How can I achieve zoom lens functionality? For optimum projection quality, the LL lenses are fixed and don't incorporate any zoom functionality. Zooming is quite a technical operation requiring multiple (and usually expensive) lenses to do it properly. It would be nice to be able to have a setup that is flexible (say, if you ever need to move the PJ to a new location), but having a fixed zoom is one of the prices we have to pay for exceptional picture quality at an affordable price.

Various ideas have been forwarded over time, from using some sort of fresnel, to "glasses" for the projector. While these seem like good ideas on the surface, in the end, the final projected image quality depends on the weakest link in the optical chain. The more you attempt to change the focus of the projector, the greater the effect of the lens that you use to do it. If this is a fresnel, you might as well be using a fresnel as your projection lens. It will be terrible. Even a quality single lens will show a lot of distortion.

If you want a zoom lens, you can get one, but they tend to only work well for small panels. Also, ask any photographer. They'll tell you that a single-focus lens will ALWAYS get you better quality than a zoom lens will.