Cattle Pen Gunnison, County, Colorado – 1999
11/07/2025
On this blog I’ll be posting photographs that I made with the 4×5 Leonardo pinhole camera, as well as a bit on the camera and exposure process. Eventually I’ll touch on some alternative printing processes. I have made many negatives with this pinhole camera over the years.
I was fortunate to have a darkroom off and on until 2005 when I made a move, I have not had space to work since then, so I made some changes. Then in the same year, I began working with the pinhole using color transparency film which gave me a positive color image on film. This was commercially processed. That continued in a limited fashion, and I got great results, but it was expensive. The color transparency films have gotten both scarce and expensive today, making it a distant choice.
Pinhole camera basics
The pinhole camera owes a lot to Leonardo Da Vinci. He wrote the oldest known clear description of the camera obscura in 1502. He described how light passing through a small hole could project an inverted image onto a surface. The camera obscura has been used by artists since 1650, during the Renaissance, to understand linear perspective better.
My ready made “Leonardo” made by Eric Renner (1941/2020), who was a leading expert in pinhole photography. This pinhole camera is a small wooden light tight box. It has a very tiny (.020” or 5mm) hole in the front which projects the image onto film that is secured on the back.
The 4×5” pinhole camera with a filmholder inserted, ready to shoot
Because we are working with a tiny aperture (opening) very little light is able to enter the camera. This is called a fixed aperture, there is no way to adjust the size to let in more light in. I specifically want this tiny aperture. So, the only control we have over exposure is time. Normal shutter speeds for modern cameras are from 1 second to 1/4000 sec; lens apertures are large compared to the pinhole. The exposures for the pinhole range from 1 second to several hours depending on lighting conditions. A thing called reciprocity failure happens with these long exposures. The solution to this is increasing the exposure even longer using a mathematical formula of (metered exposure time = x) x^1.26 (1.26 being the reciprocity factor of Ilford Delta 100 film).