LaserSoft Imaging Newsletter November2005 auf Deutsch lesen
Dynamic Range of all scanners significantly enhanced!
SilverFast's Multi-Sampling brings Scanners to a new Level of Quality
Dear SilverFast User,
SilverFast Ai STUDIO and SilverFast SE Plus supply the most dramatic boost in quality to scanners with SilverFast's patent pending Multi-Sampling with Auto-Alignment.
What differentiates a very expensive high-end scanner, such as drum- or Linotype-Hell or Scitex Flatbed scanner,
is the low noise of these scanners due to cooling of CCD and other constructive methods.
When a scanner has very low CCD-noise so much more Unsharp Masking can be applied.
That is the main reason that high-end scanners deliver very sharp and brilliant scans.
User Comment:
The new multisampling feature in SF Studio appears in my testing to be a real breakthrough.
.. It would be hard to surpass the noise reduction of SF Studio.
My tests also reveal that with SF Studio you get the most noise reduction in RGB files (noise is virtually eliminated
completely) even if you are looking for a grayscale image as the final product.
So I am scanning 4x5 b & w negs as 48bit RGB files with 16 sampling passes and then converting them to 16 bit grayscale.
The exact opposite was true with former SF AI 6.
You would get much less noise with grayscale scans with SF AI 6.
Kirk Gittings
Read here how SilverFast's phenomenal Multi-Sampling is working:
Dynamic Range Increase with SilverFast Multi-Sampling
We have measured the Dynamic Range increase according to the new upcoming ISO standard
ISO 21550
and as you can see in the diagram below, SilverFast's Multi-Sampling yields dramatic improvement for scanner Dynamic Range.
It is interesting to see that even for scanners that already have Multi-Sampling built into
their hardware such as the Nikon LS5000, there is a significant increase in Dynamic Range from 2.9 to 3.4.
That exemplifies the unique quality of SilverFast's Multi-Sampling process.
Upgrade to SilverFast SE PLUS:
https://www.silverfast.com/show/silverfast-seplus/en.html
Upgrade to SilverFast Ai STUDIO:
https://www.silverfast.com/show/silverfast-ai-studio/en.html
What is DMAX, Dynamic Range and Density?
Image density
is measured from image brightness with optical densiometers, and ranges from 0 to 4, where 0 is pure white and
4 is very black. More density is less brightness. Density is measured on a logarithmic scale.
Density of 3.0 is 10 times greater intensity than a density of 2.0. An intensity range of 100:1 is a density of 2.0,
and 1000:1 is a density of 3.0.
Density
4.0 (which is 10.000:1) is not a theoretical maximum, the math is not limited, but it is a practical maximum of density,
because almost nothing you can scan will reach 4.0.
The minimum and maximum values of density capable of being captured by a specific scanner are called
DMin
and
DMax
. If the scanner's DMin were 0.2 and DMax were 3.1, its Dynamic Range would be 2.9. DMax implies unique image tone
values are distinguishable, and not hidden by electronic noise. Greater dynamic range can detect greater
image detail in dark shadow areas of the photographic image, because the range is extended at the black end.
DMAX
is a value describing how much light variations an input device can differentiate.
In general manufacturers publish a value that does not relate to the true usable maximum dynamic range, instead it is
a theoretical value. When a scanner can still see light variations such as in the shadows of a scan but the
CCD already produces visible noise rendering the scan unusable.
So briefly speaking DMAX is the maximum density a scanner can detect, while
Dynamic Range
is the usable range of shades a scanner can differentiate.
SilverFast Official Guide Book explains it all!
Your Key to Better Scans, Beautiful Images, and Improved Efficiency
https://www.silverfast.com/show/sf-official-guide/en.html
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