Filmgate Philips DP 70‏

The Philips DP70 is considered one of the most beautifully designed projectors ever. Dutch Philips’ engineer Jan Kotte has coupled a superb design with unequalled properties. is Never before an Oscar had been awarded to a film projector.

Obviously, with this design Mr. Kotte had to consider some technical characteristics of parts as supplied by third parties, such as projection lenses. The depth of focus of lenses at the time was rather limited. Therefore Mr. Kotte designed a flat area in the curved gate, exactly at the position of the image aperture so as to achieve the best overall sharpness of the image on the screen. The idea that the pressure bands would indeed flatten the film in this area has not proven to be correct. Actually it tends to create some adverse effect in the film during projection which is clearly visible. Modern lenses have a much improved depth of focus that negates the assumed necessity of having a flat area in the middle of the gate curvature. Rosbeek Engineering has developed a new film gate made of Delrin. This material was later also used by Mr. Kotte in other projectors, and replaced Tantung as used in the DP70/ Norelco AA. Tantung has the nasty habit of emulsion particles being allowed to build up and in doing so can cause damage to digital soundtracks. Delrin has intrinsic properties that prevent these build ups to a high degree.