Cinematography-Theory-And-Practice

Figure 9.17. Blue-only color barsshown in black-and-white for clarity.Notice that the bands are of equalintensity, and in the upper portionthe large and small bars are equallygray or black. This indicates correctphase and saturation.The PLUGENotice the three narrow bars labeled 3.5, 7.5, and 11.5 on the bottomright (Figure 9.17). These are the PLUGE, which stands for PictureLineup Generating Equipment. The PLUGE was developed at the BBCin London. It was generated at a central location in their facility andsent by wire to each studio. This way all of the equipment could becalibrated conveniently and consistently. This was the PLUGE alone,not combined with the color bars.The middle black bar is set at 7.5 IRE, (or in the digital realm, 16,16, 16). The first bar on the left, superblack, is set at about 2.5 IREbelow black, and the third bar, dark gray, is set at 3.5 IRE aboveblack. None of these really work to adjust a monitor to properlydisplay 0 IRE black, so the following procedure is standard. Learningto calibrate a monitor is an essential skill. PLUGE bar is not quite visible. The lightest bar on the right(11.5 units) should be barely visible. If it’s not visible, turn thebrightness up until it becomes visible.difference between the left bar (3.5 units) and the middle bar(7.5 units). There should be no dividing line between thesetwo bars. The only division you should see is between 11.5 and7.5. This same technique is used in setting the black-and-whiteviewfinder on a video camera.level. To do so, turn the contrast all the way up. The white (100unit) bar will bloom and flare. Now turn the contrast downuntil this white bar just begins to respond.Adjusting ColorIt is possible to eyeball the yellow and magenta. This is the downand dirty method and should only be used if other methods are notpractical. The yellow should be a lemon yellow without orange orgreen. And the magenta should not be red or purple. This quickiemethod is not recommended except in emergencies; it is much betterto do it the professional way. If you do eyeball a monitor, don’t puttoo much faith in it for color reference or brightness. Monitors varywidely in color reproduction, especially in less than ideal viewingconditions on location.Figure 9.18. Incorrect luminance;notice how all three of the PLUGEbars in the lower right are visible.Figure 9.19. Correct monitor setup,shown here in black-and-white.Figure 9.20. (above, left) SMPTE75% color bars. See also Figure 9.1on the opening page of this chapter.It is typical of the kind of color barsthat will be generated by many highendHD cameras. 75% refers to colorsaturation; this is considered to bemore reliable to measure than 100%saturation, but 100% color bars doexist and you need to be sure whattype you are working with.HD cinematography163