Varifocal or fixed lense?

[perky416]

Hi guys.
Been looking at new cctv cameras and narrowed it down to two. One has a varifocal lense but no built in mic and is £250 a pop (i need 7), the other has a fixed 2.8mm lense with a built in mic (£150 each).
For the perimeter of your property do you really need varifocal lenses? Arent they more for focusing at objects at a distance?
I liked the idea of fine tuning the image coverage with the varifocal but dont really want to sacrifice the mic and dont want to use an external mic.

 

[secureiam]

recording public audio could get you into bother so be wary about audio coverage.

as for how many you need cant comment as don't know the application or the property being covered.

As for lens it comes down to what you need it to cover.

2.8mm is a wide lens so covers a large area and pixel density will be lower than the same camera with a 4mm lens which will be covering a smaller area.

to put it another way:-

You have to work out what its covering and if the lenses available for the camera with the resolution of that camera are capable of what you want to achieve.

Its not a case of needing a fixed lens or a varifocal lens.

what cameras were you looking at and why?

 

[perky416]

I didnt consider the law on it, i just sssumed as you can record in a public place audio is acceptable. Ill have to research it.
The audio as good, one time my neighbour a few doors down had his car stolen, the thief walked to the bottom of my drive on his phone so we could hear he was talking in a different language. Another time my ex turned up and started threatening me, the audio captured it all. More recently over the road had their car broken into. You could hear the window break and then the thieves walked off and waited to see if anyone heard it. Ill look into the audio properly.

I have attached a pic of my current cctv (quality lacking and struggling to load as im on my mobile). I basically want to replicate this with a better system that has the alarm output as mentioned in a previous post. The main purpose is to monitor intrusion onto my property, i also want to protect certain areas such as the wall of my garden and area around my car with the line protection feature so it can trigger my house alarm if anybody crosses at night for example.
The 2 cameras cover the street as my ex used to park around the corner or down the road and walk to my property. Should anyone come and try to steal from me by doing this i i wanted to capture their vehicle.

My original choice was the hikvision DS-2CD2H85G1-IZS, it has everything i need apart from the audio option. I then saw the DS-2CD2386G2-I(U), it has everything but isnt varifocal.

 

[secureiam]

what you got now?

 

[perky416]

Swann 885msb cameras with the 8580 nvr.

 

[secureiam]

so you have 8MP cameras already, just the live views on your phone wont show the 8MP in all its glory to be fair, so the images will look worse on there than they actually are, assuming your cameras are on full res

 

[secureiam]

given these are wide angle cameras, and your seeing a lot of next doors property, then I would look at your house on ivpm calculator and use 4/5MP cameras with 4mm lens to see what I get roughly before jumping up to 8MP, you could look at the color vu or full colour options from Hik or Dahua.

you can put your exiting cameras on to see how they compare too?

 

[perky416]

Yeah 4k atm as i say im on the phone so the quality is lacking. I really only wanted to change to get the alarm function, but on the other thread where you said dont use swann cameras it got me thinking...i hate them. The app is terrible, the advanced functions like line cross etc are useless as the notifications are either always on or always off as i cant hook them up to an alarm, id be triggering them every time i go home. Some of the app functions dont work and the cameras constantly fail to load.

 

[secureiam]

to be fair line crossing outside is difficult to get right as its so changeable.

lots of reasons why they could fail to load.

 

[perky416]

That calculator was very hand good shout! I think im going to go for the varifocal, just seems so much easier to get the coverage i want.

With the varifocal do you have the option of narrowing the horizontal field of view whilst leaving the vertical at maximum? Or is it simply a zoom so both FOV reduce at the same time?

 

[secureiam]

NO.

Its easier than working out which lens you need, occasionally when I work it out I need a 6mm lens to get optimum and it isn't always so easy to get a 6mm fixed lens without ordering it in specially or paying more from a different distributor. Varifocal is cheating in some respects, but it can help and it also means you can change how close you are to the object of interest.

on some cameras you can flip the H and V, or you can look at the resolutions available and that will give you the pixel options X by Y

Its based on the sensors capabilities and how much of the sensor is used, for example I have had some HIK cameras were the view was increased with a firmware update because not all the senor was being used, but that isn't so common.

 

[sparkymarka]

Just buy varifocal ... then you can set it at whatever you require ....it not worth the hassle for what they cost !

 

[secureiam]

7 cameras at £100 difference each is £700?

 

[sparkymarka]

depends on brand ...

 

[secureiam]

I was referring to the options under consideration.

depends on technology used price wise motorised TVI is cheaper than IP, but 8MP recording rates are pretty poor