Nikon D300 Complete Manual page 414

(If you want to know more about why this is, get The Manual
of Photography, 9
digital transformation is filled with mathematical concepts
and some pretty intimidating formulas).
The short version: If the frequency of detail in a scene is
higher than the sensor can sample, the detail is under-
sampled and combined into a single pixel (and sharp edges
tend to gather data from either side.) Sharpening uses contrast
adjustments at edge boundaries to trick our eyes into seeing
clearly defined edges.
While you might not have realized this, you've seen those
"beat" patterns before in this book:
Thom Hogan's Complete Guide to the Nikon D300
th
Edition. But be forewarned, analog-to-
V1.02
If the green dots
are photosites
on the sensor
and the black
lines high
contrast detail,
when a line falls
perfectly on a
photosite (top),
we get a perfect
rendering. If
some detail falls
on multiple
sensors (bottom)
the detail is
blurred.
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