0.15mm pinhole aperture mounted in a 3/4 holder or 19mm in diameter. This is the perfect size for a wide angle camera. You have to figure out a way to mount this in a body cap. The optimum focal distance is in the 17mm range. The closer to the sensor or film plane the winder the angle.
This pinhole is mounted into an aluminum holder is 0.6mm thick and the pinhole is 0.05mm or only .002 of an inch thick. These pinholes are outstanding and unrivaled quality due to the thinness of the pinhole and the perfect forming of the aperture using the most advanced methods. 
Most people will mount these in a camera body cap, digital or film. You could also build your own camera around this pinhole out of something as simple as a cardboard box.

These are scientific grade apertures and have been utilized by universities and laboratories. The second photo shows the pinhole at 800x under the microscope.
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