Hej,
Jeg husker ikke, hvor jeg har dette link fra
http://www.luminous-landscape.com/tutorials/understanding-series/res-demyst.shtml
Det kan være fra NikonCoolpix gruppen på Yahoo, måske fra
rec.photo.digital - eller måske endda fra d.fritid.foto ???
Efter min mening gives der i de mange tutorials på siden mange
super-gode svar på spørgsmål, som også jævnligt drøftes hér.
Nedenstående er snippet fra ovenstående link, men der er meget godt at
hente på siderne. Prøv dem - hvis I ikke kender dem i forvejen!!
Se efter tutorials på hovedsiden, derefter i bunden af skemaet
tutorials med titlerne "Understanding...."
vh. Ole Rosted
bemærk de to sidste linier!
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Misconception #3: Resolution is expressed in megapixels
For the purpose of this article, resolution is defined as the
ability to distinguish (resolve) separate visual information such as
details and fine patterns. Traditionally, the measure of resolution is
described by the resolving power and is expressed in line pairs per
millimeter (lp/mm). It is evaluated from the ability to distinguish
distinct line patterns from standard test charts.
However, resolving power numbers (lp/mm) are a somewhat subjective
measure because each test administrator applies his or her own
judgment in identifying at which point a pattern can no longer be
distinguished. For this reason, no conclusions can be drawn from
resolution figures comparison from various sources or derived from
different methods but comparisons made under the same conditions and
evaluated by the same person do offer a comparison reference.
It should be noted however, that computerized methods to evaluate the
cut-off point of a distinguishable pattern are currently being tested
and proposed.
Images are two-dimensional objects. Therefore, doubling the resolving
power necessitates a fourfold increase in pixel (of equal quality) –
not a twofold increase as is
commonly believed. All else being equal, a 6 megapixel camera does
not have twice the resolving power of a 3 megapixel camera, but twice
that of a 1.5 megapixel camera.
To complicate matters further, several other factors affect
resolution. Some of the most important factors include sensor design,
interpolation algorithm, the lens itself, focal length (in the case of
zoom lenses), focus distance, aperture, position in the image field,
orientation (horizontal, vertical, and diagonal), scene contrast, and
vibrations. Due to the number of degrees of freedom, comparing two
camera’s megapixels rating would be absolutely pointless as described
later.