Digital Photo Printing
It's all in the details !
Consider the obvious viewing extremes:
At some viewing distance:
- If you look at a digital print with a loupe magnifier you can distinguish
the printer dots.
- If you look at the same print at a distance, you may not be able to
distinguish individual pixels so you could have printed it larger.
Finding a reference viewing distance:
- Individual pixels will be just recognizable as pixels and ...
- The color of every pixel will be a precise as the eye can distinguish --
within the color gamut limits of the printer, of course.
- The "Golden Ratio", 1.618, appears often in literature related to artwork
which makes it an ideal candidate for photography.
- 1.618 represents an esthetically pleasing dimentional ratio
between two related distances found in nature. [(a+b)/a = a/b]. The 40D
sensor, having the same aspect ratio as 35mm film, would be close;
(3888+2592)/3888 = 1.666 and 3888/2592 = 1.500. However, the importance
atributed to this ratio may be of more usefulness than the value itself
since the exact ratios in nature are generally only close to this value.
- For photographic prints of 3:2 aspect ratio, like 35mm film, a 13x19 print
has an area of 247 sq-in; equivalent to a square of 15.7 inches on a side
with a diagonal of about 22 inches. Using the Golden Ratio of 1.6 for this
13x19 print gives about 25 inches. How convenient!
- To make things even more convenient, let's just use the actual diagonal
of a print (here 13x19 gives about 23 inches) as the viewing distance. So,
it is not a surprise to find comments on the internet that the diagonal
measure of a print to be the recommended viewing distance.