[Tig] Is there anybody out there

[Adrian Thomas]

The 'problem' with film is that it behaves so oddly at the extremes  
that it hardly seems fair to describe those as part of the dynamic  
range. How on Earth would you quantify the effect of solarisation,  
for example? When I worked as a newspaper photographer, one of my  
favourite techniques was that of 'dilute development' to effectively  
'push' the film speed of my Ilford HP5. The benefit of this technique  
(long, cool, dilute development stage) was high effective film speed  
without increased grain, the drawbacks were EXTREMELY thin negs and a  
very non-linear tone curve - you were operating entirely in the low  
toe of the response. With the kind of elastic tonal response you can  
get from film, simply stating that it has such-and-such a dynamic  
range or resolution is hugely misleading, and I feel we really ought  
to confine such metrics within strict operating parameters else they  
become meaningless as a means of comparison.

Anyway, film is pretty much binary in terms of tonal response when it  
comes right down to it, everything else is up to how you develop that  
binary latent image...

--
Adrian Thomas
Automatic Television
35 Bedfordbury
London WC2N 4DU
www.autotv.co.uk
--


On 3 Aug 2006, at 12:07, Peter Swinson wrote:

> I always question the term dynamic range with film vs video.
> Consider this. Dynamic range is quoted as max vs min density, light  
> level,
> whatever. It could be argued that a 1 bit system has extreme  
> dynamic range
> 0=the sun, 1=the deepest coal mine. Even so I believe the non linear
> portion of the film range is significant, especially when manipulating
> images in a grading suite.
> What I regard as the advantage of dynamic range of film is the  
> other end of
> the scale. Film can distinguish very very small changes in shade.  
> Now I
> know the scream 10, 12, 14, or 16 bit will go up. BUT, the bit  
> depth does
> not take the granular stochastic resonance into acount whereas our  
> visual
> systems do. This to me is what gives film its apparent ability to  
> preserve
> and provide a greater subtlety of texture. This remains even when
> transferred to digital media, as long as trhe grain is not heavily  
> removed.