[Leica] thinking Zone System

[foto at marcdufour.net (Marc Dufour)]

Thanks for this, George.
I did a course about zone system, many years ago, and using analog 4x5.
Digital cameras and above all PS make it now so easier  ;-)
Marc

-----Mensaje original-----
De: lug-bounces+foto=marcdufour.net en leica-users.org
[mailto:lug-bounces+foto=marcdufour.net en leica-users.org] En nombre de 
George
Lottermoser
Enviado el: martes, 09 de noviembre de 2010 17:52
Para: Group Users Leica
Asunto: [Leica] thinking Zone System

Tarek,
When I shot film I used all formats:
sheets from 4x5 up to 12x20,
120 rolls from 6x6 to 6x9,
and of course 35 mm.
So I saw Zone System thinking, processing and testing as the way to achieve
predictable results with Black and White.
I use a spot meter to read the dynamic range of the subject; exposing for
the shadow detail I want to preserve; and developing for the highlight
detail I want to preserve; and then having a pretty good idea of where the
other tones will fall.
With 3 120 film backs I was able to carry an N, N-1 and N+1 back.
With 35 mm I'd carry two camera bodies - an N and N-1 body (and if exposing
an entire roll under the same dynamic range conditions I'd be able to
process accordingly ++ or - - or whatever).

Zone system thinking translates to color film as well.
Except only in terms of understanding the dynamic range of the film and
knowing how to expose for the highlight detail you wish to preserve; and
knowing where the shadows will fall to black without detail.
Of course various emulsions have different dynamic ranges.

Lluis and Tarek,
With digital I think in similar terms to color film.
What is the dynamic range of the sensor?
in order to place the highlights where I want them and know where the
shadows will fall.
Further: knowing I have some limited possibilities to extend both ends in
post processing.

For example:
Expose an evenly lit turkish towel (great texture) as metered (zone V).
Increase the exposure in one stop increments to determine when the highlight
detail disappears.
Decrease the exposure in one stop increments to determine when the shadow
detail disappears.
Through testing I have determined that
the DMR has approximately 9.5 stops from deep shadow detail to bright
highlight detail; below that is solid black; above that is solid white.
This is about 1 1/2 stops more dynamic range than the M8; which has about 8
stops from deep shadow detail to bright highlight detail.
And the 5D has about 7 1/2 stops from deep shadow detail to bright highlight
detail.
I say "approximately" and "about" because different levels and types of
lighting; ISO settings; and yes lenses will have effects on these numbers.

If you want to get really crazy
you can bring these test shots into photoshop and read the values (just like
we used to do with a densitometer).
It's an interesting exercise because you'll find greater separation between
some zones than others; a little freaky actually.
(I no longer get that crazy)

Lluis,
I don't know if anyone else is writing about or discussing digital work flow
in terms of the Zone System.
This is simply my own way of understanding the equipment I'm working with;
and my way of thinking about the more critical work that I do.
Just a natural shift from what I grew up with to what I'm doing now.

Others use the histogram to accomplish the same thing.
I find histograms hard to interpret when the subject has a whole lot of
black or a whole lot of white in the frame.
Though I can always rely on my spot meter to tell me what is actually being
recorded and where things will fall.

YMMV

Hope this helps

Regards,
George Lottermoser
george en imagist.com
http://www.imagist.com
http://www.imagist.com/blog
http://www.linkedin.com/in/imagist






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