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lense types; please help


Guest thewatcher

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Guest thewatcher

I could do with some help choosing appropriate lenses for body cameras; I understand the basic difference in the field of views that can be obtained by using different lense sizes, i.e. 2.5 mm will give say a 120 degree and 12mm will give say 40 degrees etc.

However, I need help identifying the pros and cons between the different lense types available for body cameras, i.e. what is better and what can I achieve with:

Manual Iris v Auto Iris v Vari focus v Auto focus v zoom options etc.

My requirements are as wide a field of view as possible, with the lense being able to deal with a range of daylight and nightime light fluctuations, for instance 1 camera will be placed south facing and get sunlight from behind, at side and in front, i will also use cameras at night time too (Sony "Ex-view HAD" CCD type)

If I wanted maximum flexibility with as much automation and less fiddling as possible what would you advise?

Thanx for your help in advance, the reason I need advice is that we have had our fingers seriously burnt by the incorrect specification of equipment and a seriously bad installation of CCTV already by a multinational security co. (lets just say butt fire and security) that has caused immense stress, cost & have decided to have the lot removed and start again, I am fairly technically minded and want to know what I am talking about BEFORE tendering this contract to protect us from the same mistake.

regards

a friendly neighborhood newbie to cctv

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Get yourself a specification for tender written up by a professional.

Pay for someone to survey your site, and do an Operational Requirement for the system, Then propose a system design that fits in with your operational requirement.

The information you are asking for will be of little use if you dont know why you want it in the first place.

What area are you located in?

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Guest thewatcher
Get yourself a specification for tender written up by a professional.

Pay for someone to survey your site, and do an Operational Requirement for the system, Then propose a system design that fits in with your operational requirement.

The information you are asking for will be of little use if you dont know why you want it in the first place.

What area are you located in?

46921[/snapback]

Thanks rich, based in south east England, I have had three co's survey this place so far and they have all been unacceptable to us due to a lack of being able to give me what I know I can have, for example they all wanted to supply analogue to video VCR systems, none of them have been able to supply digital, so I have spent the last week researching & looking at the options for digital to PC and have decided to opt for this setup. See my other post for more info; Geovision system supply and install required, experienced install co wanted

Not to be rude buddy, but the type of suppliers I have had dealings with so far have really cost me a loss of confidence in the industry as a whole (they were all large national / international Co's) and I currently have a legal case in process with what appeared to be the biggest of them all (*~# Fire & security) after what was originally a 3 day intruder alarm & cctv install turned into 19 days on site before being told to disappear fast, due to serious damage to my listed properties interior and exterior, faulty systems, false alarms and cctv that doesn

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(Rich @ Apr 5 2005, 02.43pm)Get yourself a specification for tender written up by a professional.

Pay for someone to survey your site, and do an Operational Requirement for the system, Then propose a system design that fits in with your operational requirement.

The information you are asking for will be of little use if you dont know why you want it in the first place.

Hi thewatcher,

Sorry to hear you've had such a bad experience with a security install.

Being technically minded is very useful when trying to understand the 'technicalities' of CCTV, but with the best will in the world, and no disrespect intended, you are unlikely to pick up enough relevant advice and information quickly enough, to guarantee that you won't come a cropper again, even on a relatively simple point.

As an example, if you spec'd a 12mm lens thinking it was going to give you the coverage you require, depending on which format camera the installer supplies ( e.g. 1/3" or 1/4" ), you will get a completely different effect from that which perhaps you were hoping for.

I have to agree with Rich 100% and more; in that it isn't just a simple case of understanding

the application, or indeed its technical requirements, but you also need to be aware of all possible options, permutations, and even more importantly, cutting through the c**p so that an eventual contractor is identified for the quality of their proposed system, and not simply that you end up being blinded by science.

Having an expert on board should only cost you a relatively small sum, but could easily make all the difference to your project. After all, would you prefer to design in detail your own major building improvements, or would you consider it more appropriate to employ the services of an architect...?

I'm sure others will have even more advice for you,

Good luck with the court case,

regards,

D.J.

http://www.doktorjon.co.uk

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Guest Peter James

Agreed with all the above, each lense has its own benifits dependant to the application.

Wide angles are ok if you want to see lots of small things, and visa versa for say a 12mm lense.

Auto Iris / Direct Drive will depend on the the camera (and can even come down to what direction the cameras pointing)

We are in Worthing West Sussex, established a while, (with no big law suits on our back) we would be happy to help if your close enough.

Pete

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Without looking at the property it would be not possible to specify a Camera and lens combination that will cover what you want to view.

Why dont you ask the NSI Expert that is working for you in the court case to write the specification, or if they cant, get them to reccomend a consultant who can.

By the sounds of things you need someone who has the skills to install a system within a listed building, without damaging it further.

It may be that you have to consider a higher specification of equipment in order to achieve the neccessary result.

Defensor Security in Chichester, have worked in a lot of properties like yours as they are fairly common in West Sussex. Their Website or telephone 0870 741 3640

Get your new installer to provide you with refferences and take them up.

Colin.

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