Short-throw projector lens allows for large-screen projection from a short distance.
https://diqn32j8nouaz.cloudfront.net...s_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...653#post189983
https://www.homemadetools.net/forum/...965#post187271
https://www.homemadetools.net/forum/...291#post192249
