How many pixels?

I have read the article you reference and it is significantly at variance with
a correct reading of the one I cited earlier, so I have relied on the one
I cited because it matches up with my observations of human visual acuity.
Why don't you subject your conclusions to a test as I did, albeit a pretty
informal one?

In any case, I tire of our impasse, and do not plan to respond further.
I'll let the folks that follow our dialogue decide for themselves which
of us is correct.

--
When a hammer is your only tool, all problems begin to look like nails.

It depends on whose eye is looking at them, but it would be about 20,000,000 pixels for an 8 X 10 and more for a larger size print. On a screen, it wouldn't be possible to display anything close to that sharpness. My 16:10 aspect screen has 1.76 MP.
--
Steve McDonald
http://www.flickr.com/photos/22121562@N00/
http://www.vimeo.com/user458315/videos



http://video.yahoo.com/people/4019627

--
Canon A2E, Sony R1 & Panasonic TZ5

The article you sited eariler, the article I just cited and my calculations all agree.

--
Canon A2E, Sony R1 & Panasonic TZ5

The source I cited:

http://www.ndt-ed.org/EducationResources/CommunityCollege/PenetrantTest/Introduction/visualacuity.htm

concludes its presentation with the following paragraph:

"When visually inspecting an object for a defect such as a crack, the
distance (d) might be around 12 inches. This would be a comfortable
viewing distance. At 12 inches, the normal visual acuity of the human
eye is 0.00349 inch. What this means is that if you had alternating black
and white lines that were all 0.00349 inch wide, it would appear to most
people as a mass of solid gray."

From this it is quite clear that each of the lines in the line pair they are
discussing is 0.00349 inch wide. A pair of lines, one black and one white,
each having a width of 0.00349 inch is equivalent to two adjacent pixels
with a pixel density of 286.5 pixels per inch. (286.5 is derived by taking
the reciprocal of 0.00349, i.e., 1/0.00349). I do not think that their
concluding statement could be any clearer.

My position has been stated and I am done.

Let the viewers' decide which position best accords with reality.

--
When a hammer is your only tool, all problems begin to look like nails.

Do you think I could get away with needing half as many pixels?

BG
--

Always open to learn something new - feel free to disagree with me any time as long as you can do it politely!!

You can get away even with 100 pixels. Your photos always look so great that the don't need pixels at all..

Cheers
Moti

--
http://www.pixpix.be

I have many excellent 1 meg images, which is the resolution of most monitors.
--
Canon A2E, Sony R1 & Panasonic TZ5

After "hijacking" this thread I got smart and did a Google search and learned that 56" is a good average size. I do agree that 42" is on the small side, however, we are watching a 32" regular TV now.