Just the other day I came across a reminder that creativity in spec-writing is not a lost art. Four brands of projectors sold online have been accused by Epson of misleading consumers about the brightness of their projectors. False advertising, the Epson press announcement claims Epson Files Lawsuits Against Amazon Projector Sellers for Misleading Advertising Claims | Epson US These aren’t projectors I use, but I’m glad that Epson has taken action to defend against shoddy practices within the A/V industry.
There hasn’t always been an agreed method of measuring projector brightness. Early projectors, most of them anyway, used cathode ray tubes (CRTs) hit with enough energy to throw an image across the room to a screen. While capable of modest brightness over a small area (a flickering campfire at night,) CRT projectors could not maintain this over large areas (as you would have displaying a spreadsheet.) And so the concept of “peak lumens” was born: what was the highest brightness your projector could give you if didn’t worry about area, or about keeping it in focus, or about maintaining it for an hour. We hoped a given manufacturer would use a consistent test method across their own products, but we knew there was no uniformity from one manufacturer to the next.
This couldn’t last, and in 1992, ANSI-IT7.215, Data Projection Equipment & Large Screen Data Displays – Test Methods & Performance Characteristics, was published. By the following year projectors were appearing with specifications of ANSI lumens, and we could begin to compare projectors to one another. Not only did the standard define test methods, but it did so in relation to practical applications. Specs were both reliable and useful.
There remain differences between products, in the A/V field as everywhere, and manufacturers continue to highlight their strengths and downplay their weaknesses. If the strength is low cost, the technical weaknesses can be many, and easy to hide. Reliable and comparable specifications build trust and benefit the industry.