Now that we’ve looked at lumen output and contrast it is obvious that the lumen output listed by the manufacturers is much higher than what we measured. Did we do something wrong? Hardly, as we used the standard ansi-lumen measurement and used a calibrated professional lux meter. It won’t surprise you that there’s a number of reasons why most manufacturers list a much higher lumen output than you’ll be able to use with the projector, simply because bigger numbers sell. One obvious way to generate more lumens is to measure lumen output with the projector’ brightness and contrast setting at maximum. That this generates an overly bright and washed out image is not listed in the specifications. We’ve used the default factory settings for all projectors so we get a fair comparison between them.



Fig 2. The full specifications of the three projectors, including price, features and our measurements.
As for the noise levels there’s not much we can conclude from our measurements as all manufacturers use their own means of determining the projector’ noise level. We used an insulated and padded box in which the projector was placed with a 0dBA ambient soundlevel. For the noise level, or rather sound pressure level, measurements we’ve used a professional sound pressure level meter costing several thousands of dollars and calibrated according to IEC-60651, Class-1. The actual measurements are in dB with an A-weighted curve to fit the sensitivity of the human ear, the maximum error is +/- 0.7dB. As our measurements show most projectors have noise levels around 35…38dBA. But to be honest, from a subjective point of view, we experienced some projectors as having a less annoying noise level than others. This is due to the character of the noise, for example the pitch and whine produced by the fans cooling the projector lamp.