I always understood in theory, what was happening with curves, but I never
could apply it. Your bottom paragraph pretty much sums up what you can use
from the zone system with color transparency and digital cameras. While
that might seem limited to what you can do with black and white, how many of
us shoot with a view camera. Even with that much information, you are still
light years ahead of a point and shoot users. I have even done zone tests,
and then shot with an incident light meter, knowing that zone 5 would be
dead on, and that clipping would take place at either ends.
As for crossover, I know there is a tendancy to wards greenish blacks, and I
use flash fill as needed.
I am not sure that I agree with the numbers that your pro friend came up
with. But remember, we are talking about a system that includes your
camera, your film, and your lab. I just know what works for me.
----- Original Message -----
From: "Julian Robinson" <jrobinso@pcug.org.au>
To: <filmscanners@halftone.co.uk>
Sent: Friday, November 23, 2001 1:25 AM
Subject: Re: filmscanners: Negs vs slides again: was Color Negative Film
Poll
> That's interesting - I got my figures by looking at the characteristic
> curves of some Kodak films - see for example
>
> (royal gold 400) and comparing with some slide film - see for example
>
> (PROFESSIONAL EKTACHROME Film E100VS).
>
> I looked at the characteristic curves, and the exposure density range on
> the bottom axis corresponding to a more-or-less linear part of the
> curve. For slides I got a density range (log) about 1.6 and for negs
> around 3.3 corresponding to just over 5 stops and 11 stops respectively.
>
> Perhaps in your measurements you went beyond the linear part of the curve,
> which is valid if you can still see the difference. This fits with the
> given curve because 7 stops corresponds to a log density range of 2,1
which
> is in fact the range given on the curve when you include the more curved
> parts at the end. You should have noticed some compression at the limits,
> and from the curve I am looking at, a tendency to red at the extreme dark
end.
>
> On the same basis you'd get 12 stops out of neg film.
>
> I was told at my recent classes by a "pro" that slides had a range of 4
> stops, and negs 7 stops which are the figures he used in his zone
> thinking. Perhaps he was being conservative and allowing for inaccurate
> exposure.
>
> I cheerfully admit to not really understanding the zone system, but I can
> well understand the simple concept of a 5, 7, ... 11 stop range and how to
> fit what you want out of a particular high contrast scene onto your film
> with a spot meter.
>
> Julian
>
