How to determine if you 600TVL camera is REALLY 600 TVL

[QC444 1]

Hello,

 

Is there any way to determine the ACTUAL resolution of a camera?

 

I bought two cameras both 600tvl

 

One appears to be decidedly sharper than the other.

 

Is it "possible" I was sent a 420 TVL instead?

 

How would you actually test the resolution?

[tomcctv 187]

Hello,

 

Is there any way to determine the ACTUAL resolution of a camera?

 

I bought two cameras both 600tvl

 

One appears to be decidedly sharper than the other.

 

Is it "possible" I was sent a 420 TVL instead?

 

How would you actually test the resolution?

 

 

Hi. There is no way of knowing..........also position of cameras will give you diff eat quality. ....with light and environment. And remember 600tv lines is black and white ......not colour mode. So they will be around 560tvl

[Kawboy12R 0]

Wonder if the focus is a bit off on one? The fuzzy cam might be just a smidgen off. If there's no external focus you might be able to open it up and turn the lens to help. Might void your warranty though.

[shockwave199 0]

Are both cameras being hooked up to the same cable for comaprison? If a crude eye test shows one to be better than the other, I'd buy a second of the one that appears to be decidedly sharper than the other, and return the other one. A simplistic approach I know, but why dick around.

[MooreHe86 0]

Hello,

 

Is there any way to determine the ACTUAL resolution of a camera?

 

I bought two cameras both 600tvl

 

One appears to be decidedly sharper than the other.

 

Is it "possible" I was sent a 420 TVL instead?

 

How would you actually test the resolution?

 

Hello,My dear friends, there is one easy way to determine these two camera.

Different DSP system has different resolution, the dsp system of 420tvl is CXD3142+ICX633/2.

and the 600tvl is NVP2040+ICX639/8, most of manufacturer use these two dsp system for their camera. and how to separate CXD3142 from NVP2040? see the attached picture, you can find the model of the DSP on the back of the board camera.Thank you.

[MaxIcon 0]

OK, there's always confusion on this topic.

 

Actual TVL is a combination of 3 or 4 things:

 

- The sensor

- The lens

- The camera electronics and processing/compression

- For IP cams, the decompression and viewing software

 

In addition, the display device can reduce the apparent resolution of the camera - a fuzzy monitor will not show a high TVL device output well - and the recorded resolution will usually be different from the live view resolution. Live view is what you care about, since that's the camera's output.

 

The weakest link defines the best TVL you can get. A junk lens will give a $1000 camera a poor TVL result.

 

Now, to measure actual TVL, you need to be able to focus on an ISO12233 chart that fills the screen vertically, then find where your resolution becomes unreadable. This is easier said than done, but this is the only real test.

 

So, measuring the actual TVL is tricky, but measuring relative TVL is easy. Go to this site:

http://www.graphics.cornell.edu/~westin/misc/res-chart.html

 

and download this PDF:

http://www.graphics.cornell.edu/~westin/misc/ISO_12233-reschart.pdf

 

Print it on the largest sheet of paper you can, on the best printer you can find (laser printers are better than inkjets, in general), and mount it where you can view it with both cams.

 

View it through both cams with the paper taking up the same amount of the screen for both (easy if they have the same lens size, takes moving it if they don't). Focus the lens for the best resolution of the lines, then figure out where the lines become blurred, and that's your relative TVL for that cam.

 

You can then test things like switching lenses between the cams to see how much effect the lens has.

 

Here's a good overview of TVL measurement:

http://www.acti.com/getfile/KnowledgeBase_UploadFile/TVL-The_True_Measurement_of_Video_Quality_20101027_002.pdf