NBS Special Publication 374
Method for Determining the Resolving Power of Photographic Lenses
(1973)

Contents

• Introduction
• Front Cover (red and white in original)
• Inside Front Cover omitted (Description of the NBS)
• [p. i] (Title Page)
• [p. ii] (Cataloging Page)
• p. iii (Foreword)
• p. iv (Contents)
• p. 1 (Abstract, Introduction)
• p. 2 (Choice of Criterion for Judging a Lens, Speed of a Lens as a Criterion)
• p. 3 (Quality of Definition as a Criterion)
• p. 4 (Significance of a Resolving-Power Test, Charts for Testing Resolving Power)
• p. 5 ([Illustration of NBS Test Chart from Circular 428 (1930s)], NBS Resolution Test Chart of 1952)
• p. 6, p. 7, p. 8, p. 9
• p. 10 (Details of Camera Test)
• p. 11, p. 12, p. 13, p. 14, p. 15, p. 16, p. 17
• p. 18 (Interpretation of Results)
• p. 19, p. 20, p. 21, p. 22, p. 23, p. 24
• p. 25 (Additional Uses of Test Chart)
• p. 26
• p. 27 (References)
• p. 28 (Appendix: NBS Microcopy Resolution Test Charts No. 1010a)
• Inside Back Cover (Bibliographic Data Sheet; red and white in original)
• Back Cover omitted (List of Selected NBS Publications)

Lens Resolution Test Chart Sets (1952) To Accompany NBS SP 374

• Lens Resolution Chart set 1 (high-contrast), low-resolution image (0.5 Megabytes)
• Lens Resolution Chart set 2 (low-contrast), low-resolution image (0.6 Megabytes)
• Upper Left Chart from Lens Resolution Chart set 1 (high-contrast), full-resolution (1,200 dpi) image (1.6 Megabytes)
• 1,000 x 1,000 pixel version of the above Chart (124 Kilobytes)
• 500 x 500 pixel version of the above Chart (36 Kilobytes)

Introduction

This is a reprint, in the form of scanned images, of US National Bureau of Standards (NBS) Special Publication 374, Method for Determining the Resolving Power of Photographic Lenses (June 1973), by Francis E. Washer, Irvine C. Gardner, and C. E. Kuyatt. It includes low-resolution images of Lens Resolution Chart set 1 (high-contrast) and Lens Resolution Chart set 2 (low-contrast) and a full-resolution (1,200 dpi, but lossy JPG) scan of one chart from Chart set 1, but these scans simply illustrate these charts and are not appropriate substitutes for real, properly prepared, test charts. 1,200 dpi scans of these chart sets run to many Megabytes and are too large for inclusion here. The methods of lens testing described here are no longer considered current, as this paper's authors point out in their Foreword.

The full image of Lens Resolution Chart set 1 (high-contrast) was produced by scanning an original at 1,200dpi in 8-bit greyscale with a machinist's millimeter rule in the image. This scan was 9,480 x 12,769 pixels and occupied 43 Megabytes as a (lossless) PNG file. This was scaled to 2,000 x 2,694 pixels and converted from PNG to (lossy) JPG in The GIMP, resulting in an image of 0.5 Megabytes. This JPG file is the one presented here. The scan of Lens Resolution Chart set 2 (low-contrast) was done in the same way, and resulted in a PNG image of the same dimensions (9,480 x 12,769) but slightly smaller file size (50 Megabytes). Scaled to 2,000 x 2,715 and converted to JPG, the resulting image file was, curiously, slightly larger (0.6 Megabytes).

The image of a single chart or element from the Chart set 1 (high-contrast) is of the upper left element in the Chart set. It was taken from the original 1,200 dpi scan, cropped manually to 4,200 x 4,200 (file size at this point 6.5 Megabytes) and then converted to (lossy) JPG for a final file size of 1.6 Megabytes. At the time of preparation (the year 2004), this is still a very large file to put online.

Two smaller (and thus more easily viewed) versions of this image were then prepared from it by rotating it 90 degrees so that its text read horizontally and then scaling it to 1,000 x 1,000 pixels (124 Kilobytes as a JPG) and 500 x 500 pixels (36 Kilobytes as a JPG).

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