The highest resolution of the Optoma DS330 is SVGA (800x600). That's 39% less resolution than a XGA (1024x768) projector, which is the most frequently found resolution.
This multimedia projector's resolution (SVGA (800x600)) is in fact the worst resolution across all projectors of this age and type.
The best resolution across similar types of multimedia projector is WXGA (1280x800).
If you want a projector with a higher resolution then you might also want to look at the MX661 (£952.77) (XGA (1024x768)), or the MX522 (XGA (1024x768)) both from Benq or the Optoma DX325 (£310.14) (XGA (1024x768)).