To overcome the disadvantage of the low light output of common LCD Projectors when used in combination with polarizing filters, we developed a new combination of half-wave retarder plates and a polarizing filter. The paper points out, that the use of modern LCD Projectors in combination with the newly developed filter results in less light loss than using standard polarizing filters for stereoscopic projections either with LCD or DLP Projectors. We have combined a color selective half-wave retarder plate (CSR) with an achromatic half-wave retarder plate (AR). The CSR with its optical axis oriented 45° to the green light only rotates the spectrum in the 520nm-565nm range by 90°. This means that the red and blue components remain untouched and all the light passing through the first filter will be oriented vertically. The AR then is oriented in that way that all the light after the CSR will be rotated to the desired +/-45° polarization state. We added a third high transmissive polarizing filter with its orientation parallel to the transmitted light in order to cut off any noise which is not perfectly polarized.