Printer Resolution Test Procedures
Rev. 12 Sept. 2003 -by Jack Yeazel
(Background)
TEST TARGET - PIMA/ISO Resolution Test Chart to Test Digital Cameras http://www.edmundoptics.com/IOD/DisplayProduct.cfm?productid=2287 This 200 x 356 mm target (about as big as legal-size paper) costs $150!

The procedure to test a digital camera  is to frame the target exactly with its height.  You read the chart and multiply the number seen on the chart at the resolution limit by 100.  This will give you the LW/PH (Line Widths/Picture Height) resolution and is the method used in all the digital cameras review web sites.  A professional camera might resolves about 1,600 LW/PH (8 LW/mm of the 200mm-high chart).  Printing this on 8x10 (inches) paper should not be a problem for most modern printers.  The challenge comes when trying to print this resolution on 5x7 paper and retaining all the picture detail.  This would require the printer to print at about 13 LW/mm.

(Scanners)
In the process of looking for a 35mm film scanner, I noticed http://www.imaging-resource.com/SCAN/FS4000/FS40PICS.HTM where there is a very good and EXPENSIVE Canon scanner.  At the bottom of the sample pictures is a scanned image of the ISO resolution chart: http://www.gpsinformation.org/jack/photo-test/pics/iso-rag.jpg  This file has been adjusted, so that it prints out at the exact same "height" as the original.  With this chart you can do your own camera resolutions testing.
See: http://www.gpsinformation.org/jack/photo-test/pics/lens-tests.html for instructions.

The originally scanned image has a green cast between the lines (near "20").  I'm sure the original has perfectly white spaces between ALL lines, that's why it costs $150!.  (The 800mm version of this chart costs $845).  Thus, the chart below has been extensively "tweaked" to provide the greatest clarity between lines.

(Printers)
PIMA/ISO Target Used to Test Printer Resolution
After downloading the above chart, I experimented with printing it.  The most demanding point on the chart is at the "resolution" number "20" which is 10 LW/mm.  Most modern printers have no trouble printing that resolution on 8x10 (inches) paper.  In order to develop a more stringent test of a printer printing digital photos at 5x7, I "doubled" the resolution of the (2.2MB) file below to 955 ppi (pixels per inch) to make the chart exactly 100mm "high"  as measured between the four indexing "arrowheads" at the top and bottom.

This gives the printed chart's resolution numbers a direct 1-to-1 relationship to LW/mm, so that at "20" there are 20 Line Widths/mm (or 10 Lines/mm -with the older terminology.)  I know of no printers that will print that resolution for both the horizontal and vertical lines, so the actual resolution will be at smaller numbers.  This chart should be within the range to test a printer's ability to do 'professional' work at 5x7 -the approximate size of these pictures.

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Test Images:  PIMA/ISO Chart                              Photo with lots of Detail
Left-click on these images and download them to a file

Print: http://www.gpsinformation.org/jack/iso-gd-cb-955s.jpg with something like Photoshop.  Do nothing to the file, it should be about 4x6 inches.  Time the print from when the printer first starts to move.
Then print: http://www.gpsinformation.org/jack/pots-f4.5s.jpg This should be about 4.5x6".

NOTES:
The older terminology of resolution was lines per mm (L/mm).  To get L/mm, divide your results by 2 (2LW/mm=1L/mm).
The limit of human vision is about 20 LWL/mm (or 10 L/mm) -the highest resolution of the test chart.

Go to the Results Page: