dvr recorder

[Doktor Jon]

eddiefast,

I hate to complicate matters further, but there is another issue which needs to be considered.

To get the best out of a high resolution camera, you need to use a decent quality lens.

A number of PCB based cameras are marketed as 470 / 480 lines colour, but the cheapo c**ppy lenses fitted, are quite incapable of resolving the detail which the cameras are capable of reproducing.

If you use a decent camera with interchangeable lenses, you can try (if you have them available or can borrow) a 6mm CS lens and a 6mm C lens (with 5mm spacer ring fitted).

In general, 'C' mount lenses are normally manufactured to produce much better resolution in the image, particularly obvious when the aperture (iris) is closed down two or three stops. As with all products, some manufacturers produce better quality than others, but if you stick to a decent brand you should be ok.

If you do a direct comparison (12mm CS and 12.5mm C would actually display a very noticeable difference), then you may begin to see why cheaper lenses, produce inferior results.

To be honest, if you use a rubbish lens on a 480TVL camera, and compare it to a 330 line fitted with a top notch optic, the cheaper camera will probably look better on screen.

D.J.

[Guest PaulR]

Going from 380 to 480 on most PC cards will make a difference as most cards will be able to process more info than a 380 tvl processes, and the extra pixels coming from the camera means a better image. Up to a point though.

There is a maximum display resolution and processing capability of cards & PC & screen though. 720x576 is usually considered tops, and going from a 480 camera to 570 will not make a noticable difference.

If it is put through a flat screen monitor it will not look as good as a CRT monitor, and if your graphics card is not top notch or the screen res is set too low you will not get the best. The higher the frames per second the better, up to 25 fps (real time) per camera.

Remember though, set the screen res high and you get a much smaller image on the screen.

To stop that 'pixeled' look I used to run the camera straight to a good quality CCTV monitor first (or via a switcher, quad processor if more than one) and you will get that crisp, 'BBC' quality that digital often lacks for live viewing.