On 2013.03.20 19:17 , Doug McDonald wrote:
On 3/20/2013 4:33 PM, Alan Browne wrote: On 2013.03.18 20:09 , Doug
McDonald wrote:

I posted this because I was truly amazed at how bad it was. For normal
scenes its a non-issue.

Recall that you put up these images to refute the idea that lenses at
some point can't deliver detail to the ever increasing density of
sensors.

In reply to me stating that lenses behaved as spatial f filters as
sensor densities got higher,

You said: "Absurd: I own an 18 mpixel Canon7D, a crop frame
camera: and it shows bad moire on subjects like an LCD
TV. And it has an AA filter."

Your photos only illustrate a grid interference pattern. Nothing to to
at all with decreased resolution due to a lens and high sensor
densities. Nothing to do with AA filters either, to put a point on it.


You are wrong. Moire IS a "grid interference pattern". The frequency of

No **** Sherlock.

You're completely ignoring the point about lens _MTF_ which is what I
referred to before your "absurd" statement.

the patterns in this instance are those of the sensor (the green
spacing) and the spacing of the individual RGB pixels (i.e. three camera
pixels to one RGB triple).

Yes - as I clearly stated a couple posts ago - and still having NOTHING
TO DO with MTF which will soften detail to the pixel level as pixel
densities go up.

That is _WHY_ the DXO test referenced by the poster ("Me") showed LESS
resolution gain than pixel counts themselves would indicate.


The pictures show CONCLUSIVELY that the lens is fully adequate to
resolve adjacent pixels, and that the AA filer is NOT seriously smearing
out the image enough to stop moire.

If the AA smeared it enough to remove the moiré that you captured in
your contrivation, then you would be just as happy with the detail of a
6 Mpix camera. Probably not even then.


--
"There were, unfortunately, no great principles on which parties
were divided – politics became a mere struggle for office."
-Sir John A. Macdonald