Signal to noise ratio?

[Roca]

Hi guys

Was reading a bit on the new EX 1R, and it supposedly has a good signal to noise ratio... this is a concept i never understood 100%... i mean i know it has to do of how much of the signa is actually usable, but i was trying to read more on it, and so far i only find too technical explanations that dont really help!

Any thoughts, mighty wizards?

 

[GuyB]

At 0db it represents the level of noise in the image (relative to the level of image).

EX1R 54dB
PMW350 59dB
MSW-970P 63dB

As the value is a dB measurement (which is a logorithmic scale), you have to note that 1dB represents a double in value. Therefore the difference between 54dB and 59dB is 5dB, but thats not a small difference, 5dB is 2x2x2x2x2=32 times the difference (the difference between 54dB and 43dB is a factor of 512.

 

[Sumfun]

As the value is a dB measurement (which is a logorithmic scale), you have to note that 1dB represents a double in value. Therefore the difference between 54dB and 59dB is 5dB, but thats not a small difference, 5dB is 2x2x2x2x2=32 times the difference (the difference between 54dB and 43dB is a factor of 512.

Actually, 6 dB represents a double in value when measuring voltage, which is the case here. Here's a short explanation of how SNR is measured in video signals. There is a chart at the bottom, showing the relationship between SNR in dB and noise in milliVolts. Notice that when the noise doubles, the dB number goes up by 6.

http://www.cctv-information.co.uk/i/Signal_to_Noise_Ratio

 

[GuyB]

fair enough, I'm a little more pure maths background...

still makes the 350 around half the noise as the EX1 which is nice. I wonder what the S/N in the EX1 is like at -3dB