The Asus P2B has fixed focal length lens with a specified throw ratio range of 1.1:1. For the following measurements and evaluations, I positioned the projector at about 88 inches from the screen, which produced an image about 80 inches wide.
Note: The testing was conducted in a totally dark room using a matte white screen with a gain of approx. 1.1, The projected image was rather dim when viewing video and photos. A smaller screen size would be more appropriate for using with this projector in a typical business setting.
Asus specifies the P2B to provide 350 lumens when operating on AC power. However, my measurements resulted in a maximum of 271 lumens. The following list presents the peak "white" lumens measurements for the P2B when operating on AC line power with factory default settings for each picture mode.
PICTURE MODE MEASURED WHITE LUMENS
White Board 256
Black Board 253
The brightness uniformity was very good with no more than a 10% drop in brightness from the peak value listed above (taken near the center of the projected image) when moving out to 3 of the 4 corners of the projected image and a maximum 20% drop near the forth corner.
With the P2B operating in "Standard" picture mode, I measured the peak light output dropping to 191 lumens when switching to battery power or (191/256 =) 0.75 which is a 25% drop in light output
The above brightness measurements were taken when displaying a full intensity 100% white test image, as the basis for these "White Brightness" measurements. With LCD and LCoS based projectors a "Color Brightness" measurement will always be the consistent with the "White Brightness" measurements. However, with DLP projectors, such as the P2B, the Color Brightness may be far lower than would be implied by the White Brightness measurements. To check for this, I used the P2B operating it Dynamic picture mode and I then projected in sequence a 100% Red, a 100% Green and a 100% Blue test images. When adding the individual lumen measurements from each of these three primary colors the Color Brightness was calculated to be about 87 lumens, or about 1/3 of the White Brightness. Art has prepared a video (click HERE) on the Projector Reviews web site that explains Color Brightness and why this metric is important.
When the P2B is being used in a small conference room with subdued lighting I would suggest for best results the image size be kept to perhaps a maximum of 50 inches (diagonal) if a white projector screen is being used. If a less ideal projection surface is being used (e.g., a off-white wall) or if brighter room lighting is present, then a smaller size projected image will probably be needed to keep the image bright enough.
The Asus P2B is specified to produce a noise level of 32 dB in normal lamp mode and 24 dB in Eco mode. These values are typical for this class of projector. While the noise level, especially with the lamp operating in normal mode, is certainly audible, it should not be distracting when this projector is being used in even a small conference room. Operating the P2B off of its internal battery places the projector in a lower power mode where the fan noise decreases to the point of not just barely be being heard from just a few feet away.