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[filmscanners] RE: Density vs Dynamic range
- To: lexa@www.lexa.ru
- Subject: [filmscanners] RE: Density vs Dynamic range
- From: "Shough, Dean" <dean.shough@lmco.com>
- Date: Mon, 10 Jun 2002 11:11:33 -0700
- Content-return: allowed
- Unsubscribe: mailto:listserver@halftone.co.uk
... I'd like to follow this through to a definitive source.
>
The proposed ISO standard on "Photography - Electronic scanners for
photographic images - Dynamic range measurements" (WD 21550.3 (42N 4909))
states that the dynamic range is calculated by:
DR = Dmax - Dmin
DR = Scanner dynamic range
Dmax = Density where the signal to noise ratio is 1
Dmin - Minimum density where the output signal of the luminance OECF
(opto-electronic conversion function) appears to be unclipped
They go on to define a standard method for defining the signal to noise
ratio using the concept of incremental gain. Incremental gain allows the
signal to noise ratio to be determined independent of gamma.
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