Pinhole Lens body cap for Pentax universal screw mount cameras. This mount was used on many camera brands like Praktica and Zenit. This pinhole lens can be used on just about any SLR or DSLR with an inexpensive adapter so if you have a Canon or Nikon you can take this from your classic film camera and shoot digital.
Compare prices, this is the highest quality at an affordable price so get creative and discover the amazing world of pinhole photography. Pinhole size is 0.3mm. This is the optimum size for this focal distance and provides the best sharpness, color saturation, and contrast. These are scientific grade apertures and have been utilized by universities and laboratories. The second photo shows the pinhole at 800x under the microscope.

The camera in the photo is to show the lens mounted and is not included in the auction