Sharpen up...

Although blurred images can prove of interest they can also stop the communication of a point. I wanted to sharpen up my pinhole images and found an application called "pinhole designer" that enabled you to calculate the optimum diameter of a pinhole for a given focal length and much more .... visit it and see.

What I realised was that the diameter of pinhole that I was using was about two time too big, it should be about 0.25mm. I had several attempts at making a pinhole lens with this diameter, and eventually succeeded having again resorted to the internet for suggestions (my favorite involves a deconstructed cola can, ultrafine oxide paper and a small pin, which is used to barely prick the metal).

I ran a black and white film through a SLR using various pinhole lenses (a 0.25, 0.4 and 0.5mm) and a normal 50mm glass lens. I developed and printed the film and found that the 0.25mm pinhole gave by far the best results in terms of pinholes.

Above Diggle captured with:
        a 50mm Lensed camera:

                a 0.25mm pinhole