The NEC PA622 supports a maximum resolution of 4096 x 2160. That's over three times the resolution of a 1920 x 1200 (WUXGA) projector, which is the most common resolution supported by 6000:1 contrast ratio data projectors that came out around the same time as the PA622. 1920 x 1200 (WUXGA) is also supported by this projector. In addition, this multimedia projector support supported graphics resolutionss of 2048 x 1080 and 2560 x 1600 (WQXGA) and 640 x 480 (VGA).
A 4096 x 2160 supported graphics resolutions is in fact the best supported resolution across all projectors of a comparable age and spec to the PA622.
Across comparable types of multimedia projector the worst supported resolution is 640 x 480 (VGA).