The pinhole, the simplest of lenses in the sense of a glassless aperture (depending on your definition of a lens) the pinhole effectively acts to converge light by an action analogous to that of an optical glass lens.
The lens in this case was basically, aluminium adhesive tape over a spare lens converter with a tiny pin hole (~ 0.5 mm diameter). Exposure will be relatively very long, in this case about 6 seconds at 800 iso. Subject obviously, needs to stay still for a relatively sharp image, but as you can see, I've quickly changed my position half way though exposure to get two images of myself, although somewhat transparent and ghostly. Although image quality is poor compared to a glass lens, it does have advantages in that depth of field is almost limitless, no need to focus, cheap (no glass lens required, just a few "Blue Peter" skills needed) and fun with great artistic license. I must try to forget about all my glass lenses and try more pinhole photography.
Owner: Gordon England