----------------------------<included message follows>------------------
> From: petermarshall@cix.compulink.co.uk (Peter Marshall)
> Date: Sat, 25 May 96 11:31 BST-1
> Subject: Re: The Aesthetics of Paper
In-Reply-To: <memo.656282@cix.compulink.co.uk>
At the risk of repeating myself - my mail system is playing up and also
either Terry is suffering from OLR lag or some other problem.
1. The basic laws of sensitrometry apply to all photographic processes.
There is no point syaing 'but we are not talking about silver gelatine'
- and it is untrue in any case unless you have gone over completely to
digital in making your negatives.
2. The number of steps reproduced when you print a step wedge only gives
you information about the appropriate density range of the NEGATIVE
required for the process under the conditions used.
3. NO information about the tonal range of the print can be inferred
from the number of steps reproduced. To get this you need to measure the
densities of the steps on the print - either quantitatively using a
densitometer or on a very rough basis by visual comparision with a
calibrated print. The tonal range can be _exactly the same_ for a print
with 5 steps or a print with 15 steps.
I'm going to repeat that so no one is left in any doubt. NO information
about the tonal range can be inferred from the number of steps
reproduced.
4. Finally, on the question of comparing eye and film rather than
continuing a futile argument I suggest anyone who is interested either
reads the odd book or tries a practical test.
Peter