The Limits of Resolution

Feb 18, 2007 12:00:00 AM | Acrobat The Limits of Resolution

Discussion about the fact that Acrobat and other PDF viewer applications create drawing artifacts when PDF images are rendered to the screen.

by Mark Gavin

I’ve been developing an application to generate Fresnel Zone Plates; and, ran into an interesting problem.  A Zone Plate is similar to a lens in its ability to focus light.  It differs from a lens by using diffraction instead of refraction.

The problem I encountered is that Acrobat creates many significant drawing artifacts when it renders this PDF drawing to the screen.  In the above screen capture; only the rings centered on the center of the graphic are real.  All other rings, centered off of the center, are drawing artifacts.

ZonePlate_w_artifacts

A zone plate consists of a single set of concentric rings progressively getting thinner and closer together as they move out from the center. The application directly draws the rings of the zone plate to a PDF file as vector artwork. All of the other PDF viewing applications also introduce artifacts; but, they render these artifacts differently then Acrobat 8.

Following are links to a couple of PDF Zone Plate files to test in your favorite PDF viewer:

Zoneplate_128.pdf

Zoneplate_512.pdf

The appearance of the artifacts displayed will change as you alter the document magnification on the screen.

The intent of the application is to print the drawing to a wide format printer; then, photo-reduce the drawing onto a film negative in order to produce a zone plate.

Written By: Mark Gavin