I'd already been doing something similar to Mark Tucker's work with the Plungercam years ago and didn't realize I was an artist.

I found a Spiratone Portragon 100/4 fixed aperture, single element lens, very primitive with heavy spherical aberration. The concept is identical to the Plungercam, except it's ready made with a focusable helical.

Great effect for the right kinds of images. You can get the same effect by mounting a close up diopter onto a macro bellows, which enables focusing to infinity.

Spiratone advertised it as an option for soft focus portraiture but I prefer it for still lifes and landscapes.

The buckets photo in my personal folder ("Study in Gray") was taken with the Portragon.