S/N Ratio

[Thomas 0]

I'm trying to make sure I understand this concept. When looking at the s/n ratio (as expressed in Db) the higher the number is, the better the camera is?

[Cooperman 0]

Correct,

 

The only problem with comparing specs, is that we don't know exactly what the conditions were, when the cameras were tested.

 

So comparing like for like can be a bit hit and miss. Some manufacturers, particularly the reputable ones, are more accurate (or should that be less creative) than others.

 

S/N as a guide, fine; written in stone, I'd rather pass.

[Thomas 0]

I've noticed that manufacture's specs are pretty vauge. A number I've seen will list horizontal lines and others will list vertical lines.

[Mrcctvtech 0]

S/N is a measurement of a ratio between the electrical video signal and the "background" noise.

The bigger the better.

You can also try to do not add more noise to your system, by choosing a good coaxial cable, good connectors and good installation practices, such a not sharp bends and not running cables close to power electrical cables that supply voltage to machines, tools or motors.

S/N is an exponential number, that means that an increase of, let say 3dB may mean DOUBLE resistance to "backgroud" electronic noise. A camera with 50dB should be far better than a camera with 47dB

 

Regards

[AliB 0]

Thomas

Don't get confused between horizontal lines and vertical lines. All cameras and monitors use 625 horizontal lines - UK PAL system. NTSC of course different but the principle isthe same

The resolution of a camera/monitor defines how often the signal can change in one line. A 480 lines camera will diaplay a change of 480 items across that line.

If you looked at the vertical bars of a jail door and there were 480 bars across and the camera image just captured the door you would need a 480 line camera to display all the bars.