Hello! First of all I want to say that I am not a physicist, but an artist currently doing my master thesis. I have been trying to build a solar powered slide projector. It works very simple – I reflect sunlight through a slide and enlarge it with a lens. My problem was that I wanted more juice. Stronger light. I figured that I could concentrate sunlight somehow. I have tried to make a facett reflector that focus on a pair of condenser lenses… this has not been very successful I'm afraid. Could it be that my condenser lenses has an EFL that is not the same as my fresnel enlarging lens? Do you guys have any ideas on how to accomplish this? I'm super grateful for any help what so ever! :D Cheers!