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Old 09-25-2014, 09:42 AM   #90
ApK
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Wait a sec, this is driving me batty:

Quote:
Originally Posted by dsmid View Post
167 ppi * 6 inches = 1000 pixels diagonally
and 800^2 + 600^2 = 1000^2 according to good old Pythagoras
The problem with that is you first calculate a result of 1000 by ASSUMING 167 dpi for the diagonal. Then you are using that result in the theorem as a given, but it's only based on your assumption in the first place.

The problem with using the Pythagorean theorem for diagonal dpi, is that the theorem uses scalar units that would measure the same in any direction. Pixels are in fixed positions in a matrix, so you can't equate them with scalar units like inches. You will count a different number of them per inch depending on the angle you measure them on.

I think, after going back and forth a few times, that DT is right.
And nomenclature-wise, where has any manufacture used the term "diagonal dpi?"

Last edited by ApK; 09-25-2014 at 10:40 AM. Reason: No more editing now! Right or wrong, I'm sticking with this response!
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