Digital BW, The Print

Dana, I'm not following you. If the film is exposed and processed such
that it's density range is comfortable for the scanner, what
difference does the scene range really make, in this particular context?
I'm not a math guy...

The scene range could be 5 stops or 16 stops, and if one has materials
and process that can result in approximately equal film density range... ?
Am I making sense?

Tyler

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Dana H. Myers"
<dana.myers@...> wrote:
>
> David Whistance wrote:
> > 
> > 
> > I'm not sure where this comes from. 16 bits of data gives 2 to the
power of
> > 16 shades of grey, ie 65,536 of them. Should be plenty to divide by 17
> > stops, particularly as the relationship between a stop and a set
of shades
> > of grey is arbitrary - you can map them how you like with either
the scanner
> > software or Photoshop. What does surprise me is that Steve gets
this from
> > an Epson V700, however I've seen some of his images and he does
undoubtedly
> > capture a very large SBR with detail at both ends so I'm sure he's
right.
> 
> No one is questioning that David gets a tremendous SBR; it's the
> specific number that sounds too good to be true.
> 
> Dynamic range of a sample is limited to log-base-2(#levels).
> This is a theoretical limit; it assumes a perfect sampling
> chain.  Real-world performance is not going to be as good
> in general, there's a noise floor in the electronic chain,
> flare in the optics and limitations in the A/D converter itself.
> 
> So, in theory, the most that could be represented in a scan is
> 16 stops; practically speaking, it's probably more like 14 stops.
> 
> Cheers,
> Dana
>