What Determines CCTV Quality?

[JackOfAllTrades 0]

I installed 11 CNB domed cameras. The quality is decent but unless the person is in front of the camera, their faces are not that crisp and clear.

 

What determines the quality of the picture? Is it just the CCTV itself, or the DVR, or the power source?

 

Also, who makes a really good outdoor camera that allows for manual zoom controls from the DVR?

[Soundy 1]

I installed 11 CNB domed cameras. The quality is decent but unless the person is in front of the camera, their faces are not that crisp and clear.

How wide are the lenses? The wider the shot, the more area it covers, the less detail you'll get - that's just physics.

 

What determines the quality of the picture? Is it just the CCTV itself, or the DVR, or the power source?

The answer to that depends partly on how you define "quality".

 

It starts at the camera, of course... with analog cameras, you're bottlenecked by the video standard itself (486 vertical lines for NTSC - you can't get higher vertical resolution with analog). Then there's the sampling resolution of the DVR - CIF, 4CIF, D1, etc.).

 

And there's the compression used - all DVRs use some form of "lossy" compression, where a picture is analyzed and data that's deemed "extraneous" is discarded. The higher the compression level, the lower the image quality, but the less space and bandwidth used.

 

Also, who makes a really good outdoor camera that allows for manual zoom controls from the DVR?

There are lots. You're talking about a PTZ (pan-tilt-zoom). They're not cheap though, and they're not particularly beneficial in most cases without a human operator, because despite being able to move and zoom in on something, they can still only see that one thing at a time. If you zoom it in on a section of sidewalk to get a clear facial shot, you'll miss someone sneaking by on the lawn around it... if you widen the shot to get the lawn, you lose the detail of someone coming up the sidewalk.

[ak357 0]

It starts at the camera, of course... with analog cameras, you're bottlenecked by the video standard itself (486 vertical lines for NTSC - you can't get higher vertical resolution with analog). Then there's the sampling resolution of the DVR - CIF, 4CIF, D1, etc.).

 

486 ?

NTSC is 525 vertical lines

[Soundy 1]

Yes, but not all are visual information.

 

http://en.wikipedia.org/wiki/NTSC#Lines_and_refresh_rate

NTSC color encoding is used with the system M television signal, which consists of 29.97 interlaced frames of video per second. Each frame is composed of two fields, each consisting of 262.5 scan lines, for a total of 525 scan lines. 483 scan lines make up the visible raster. The remainder (the vertical blanking interval) are used for synchronization and vertical retrace.

Okay, I was off by three... in any case, you won't find an NTSC DVR that samples at over 480 vertical pixels, so the point is the same: your biggest limitation in "image quality" is the video standard.

[ak357 0]

Yes, but not all are visual information.

 

Okay, I was off by three... in any case, you won't find an NTSC DVR that samples at over 480 vertical pixels, so the point is the same: your biggest limitation in "image quality" is the video standard.

 

I was not looking for any

and you know my opinion about any Analog DVR on market

Soundy usually we more interested about Hor not Vert resolution

and my opinion biggest limitation is DVR ability to reproduce what been recorded

[shockwave199 0]

Before a simple problem gets twisted into rocket science, how about some pics from some of your cameras that you're not happy with. That'll tell the tale one way or the other.

[ak357 0]

Before a simple problem gets twisted into rocket science, how about some pics from some of your cameras that you're not happy with. That'll tell the tale one way or the other.

 

You know very well how many times this "?" was discussed before

do u really wanna go there again ?

I respect what u done, I respect what You like

I simply have my own opinion

about so called "D1" recording

that all

If You want I will gladly call you direct to talk about in private

Thx

[shockwave199 0]

LOL! Take it easy there man! I simply mean that sometimes a simple thing can get over analyzed, that's all. I'm gonna guess from the OP's description the problem is probably this-

 

How wide are the lenses? The wider the shot, the more area it covers, the less detail you'll get

 

And that's why I suggest a look at some pics from his cameras would help determine the problem. But the OP titled this thread 'what determines CCTV quality' and that's open to larger discussion too- so rock on. Let's just say I'm looking at the smaller picture and you're looking at the larger one, that's all.

 

[Soundy 1]

Before a simple problem gets twisted into rocket science, how about some pics from some of your cameras that you're not happy with. That'll tell the tale one way or the other.

 

You know very well how many times this "?" was discussed before

do u really wanna go there again ?

I respect what u done, I respect what You like

I simply have my own opinion

about so called "D1" recording

that all

If You want I will gladly call you direct to talk about in private

Thx

None of this is relevant to the OP's question.

[MaxIcon 0]

Simple answer:

 

In general, 3 things affect CCTV video quality, usually measured in TVL:

 

- The lens quality

- The camera imaging capability (combo of sensor, electronics, software, and settings, but it's all in one package)

- The image compression (for IP video or recorded analog video)

 

Like most things, you're limited by your weakest link in that chain.

 

The viewing angle from the lens makes a difference in how far away you can resolve something, but lens quality is what matters when comparing, say, a $30 6mm and a $300 6mm lens. Neither one will let you identify a face at 100' on an analog camera.

 

As was pointed out, your resolution in analog is inherently limited by the analog standards.

 

Going to MP IP cams can give a dramatic improvement in video quality, often at a considerable increase in per camera price, but once you go MP, it's hard to go back to analog, in my experience.