JVC DLA-RS2U, D-ILA, 1080p user manual Performance Gray Scale, Lamp Mode

#129 JVC REPRINT:Layout 1 2/7/08 1:54 PM Page 4

ThEROGERSREPORT

JVC® DLA-RS2U 1080p D-ILA® Front Projector

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 (dot-by-dot, pixel-by-pixel) mode to display video input signal formats with less than 1920 x 1080 pix- els, which there is for PC signals. The Resize function for PC signals provides three modes. It can fill the vertical height of the screen with the PC aspect ratio, or fill the 16:9 screen aspect ratio, or display the PC signal mapped 1:1 within the native 1920 x 1080 pixel screen.

The new V-Stretch mode allows an external anamorphic lens to be used. It stretches 2.35:1 images to fill the screen, which are then restored to the correct aspect ratio without letterbox bars by the anamorphic lens.

Lamp Mode

The projector utilizes a 200-watt UHP (Ultra High-Pressure) pro- jection lamp. The nominal useable lamp life is 2,000 hours. The lamp is user replaceable and priced at $399.

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, C-weighted at 12 inches from the exhaust port of the projector. In the Normal mode the noise level dropped below the 50 dB sensitivity of my sound meter.

Gray Scale

An AccuPel HDG-4000 Calibration generator (www.accupel.com) was used to generate test patterns for measuring light output, con- trast ratio, gray scale, and color accuracy.

The factory default Color Temperature (High, Middle, Low) meas- ured 7208 Kelvin, 6506K, and 6147K, respectively, at 70 IRE. The Memory1 and Memory2 color-temperature modes are initially preset the same as the High mode. The Middle Color Temperature deviation from D65 (x = 0.3127, y = 0.329, dE = 0) was only 2 dE at 70 IRE, and the gray scale tracking was within 4 dE from 10 to 100 IRE. That is excellent out-of-the-box performance.

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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