Over the years, as I've moved from place to place (apartments), I've always made it a point to set up a room (usually my bedroom), as a camera obscure. There's just something I enjoy about waking up to see the world projected on my wall, watching cars zip by, and people mulling around.

I initially began with a hodgepodge of cardboard and poster board gaffed up over a window with a small hole punched in the middle, simple, crude, somewhat effective, though pretty fuzzy.

My most recent set-up evolved into sections of mat board carefully butted together and taped over the window, with a large hole (about the diameter of a toilet paper tube) in the center surrounded by a paper slot designed to hold an index card. I then had a pile of index cards with varying apertures that I would switch out depending on the level of incoming light or desired DoF, along with an unaltered one with which to block everything. This design proved to be effective as well as versatile, although still somewhat fuzzy.

Well it's that time again. I've gone without my camera obscura long enough, and I'm ready to build and improve once again. I've a 50mm enlarger lens laying around that I don't much care for the print quality of. The idea of mounting it on a spare lens board and using it for a (hopefully) sharper projection has been rolling around in my head for a little while now. I'm curious as to whether or not anyone around here has tried using an enlarger lens for this sort of thing, and if the result was worth the effort. I'm considering either projecting onto a wall that is approx 12.5ft away, or combining an angled mirror to allow me to orient the lens upward and project onto the ceiling. The latter would at least allow some latitude to vary the distance between the lens and projection surface, although it would complicate the build design.

Any advice or insights would be greatly appreciated.