The Process..

PANCRO's patented, high-vacuum process relates to the field of physics in the area of optics, which deals with the nature of light and image. PANCRO's investigations into this area have resulted in a scientific process and superior ND, which have been adapted to the field of cinematography and television.

In moments a single-piece optical-select glass is transformed into a neutral-density filter by skilled technicians using PANCRO's own patented high-vacuum process.

Glass is cut to size, clipped to a metal tray, hung in a large, steel vacuum system, and the door is securely shut with a heavy metal latch.

Air in the vacuum chamber is roughed out with large mechanical pumps.

Diffusion pumps are thrust open, synchronizing with mechanical pumps to achieve a high-vacuum similar to atmospheric pressure on the moon.

High voltage is introduced into the chamber and out gasses the high vacuum by an ionization identical to lightening in the earth's atmosphere. The electrical discharge breaks up gaseous molecules, removing them from the surface of the glass. The surface is prepared for good adhesion during the coating cycle.

When a high vacuum is achieved, a special metallic alloy is quickly evaporated at rapid speed and condenses tenaciously onto the surface of the glass in a specified uniform density of .3, .6, .9 or 1.2. and 1.5.

The chamber door is opened and the tray removed. The glass emerges as a PANCRO ND. The ND is not only superior in neutrality but durable and tough.