Susan wrote:
>
> Please translate! What is Dmax?
>
Just lifted this from www.scantips.com (a VERY useful site):
What is Dynamic Range?
Image density is measured from image brightness with optical densitometers,
and ranges from 0 to 4, where 0 is pure white and 4 is pure black. Less
brightness is more density. Density is measured on a logarithmic scale like
the Richter Scale, and density of 3.0 is 10 times greater than a value of
2.0. A intensity range of 100:1 is a density range of 2.0, and 1000:1 is a
range of 3.0. Nothing you can scan will be 4.0. The extreme values of
density capable of being captured by a specific scanner are called DMax and
DMin. If the scanner's DMin were 0.1 and DMax were 3.2, its Dynamic Range
would be 3.1. Greater Dynamic Range can show greater image detail in dark
shadow areas of the photographic image. Basically the range is extended at
the black end of the image.
When I say the "black end", I speak of positives, either prints or slides.
When images from negatives are reversed, this effect transfers to the
highlight tones. Most literature about 30 bits just says it improves
"shadows and highlights" without making this distinction.
A printed magazine image probably has a dynamic range well less than 2.0.
Photographic color prints might have a dynamic range of about 2.0. Film
negatives might have a range up near 2.8. Slides may go well over 3.2.
These are not precise numbers.
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