An MTF Analysis of the Contribution of Motion-Picture Printing to Image Sharpness

John C. Norris

The image sharpness of motion-picture release prints depends not only on the film products in the system, but also on the capability of motion-picture printers to transfer images. As sharper films become available the need increases to know the transfer characteristics of other system components. Modulation Transfer Functions (MTF) have been used to analyze the performance of various films and printers in the Eastman Color super-8 optical release system. — Use of MTF techniques permits one to compute apparent transfer functions for various printing stages and conditions, including step optical, continuous optical, and continuous contact types. The continuous optical and step optical printer transfer were found to be similar at best focus. The continuous contact printer carefully adjusted and maintained resulted in print-through MTF, in the normally viewed frequency region, significantly close to the theoretical limits of 100% transfer for contact printing. However, poor contact adjustment and poor focus yield low print-through transfer characteristics and noticeably unsharp prints. Especially critical is focus in an optical reduction printer. Printing out of focus by as little as 0.002 in can perceptibly degrade super-8 print sharpness.

Print ISSN
Published
1970-08
Content type
Original Research
DOI
10.5594/J00887