Digital Photographer's Software Guide - Bertemes - Net

Many people who upgrade to a Digital Single Lens Reflex (DSLR) camera from a pointand-shoot
camera are disappointed to find that the images appear less sharp. The reason
for this phenomenon (the lack of sharpness, not the disappointment) is because pointand-shoot
cameras impose a greater degree of sharpening as a matter of course. DSLRs
give you a choice of whether to use the manufacturer’s routines or carry out the process
yourself on a computer. The latter is by far the better approach, especially with today’s
excellent choice of sharpening software.
What Is Sharpness?
16
Sharpening Software
In digital photography, sharpness is essentially a combination of acutance and resolution,
the first being mainly a function of the lens and the second a function of the sensor.
The two concepts are closely interlinked, but acutance relates to edge contrast—to
the boundaries between areas of different tones or colors—whereas resolution relates
to overall detail.
Pixel resolution is the overriding factor in sharpness, but contrast comes second, with
uniform noise a distant third. Because the human visual system pays particular attention
to the edges of objects, this is where we are most likely to notice any lack of sharpness
in a photograph. Sharpening software concentrates on the edges, trying to make them
absolutely distinct.