger 'targets' pro rata depending on the lens, but always offer to swap it out within a month f.o.c. if they are not happy.

using the phone camera gets you arround the usual request to see number plates and a whole football field clearly all on one camera

i then print these images into the estimate to save any arguments later on, just because i hate arguing as all well know .

regs

alan