TAG DVD32FIR manual Test patterns

30 test patterns

test patterns

The DVD32FLR has a in-built test pattern generator to assist you in adjusting your picture, PAL or NTSC, for best performance.

Many display devices are wrongly adjusted when leaving the factory because they need to overcome the bright lighting in the show rooms from which they are usually selected. However, once installed at home, the viewing conditions vary considerably from those in the show rooms, hence display devices need re-calibrating.

Most important for a perfect picture is the absence of surrounding light in the room, particularly light which can hit the screen. An often suggested low brightness light, placed behind the screen (hence preventing it from reflecting in the screen) should only be used if you want to watch tv leisurely for a long period of time. For best movie presentation, keep the surrounding light intensity as low as possible.

It is not just the absence of surrounding light which can improve the performance of your display device, it is also the colour of the walls, as these will also reflect light, emitted (or reflected, when using a front projector) from your screen, ‘bouncing’ it back on to the screen to ‘wash-out’ the picture. The perfect home cinema would be pitch black with no added light in the room! Not the most pleasant of rooms, but highly effective. The result would be great picture quality, assuming the display device is up to the task and adjusted properly. A more practical solution is walls painted in darker colours without a reflective surface.

test patterns 31

brightness (black level)

Black is the absence of light, and this is the first parameter you should adjust. Use the display device’s black level control which some manufacturers call, quite inappropriately, brightness.

The DVD32FLR includes two test patterns, PLUGE 1 and PLUGE 2, which will allow you to adjust the black level until black becomes ‘really’ black (and not just a dark grey). If you set the black level too high then a scene filmed at night looks like a scene filmed in the afternoon (as black will be replaced by dark grey). However, if the black level is set too low then the picture will lose detail in dark scenes.

Both test-patterns include a signal, created by hardware circuitry inside your DVD32FLR(1), which produces a level which is electrically below black, i.e. invisible if the black level of the display device is correctly adjusted. This signal is called PLUGE (Picture Line Up Generating Equipment). Both test patterns also include, to the right of PLUGE, separated by a black zone, a dark grey bar (electrically above black, by exactly the same amount as PLUGE is below).

If the black level is correctly adjusted then PLUGE is no longer visible but the dark grey bar still (just) is.

PLUGE 2 contains, in addition to PLUGE 1, a brilliant white field to check if the black level is affected by high picture contrast.

1.The DVD32FLR will not display the blacker than black test signals recorded on some test discs as it will remove those ‘out of spec’ signal levels. Some video processors will not display PLUGE at all