We are still waiting for a statement from Casio regarding the brightness issues we've seen on the new LED/Laser Hybrid light engines. But in the meantime, we have some more test results to share...
Since we have had a total of five units in house, we've been able to do some extended usage testing to see if the Hybrid light engine maintains its brightness and color characteristics over time. Our findings thus far are that maximum lumen output drops over the first 100 hours of use. On one of our XJ-A130s, the max lumen output was 1228 when it was new. After 130 hours of use its maximum brightness dropped to 949 lumens, which is a 23% reduction.
The Casio User's manual indicates that the high altitude mode of operation (which increases fan speed and audible noise) is recommended at elevations above 3300 feet. We do our testing at 3100 feet. Since this is close to the limit, we decided run a second test with the high altitude fan engaged. The second unit started with a maximum reading of 1630 lumens, and after 100 hours of run time its maximum lumen output had dropped to 1470, or a 10% drop.
Two notes of caution are in order. First, in order to get 100+ hours of use on these test units, they were run with a 100 IRE white test pattern continuously, 24 hours per day. This is not the way people normally use products of this type. We do not know whether brightness degradation is exaggerated by continuous use. More testing of a wider array of samples under different usage conditions would be required to support any definitive conclusions.
Second, we do not know the degree to which our 3100 foot elevation is affecting results. It may be that brightness degradation would proceed at a slower pace at sea level. Though the test unit with the high altitude fan engaged has diminished less over the first 100 hours of use, this was a much brighter unit to begin with. Furthermore, it draws 178 watts in full power operation, whereas the dimmer test sample draws only 138 watts. There are too many variables, and not enough test data, to draw any certain conclusions.
We have noticed another interesting phenomenon as a result of the extended usage test. Color balance on the first of the two units (the one which now measures 949 lumens) actually improved after 130 hours of use. Initially the picture had excessive blue and green components with very little red. Now it looks more neutral, with red coming more into balance with green and blue. It appears that the red component, which comes from the LED, remains relatively stable in its light output, while the blue and green that are produced by the laser diminish over time, causing the unit to trend toward a more neutral color balance.
So far we have seen this on just the dimmer of the two test samples. The brighter of the two units still shows a significant weakness in red, and color balance on this sample is quite poor.
We will continue to run these units to see what further developments ensue. And we will report any information forwarded to us by Casio once they have had a chance to evaluate the issues at hand.