RedRocks
Here's more subject matter on aluminum sheet. This is a lens prototype I made out of old LF Artar barrel connected to an Ilex #5 shutter and a positive meniscus lens element which connects to the rear of the barrel.
I created this prototype to mimic the soft focus effect of the old Pinkham & Smith lenses.
Good luck w/playing around w/your gear on these types of surfaces.
Take care