#129 JVC REPRINT:Layout 1 2/7/08 1:54 PM Page 4
ThEROGERSREPORT
JVC®
PERFORMANCE
GRAY SCALE
4Widescreen Review • Issue 129 • March 2008
image proportionally in the vertical and horizontal directions to fill the width of the screen.
Unfortunately, there is no native
The new
Lamp Mode
The projector utilizes a
The Normal lamp mode (170 watts) produces approximately 85 percent of the brightness of the High mode (200 watts). In the High mode the fan noise measured 51 dB,
Gray Scale
An AccuPel
The factory default Color Temperature (High, Middle, Low) meas- ured 7208 Kelvin, 6506K, and 6147K, respectively, at 70 IRE. The Memory1 and Memory2
The Memory1 and Memory2 Color Temperature modes include a set of Red, Green, and Blue adjustments that affect the entire gray scale range, instead of the usual sets of RGB gain and RGB bias controls. Hence, those controls don’t provide the ability to independ- ently adjust the low end of the gray scale, but the gray scale tracking was more constant than most projectors that have those controls. In addition, you can use the RS2’s new Custom Gamma adjustments to individually vary the RGB amplitudes over the entire gray scale range to further optimize the gray scale tracking.
The Red, Green, and Blue Offset adjustments also affect color temperature. Those adjustments again affect the entire gray scale range, but they affect all of the Color Temperature modes (hence the Offset terminology). It may appear confusing to have multiple sets of controls, but the purpose of the Memory1 and Memory2 color tem- perature modes is to allow the user to have additional color tempera- tures for specific applications. The purpose of the Offset adjustments is to recalibrate all five of the Color Temperature modes simultane- ously, which is useful during initial setup and when the spectral out- put of the lamp shifts as it ages. Again, you can apply the Custom Gamma adjustments to further optimize the gray scale tracking.
I readjusted the Middle Color Temperature using the Offset con- trols, but without using the Custom Gamma adjustments, to produce exactly D65 at 70 IRE. That produced a gray scale deviation of only 3 dE from 10 to 100 IRE. That calibration is shown in the accompany- ing charts and was used for brightness and contrast measurements. (I use 2 dE as the standard reference white deviation for making brightness and contrast measurements to ensure that all projectors are measured with comparable calibration.) With the Custom Gamma
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