Re: VueScan: (was: Re: Measuring DMAX

[Yves Gauvreau <gauvreau-yves@cgocable.ca>]

Hi,

for those with unequal values and for those who just need an approximate
value you could use the green density * 0.95 + the blue value * 0.30 + the
red value * 0.15.

These factors are based on the visual photopic luminous efficiency function
or if you prefer the (ISO) filter used by densitometers to give us the
visual density.

Yves

----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, February 01, 2008 12:45 PM
Subject: Re: VueScan: (was: Re: Measuring DMAX


>
> On Feb 1, 2008, at 8:46 AM, Katharine Thayer wrote:
>
> > Thanks, but not true; my three numbers are all different; I've
> > never gotten three identical numbers, either in 8 bit or 16 bit, or
> > even in 1 bit! They generally range over 6 or 8  points, but
> > sometimes as much as 12 or 15.
>
>
>