I have seen larger fresnels over at that other diy site.... how do these compare to LumenLab lenses?

Are they usable to get the full 15" picture? not much info about them.

Would like to build something big enough for a 17"-19" panel and use a 15 or smaller for now . But upgrade to a larger panel just by swapping out the panel

The big problem with those fresnels is the short focal length he ordered. With the current fresnels we are already at a 1:1 throw ratio. If you were to use a 17" monitor with those fresnels you're projector would only be 5-6' away from the screen; not the direction most of us are trying to go. We are getting large fresnels and a custom zoom lens to correct this problem.

That's great news brain, any idea of when you might start selling these items?

Archi, I'm waiting on the new projection lens sample to verify it's construction. Last word was that it should be ready soon. Best guess is withing a couple of weeks I can start taking orders but this will be a group buy. I believe it will go quickly.