I enclosed my 600w Bell and Howell 301a in some cardboard to block leaking light. Big mistake. It got real hot and actually warped the fresnel lense. So, I need to replace it. I've looked it up, and apparently its 14" focal length. They have them at www.bulb-source.com but want $50 for the lense. That's more than I want to spend. Any recommendations for a cheaper lense, or perhaps even a better setup? I just got a Proxima 944 and would like to stick with OHP. Maybe I need to just get a new 600w OHP. Any suggestions?