TV Test Charts
Horizontal resolution is one of the most important characteristics in CCTV. It defines the ability of CCTV to distinguish fine details and distant objects. It's measured in the so-called TV-lines (TVL) - the number of black and white superfine strokes, which can be distinguished. On the other hand, the more the number of TVL, the smaller the details and the farther the removed objects to be observed. As to total videosystem resolution, it depends on all elements: cameras, lenses, amplifiers, cables, video signal processing devices, monitors, quads, multiplexers and so on.
It's very convenient to use the test charts for experimental definition of the resolution of whole videosystem and its parts as well (see, for instance, chart by CCTVLabs: http://www.cctvlabs.com/index2.html.
We developed 6 charts for measurement horizontal resolution, they provide testing within the range: (100:190) TVL, (200:290) TVL, (300:390) TVL, (400:490) TVL, (500:590) TVL and (600:690) TVL.
What's the difference between them and the existing charts? Usually, the resolution measurement is carried out on the so-called "wedge" of converging lines. It's necessary to note that the higher resolution, the more difficult to determine the large number of TVL (but it's the main argument in video equipment choosing). Besides, the chart with the strokes allows to evaluate the band width.
For using the charts they should be load down into your computer and print out on high quality paper by the laser printer.
For correct use of the charts it's necessary to place each of them perpendicularly to lens axes and the distance should be such that reference points (black triangles on top and bottom of the chart) would be on the lower and the upper edges of monitor's screen. Only in that case the measured number of TVL will be correct.
The evaluation of the horizontal resolution carries out on the monitor screen - the number in the last clear strokes block is a real TVL. It's necessary to use high quality lens to evaluate horizontal resolution of the camera only.
It's possible to use these charts for evaluation the quality of the focusing and distortion of the monitor and lens as well.
Download test charts: