Please refer to the Christie Lens Calculator on this website or the downloadable PDF throw distance chart located in the downloads tab of this lens option or the downloads tab of Christie projector to be used with this lens. Applies to: Christie LW401 Christie LW551i Christie LW651i-D Christie LW751i-D Christie LWU421 Christie LWU501i Christie LWU601i-D Christie LWU701i-D Christie LX501 Christie LX601i Christie LX801i-D