Today is Worldwide Pinhole Photography Day.
Pinhole Photography is the making of images using no lens (no glass, plastic, et cetera).
The light from the subject is projected through a tiny pinhole onto a surface within the camera.

For this session I used a device I made with a hole in a thin piece of aluminum, sandwiched within a T-Mount adapter for P/K Pentax bayonet mount.
I installed the adapter on a Pentax *ist D digital SLR to record my images.
The hole is approximately 0.3 mm in diameter, and set 48 mm from the focal plane within the camera.
This yields an effective aperture calculated at about f/160.

I used a hand held meter to get an approximation of of exposure value, noted the reading at f/8, then used a conversion chart to find an appropriate shutter duration at f/160.
These settings are outside the range of auto exposure capability for the camera body, so I dialed in the times with Manual Mode selected.
With the digital camera body, I was able to select high effective ASA settings of 800, 1600, and 3200. At these settings, my exposure times varied between 1/2 second and 30 seconds, depending on the strength of the light on my subjects.
Such settings in the digital capture gave interesting effects with grain and color in the final images.
These long exposures were a real drain on the batteries, no surprise.

Please click on thumbnails to see enlarged.
All images are Copyright 2013 E.J.Kowalski.