Re: So it's the bits? (Was: filmscanners: Sprintscan 120 nowon

[Tony Sleep]

On Fri, 12 Jan 2001 12:22:47 +1100  Julian Robinson ([EMAIL PROTECTED]) 
wrote:

 In other words number of 
 bits does NOT define Dmax, it only defines what the best possible might 
 be.

Odd, 'cos that was the point of the whole original argument :) IE that bit 
depth constrains maximum OD range in scanners where there is linear mapping of 
intensity. Which is pretty much all of the ones any of us use.

Regards 

Tony Sleep
http://www.halftone.co.uk - Online portfolio  exhibit; + film scanner info  
comparisons

Re: So it's the bits? (Was: filmscanners: Sprintscan 120 nowon B+H web

[Tony Sleep]

On Wed, 10 Jan 2001 23:16:57 +  photoscientia 
([EMAIL PROTECTED]) wrote:

 Oh no!
 Not this again.
 The answer is one word - linearity.

My reaction entirely :-)

Regards 

Tony Sleep
http://www.halftone.co.uk - Online portfolio  exhibit; + film scanner info  
comparisons

Re: So it's the bits? (Was: filmscanners: Sprintscan 120 nowon B+H web

[Julian Robinson]

  Oh no!
  Not this again.
  The answer is one word - linearity.

My reaction entirely :-)

But linearity explains only one half of the issue - that is, that you can't 
do BETTER for dynamic range than  what is implied by the number of 
bits.  Linearity doesn't make the most useful point that number of bits has 
NOTHING to do with the actual achieved density range performance when the 
noise level is the same as or more than the LSB.  In other words number of 
bits does NOT define Dmax, it only defines what the best possible might 
be.  I read most of the old "last time" posts and still didn't see any such 
useful conclusion.



Julian Robinson
in usually sunny, smog free Canberra, Australia

Re: So it's the bits? (Was: filmscanners: Sprintscan 120 nowon B+H web

[Robert E. Wright]

Finally!?
- Original Message -
From: Austin Franklin [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Thursday, January 11, 2001 5:59 PM
Subject: RE: So it's the bits? (Was: filmscanners: Sprintscan 120 nowon B+H
web



  In other words number of
  bits does NOT define Dmax, it only defines what the best possible might
  be.

 Absolutely correct!  It is but one piece of the system, and the system is
 only as good as its worst part.