Make Your Own Digital Camera ISO Test Target

"""
dpnow writes I run a digital photography site and came across what I
thought might be an interesting story. It's about a Cornell university
researcher that has reverse-engineered the design of the ISO 12233
resolution test target, used by all the best digital camera testers.
These usually cost over $100 but a free pdf download of the target is
available. Print it out on a good quality printer and you have your own
ISO-spec test target so you can find out how good (or bad) your camera
really is!
"""

http://slashdot.org/articles/04/10/18/1127252.shtml?tid=126&tid=159&tid=1

 

If you want an ISO 12233 chart to play with, and don't want to pay big
bux, the Westin chart seems to have a problem printing out -- but
another such creation is available.

I have a theory (still trying to test it) that Westin's file is
intentionally (by someone) crippled-- that it contains an instruction
to print at low resolution. (He hasn't yet replied to my email.)

The chart file at ISO headquarters' website is 611K in size.
Westin's file is 211K, which would lead you to wonder how such low-res
instructions could fit. My answer: First, the original 611K file
probably has lots of extra instructions, like "don't let yourself be
copied or emailed." PDF files can contain Javascript and lots of other
languages that Adobe Reader understands.

Second, I have found on the web ANOTHER 12233 file, a PDF of only
93K. It looks a lot like Westin's file, same typefaces (different from
the ISO original, see the "6" digits), without the Westin credit line
at bottom. It has not quite the same spacing anomalies as Westin-- see
the 4's and the 5's at left center. I am scouting around to find
someone to print the file full (15.75"x9.45") size-- or double size,
since I have downloaded some Chinese software which can enlarge a PDF.

My theory is that the smaller file lacks all of the sneaky crippling
instructions, and will cheerfully print at the full resolution of the
chosen printer. On little letter-size inkjets, even the Westin file and
my enlargements of it print at full 600dpi resolution, but only the
center tile (circle-in-square plus the smaller parts of the
flaring-parallel-line wedges). My thinking is that the smaller inkjets
are not smart enough to hear the Westin file saying (via Adobe) to
print at low resolution. Printing five or more of these centers, trying
for inkjet on glossy (better contrast, just light them from the side),
and pasting them around a big piece of cardboard, will be my "cope"
until I find a PDF full chart that will print as well as the selected
printer can perform.

If you want a copy of the mysterious 93K file to play with, give me
a buzz at and I'll email it to you. Just promise me
that you'll post your test results somewhere soon (I have no website).

http://slashdot.org/articles/04/10/18/1127252.shtml?tid=126&tid=159&tid=1

 

I downloaded the PDF file
(http://www.graphics.cornell.edu/~westin/misc/res-chart.html) and printed it out on
my Canon s9000 A3 printer. The printer seems to be the limiting factor as detail is
clearly visible on the PDF file. Aliasing on the resolution wedges limits the
charts useful resolution to about 1200 lines.
I'd be interested to know if anyone has had any better results and if so how?
There's some useful information about this (but somewhat inconclusive) available at
http://new.dpnow.com/1263.html.

Regards
Peter.


If you want an ISO 12233 chart to play with, and don't want to pay big
bux, the Westin chart seems to have a problem printing out -- but
another such creation is available.

I have a theory (still trying to test it) that Westin's file is
intentionally (by someone) crippled-- that it contains an instruction
to print at low resolution. (He hasn't yet replied to my email.)

The chart file at ISO headquarters' website is 611K in size.
Westin's file is 211K, which would lead you to wonder how such low-res
instructions could fit. My answer: First, the original 611K file
probably has lots of extra instructions, like "don't let yourself be
copied or emailed." PDF files can contain Javascript and lots of other
languages that Adobe Reader understands.

Second, I have found on the web ANOTHER 12233 file, a PDF of only
93K. It looks a lot like Westin's file, same typefaces (different from
the ISO original, see the "6" digits), without the Westin credit line
at bottom. It has not quite the same spacing anomalies as Westin-- see
the 4's and the 5's at left center. I am scouting around to find
someone to print the file full (15.75"x9.45") size-- or double size,
since I have downloaded some Chinese software which can enlarge a PDF.

My theory is that the smaller file lacks all of the sneaky crippling
instructions, and will cheerfully print at the full resolution of the
chosen printer. On little letter-size inkjets, even the Westin file and
my enlargements of it print at full 600dpi resolution, but only the
center tile (circle-in-square plus the smaller parts of the
flaring-parallel-line wedges). My thinking is that the smaller inkjets
are not smart enough to hear the Westin file saying (via Adobe) to
print at low resolution. Printing five or more of these centers, trying
for inkjet on glossy (better contrast, just light them from the side),
and pasting them around a big piece of cardboard, will be my "cope"
until I find a PDF full chart that will print as well as the selected
printer can perform.

If you want a copy of the mysterious 93K file to play with, give me
a buzz at and I'll email it to you. Just promise me
that you'll post your test results somewhere soon (I have no website).

http://slashdot.org/articles/04/10/18/1127252.shtml?tid=126&tid=159&tid=1

 

I had it printed out on a d-lab 2 at 12x18" and it still wasn't really
too useful, I suspect it really needs to be printed on an offset press.
I was thinking that it could be contact printed in small quantities
using a neg produced from a high res imagesetter too?

Cheers,

Rob