The Ricoh PJ X6180N supports a maximum resolution of 1920 x 1200 (WUXGA). That's over seven times the resolution of a 640 x 480 (VGA) projector, which is the most common resolution supported by projectors of a similar type and age to the PJ X6180N. 640 x 480 (VGA) is also supported by this data projector. This projector also supports a supported graphics resolutions of 1024 x 768 (XGA).
A 1920 x 1200 (WUXGA) supported graphics resolutions is in fact the best supported resolution amongst all data projectors of this age and type.
Amongst similar types of projector the worst supported resolution is 640 x 480 (VGA).