The highest resolution supported by the NEC PA621 is 4096 x 2160. That's over three times the resolution of a 1920 x 1200 (WUXGA) data projector, which is the most common resolution supported by projectors of a similar spec and age to the PA621. 1920 x 1200 (WUXGA) is also supported by this projector. In addition, this data projector support supported graphics resolutionss of 2048 x 1080 and 2560 x 1600 (WQXGA) and 640 x 480 (VGA).
This projector's resolution (4096 x 2160) is in fact the best supported resolution amongst all projectors of a comparable type and age to the PA621.
The worst supported resolution amongst comparable types of projector is 640 x 480 (VGA).