Projector Reviews

Most manufacturers seem to have settled on a claimed lamp life of about 2000 hours for their digital front- and rear-projection displays, though a few have claimed considerably more. Replacement costs hover around $300—again, with notable exceptions. Because 2000 hours comes to about 1000 movies (though fewer than 200 viewings of The Lord of the Rings trilogy!), most high-end video fans will find the expense tolerable.

But, short of total failure, how does a lamp's light output hold up over time? Normally, UAV writers put fewer than 100 hours on a projector under review—too little time to accumulate any useful data on this subject.

For unrelated reasons, however, we managed to put considerably more time on both the BenQ PE8700 and the Sharp XV-Z12000. We also had light-output measurements for both projectors, both out of the box and after approximately 250 hours of use. The effective light output of each dropped by about 30% during that period. (The Sharp was measured with its Economy mode off and the iris at its Mid setting.)

These results should not be read as flaws in these specific projectors, both of which are superb products. Rather, it is an alert that the issue of useful, rather than ultimate, lamp life is seldom dealt with, and it could well affect many manufacturers, if not most of them. We also don't know if, after that initial drop of 30%, a lamp will stabilize at a lower level for an extended period of time, or continue to steadily degrade. Many projector owners report that they're still getting good performance from their projectors as they approach the limit of a lamp's rated life. But it's possible that the eye adjusts over time, without realizing it, to subtly degraded performance. When I installed a nearly new lamp in my 250-hour PE8700, the image improved dramatically.

To be fair, the results here are limited to a very small sample. But they do suggest two tentative recommendations. First, manufacturers should investigate this issue openly. And second, video perfectionists might have to replace their lamps a lot more often than they'd planned if they want to continue to get the performance they paid for.—TJN