[cliveh]

My best results are all 6x9cm, using a Zero Image camera which has a pinhole somewhat smaller than the recommended values calculated by pinhole designer. That makes the images a bit sharper, and the reduced enlargement from the film to the viewing size also helps it to appear sharper. Although, sharpness is not what pinholery is about. http://www.flickr.com/photos/9295972...7605483356905/

Try this for size - http://www.make-a-print.com/section462733.html