How To Tell How Many Lines Of A Camera?

[spider]

Rotakin testing will be able to define the displayed resolution in tvl, also playback, a new digital testcard version is soon to be released

http://www.rotatest.com/page7.html

[Doktor Jon]

As redbull has already suggested, at the most simple level, you would ideally need to use a proper test chart to establish exactly what resolution the camera is capable of producing.

However .... at one end of the scale, if you can establish from the packaging what camera you have, you could possibly get a confirmation from the manufacturer (or UK supplier), precisely what the unit should have been doing when it originally left the factory.

That said, quoting a resolution figure for a camera is only a relatively small part of the story in a strictly legal sense.

For example, let's say that you have a camera fitted with a quality CCD imager that is capable of resolving 520 lines.

Now if the manufacturer sourced a particular batch of lenses from a new factory, and optically they were inferior to the ones used when the camera was originally tested (assuming that it has at some stage in the past been properly tested ), then it's unlikely to resolve the same detail with poor quality optics fitted.

If the camera is then installed with poor quality cable, dodgy connectors, a power supply that is 'under running' the camera, light reflecting off the optics or dome cover, dust on the lens, or any one of half a dozen other common factors, then what may in theory have started off as a 520 line unit, may well end up with 20 or 30% (or more) reduction in measured performance, if it was set up and properly assessed on a test bench.

Given that testing a camera properly does require some degree of 'expert' knowledge, in an ideal world, if you were able to do so I would have suggested getting an independent opinion of the cameras performance.

[kai]

I have actually just finished writing an email to them asking them to provide proof that it's a printing error and for the proper specifications of the cameras that I have been supplied. The next step is to contact the supplier of cameras and ask them directly for the specifications. Finally, if push comes to shove I'll try hiring out an independent CCTV professional who knows his stuff... I'm willing to stand my ground and will name and shame depending on treatment or I will congratulate and recommend if everything gets resolved amicably.

Anyone able to recommend someone who would be able to tell me precisely what I got based in the south?

Edit: Oh yes, in answer to the question as to what made me choose them. It was a combination of things, firstly they boast a very large list of clients on their website. They sent someone round for a no obligation quote who seemed to know what he was talking about, they followed up with a quote in email like I asked them to (I did have several others in and you'd be surprised at how many didn't bother to follow up after an initial site consultation) and their prices were competitive. (Now I may just be about to find out why! )

[billythebellbox]

However .... at one end of the scale, if you can establish from the packaging what camera you have,

betting a

[james.wilson]

and their prices were competitive. (Now I may just be about to find out why! )

that was mainly what i was getting at. But you do need to try and resolve this directly with them first. It may be that you have fantastic 520tvl cameras and all is very well indeed

[Alarm Protection]

Are they an approved company and if so take the right steps!

[topalarms]

betting a

[Adi]

betting a

[kai]

I think it is and if its the varifocal lense camera, it is a 540tvl, if its a fixed lense it could be a 540tvl.

Question is does it give a clear sharp image that your happy with?

I think that the cameras are from LJD too as that's where the DVR is from (there's a big LJD sticker on it).

Are you saying that in either case it's 540TV lines? Which surpasses the 520TV lines that I was quoted for? I don't think that the cameras are varifocal.

I would say that the images aren't actually that clear to be honest. I have seen better. The issue isn't the cabling as I did had that done independently with very high quality RG59 coax.

Edit: and now I have just been denied in my quest to find out what cameras I have. LJD point balnk refuse to help me out over this matter since I am not in the CCTV trade. I don't know if anyone here in the trade can be so kind to help me get the correct specs of this camera?

Another thing that has come to my attention is this: Basically the job was supposed to be completed before today (12th May), however they didn't read the email I sent them that stated this and they booked in the job for 13th May and so I actually just accepted this. However, they gave me a call later on that day (Thursday 8th May) to say that they were in the wrong and so would rush someone out to get the job done. However, they didn't have enough cameras in stock and so would be delivering the cameras directly to my premises and the installer would do the install. I have been looking on the LJD website and I have noticed that on their armour dome camera section, the camera 'Armour Dome 520 TVL IR LED VariFocal Dual Ring' (Model: LJDEYE-101VFHBL) which seems to match what's on my spec sheet I was given, is listed as out of stock and was listed as out of stock on the the 8th May too. This does make me feel a little bit uneasy as I have my suspicions that they couldn't get that camera in on time (thier fault already) and decided to go with this other model and hoping that I wouldn't notice.

I have yet to hear back from the company that have done the install.

[kai]

Ok, I've just had some news back from my installers and the gist of it is this:

They basically supply two different cameras, both have 1/3" CCD, one is 420TVL and the other is 520TVL. They reckon that 95% of their customers have 420TVL as they are cheaper and people cannot detect the difference in image quality. They now admit that they have installed the wrong cameras for me, but have charged me a price (I haven't paid yet) for 520TVL cameras.

They are offering to do one of two things, adjust the quote price or reinstall all correct cameras. The price differential isn't that much that they are offering to adjust in my opinion.

I am considering getting them to switch all cameras as I can't say that I'm hugely impressed with the image quality that I have at the moment.

Anyone else think that this is the right way to go?

Once this mess is all sorted out, I'll let people know who these people are.