Optoma's EX525ST is their first short-throw projector, and they took the time to get it right. This projector is geared for the K-12 classroom market, with several features that make it ideal for the classroom - among them a password lock that engages automatically if the projector sits idle for too long, a control panel lockout, and an 8-watt speaker that provides plenty of sound. With street prices below $1100, the EX525ST is a great choice for smaller classrooms.
Short throw. The EX525ST needs only four feet of throw distance to put a 100" 4:3 image on screen. Many XGA projectors which are otherwise comparable need 10 feet or more of throw distance to put the same size image on the screen. In many classrooms, this would put the projector squarely in the middle of the students, which is undesirable for several reasons. The short-throw design of the EX525ST allows the projector to be kept near the front of the room, where the teacher can keep an eye on it, without sacrificing screen size.
Lumen output. In Bright mode, the EX525ST will put 2388 lumens on the screen, out of a rated 2500 lumens. This image mode pushes highlights, so it is a good choice for black-and-white text documents or similar content. For material that requires more accurate color, try using sRGB mode, which still cranked out a respectable 1763 lumens in high lamp mode. Low lamp mode drops lumen output in every mode by roughly 30%, but extends the life of the lamp by an additional 1000 hours.
Low maintenance. The EX525ST's filter-free design is made possible thanks to its sealed light engine, which cuts projector maintenance to vacuuming the vents on occasion, and switching out lamps when they expire. And with an estimated 4,000 hour maximum life, lamps do not expire often. Replacement 200-watt P-VIP lamps cost $349 from Optoma at the time of this review, for an estimated cost per hour of eight cents.
Powerful sound. The EX525ST has an 8-watt speaker, which is more than what's available on most other projectors in its weight class. Using our standardized test tone, we measured a volume of 75 dB at a distance of three feet - plenty loud enough for a classroom setting. In fact, you'll want to be careful not to seat anyone too close to the projector, as 75 dB could be described as "uncomfortably loud."
Security features. As the EX525ST is ideal for use on a rolling cart, it is important to make sure that it doesn't roll away on its own. To this end, the projector has several security features which, taken together, combine to make the EX525ST one tough cookie.
First up is the password function, which will lock the projector's controls if it is left idle for a given amount of time - the timer can be modified or disabled from the menu system. Next is the control panel lockout, which makes the projector useless without the remote since the top-mounted control panel will simply cease to function. Third is the wired networking function, which not only allows the projector to be controlled from a central location, but also allows a network administrator to be notified if the projector is unplugged. Finally, the EX525ST has locking points for both a cable lock and a Kensington lock, making it less likely that the projector will be stolen to begin with.
Express replacement warranty. In the event that your projector breaks, getting it fixed as quickly as possible is very important. Optoma's "Express" Replacement warranty means that they will ship you a replacement projector before you even send them the malfunctioning unit, limiting downtime to the absolute minimum possible. This does vary somewhat over the course of the warranty; during the first year Optoma sends a refurbished projector, but during years two and three a "loaner" is sent while your projector is repaired. However, the end result is the same: you have a working projector in the classroom again in a matter of days, not weeks.