How to Make a Long Throw LCD Projector

Sometimes it is necessary to extend the throw length of an LCD projector while keeping a small image size.  This can be done if an approbate lens is obtained.  unfortunately the available lenses may not cover this case.

My approach is to look carefully at the LCD projector specifications and find one with a  element size equal or less  than the size of a  35 mm film slide.   In this case the  lens from a 35 mm camera can be used.   35 mm lenses come in huge variety of focal lengths.  I used an Epson projector.

Furthermore the process of mounting the lens can be enhanced if rather than mounting a lens you mount the lens mounting ring from a 35 mm camera.    This allows you to mount any of  the available lenses  In my case I choose Pentax cameras and obtained a ring from a broken Pentax camera body.  Broken cameras sold for parts are available cheap from Ebay.

All that  is left is to remove the existing lens,  replace it with a plate on which the mounting ring is secured and attach the lens of your choice.