Abstract: A method and apparatus for sputtering coatings on substrates in very high vacuum conditions is shown where the high vacuum is made possible by a supply of inert gas localized at the sputtering source and confined by velocity and by physical constraints in the area of the source and is depleted as the inert gas flows into a larger vacuum chamber. Additional methods to improve testing of substrates being coated and to enhance the sputtering process by use of ion gun directed reactant toward the substrates are disclosed. The method and apparatus are especially effective in allowing large spacing between source and substrates in the sputtering process. The large spacing provides good coating uniformity on large substrates.