A photograph of the beatification ceremony published in the Washington Post provided an unusual opportunity to confirm the reported number, first because of the level of detail it shows, and second because maps of the area are available to use in correcting for the foreshortening distortion in the picture. I conclude that there are about 105,000 people shown in the photograph, or less than one half the number handed down to us by the press. Below, I show step by step how I arrived at that figure.

Scanned-in photo from the print edition of the Washington Post, Oct. 20, 2003. (The counting for the estimate was made using the print version.) Full-resolution image .

A section of the audience within the white rectangle is seated in an array of about 20 columns across and 40 rows deep. ( Enlarged detail . If we conservatively use 1000 as the number of people within the rectangle...

...and multiply by ten, the number of similar sections within the foreground area bounded by the white line in this photo...

...then there appears to be 10,000 people in an area that we can relate to the total area of St. Peter's Square using this diagram. The area is within the black trapezoid. Using a Full size image, some tracing paper and graph paper, we can determine that it is about one eighth...

...of the area within the white line in this image. Therefore there are about 80,000 people within St. Pater's Square. It remains to determine the area in the rear beyond the square. Assuming that the windows in the side buildings are spaced the same as those in the building going across, we can estimate that it has an area large enough to contain an additional 25,000 people. Therefore this photo shows a crowd of about 105,000.