Hello all
I have been lurking for a while now but be very interested in the
technical aspects of scanning. With the help of on of the URLs given I
found this article <> which
is written in a way where even I understand it (which means everyone
else will too)
Greetings
Theo from downunder
shAf wrote:
>
> Tom writes ...
>
> > ...
> > It's something with the way monitors show images, but what exactly
> is it??
> > I notice that my scanner software has a gamma adjustment and playing
> with
> > it I noticed that it changes the way the image appear on the screen.
>
> More than monitors, most devices have a specific gamma associated
> with them ... scanners, printers, digital cameras.
>
> > But what exactly is this mysterious gamma thing?
>
> Each device has an associated "black" and "white", both of which
> are generally similar across all devices (forget for now the color of
> white, eg warm vs cold). Between black and white however, is how a
> device responds to the data (eg, monitor), or its stimulation by light
> (eg, camera+film). This response is generally refered to as the
> device's "gamma".
> This type of response is complex, but can be simplified and
> modeled by a mathematical power function ... the gammas we all refer
> to as (eg) 1.8, or 2.2, even 1.4 are exponents of this power function
> called gamma.
>
> > My scanner software defaults to gamma=1.4. It this an optimal value?
> If
> > not, what is a better value?
>
> It may indeed be your scanner's optimal value ... like I said,
> each device has its own. However, don't let the math intimidate you.
> The important parameters to first understand are "black" and "white"
> ... if everything inbetween looks good, then your gamma is probably ok
> too. To get it perfect ...
>
> further reading:
> Charles Poynton's color and gamma FAQ:
>
>
> If you use Photoshop:
> "Basic Color Theory for the Desktop"
>
>
> nighttime reading:
> Bruce Fraser's "Real World Photoshop"
>
> shAf :o)
