The Sharpness Indicator

Ivan Putora wrote this paper as a thesis at one of Czechoslovakia's official film schools. He was, obviously, unaware of the existence of a very interesting paper by Dwin R. Craig, titled “Image Sharpness Meter” and published in Photographic Science and Engineering, vol. 5, pp. 337–342, Nov.-Dec. 1961. It is interesting to note that both authors treat precisely the same matter, although in a slightly different way. Whereas Craig, starting from the same premises, develops an instrument for the direct measurement of best focus by purely photometrical means, Putora attempts to develop a comparison method, based on the same principle as that of Craig, but which can be employed in a general way for evaluating optical systems and/or photographic or TV-camera performance, either by eye or by instrument. Whereas Craig's method uses, as a starting point, focus measurements on enlarger easels, Putora's initial effort is directed at motion-picture camera focusing. We believe it will be of interest for the Journal readers to compare both authors' lines of thought and to draw their own conclusions. Putora's merit is, perhaps, to give a method that appears to be very simple in its applications, and to have it based on the customary sensitometric representations and calculations for image evaluation.—P.W.-T.

Print ISSN

0361-4573

Published

1969-11

Content type

Original Research

DOI

10.5594/J10781