From: donl@glass.esd.sgi.com (donl mathis)
Newsgroups: rec.photo
Subject: Re: Zone Photography Questions....
Date: 29 Sep 92 22:52:15 GMT
Article-I.D.: odin.1992Sep29.225215.17167
Reply-To: donl@glass.esd.sgi.com (donl mathis)
Organization: Silicon Graphics, Inc., Mountain View, CA, USA


In article <nauman.717774681@hq>, nauman@Pt.hq.af.mil (Stratton D
Nauman) writes:
|> If anyone out there in rec.photo land has a good explanation
|> of the Zone system in electronic format that they could email
|> me, I would *tremendously* appreciate it.  The simpler the
|> explanation, the better.

I think we just went though this last month, but of course, we didn't
save it.

The zone system is a collection of tools, and as tools go, they're
more like a lathe than a file.  In other words, you can do a lot with
them, but you have to know what you're doing before you can get it
done.

Most literature, including those counter-productive popular magazines,
and most books, talk about exposure as if there were a single "correct"
exposure for a given subject and film.  This is simply not the case.
The subject consists of a range of brightnesses, and the film will
record a range of brightnesses.  Subjects often (usually) have a range
of brightness that exceed that of the film, so something's going to get
lost.  You can expose for the lower values, but you'll lose more of the
high ones.  You can expose for the higher values, but you'll lose more
of the lower ones.  The choice is yours.

The zone system considers the range of subject brightnesses, and the
range the film can record.  It goes further in that it gives you
control over the film's range, through development control of
contrast.  A good spot meter will help you find out what the various
brightness are in the subject -- you really have to be able to take
each one in isolation.

If you're going to make a photograph, you should have some notion of
what it should look like.  You will have to decide how dark you want
those shadows, and whether some of the darker parts should indeed end
up near black, or whether you really want to be able to see into those
shadows, and look at all the texture in those roots and rocks.  You
will have to decide whether the snow should be rendered as a bright
gray with full detail and texture, or whether you want it so blindingly
bright that you're willing to sacrifice a little detail.

Now, you measure these spots, and start plopping them onto the film's
scale.  The technically correct approach to determining your overall
exposure is to decide what the low exposures are going to be.  Find a
shadow that seems important, decide how dark it should be, and place it
on the scale by twiddling the dial on your spot meter.  If you place it
on zone III, it will have lots of texture.  If you place it on zone II,
it's going to get darker, and lose a bit of detail.  If you place it on
zone I, it's going to be black, or nearly black.  If you place it on
zone IV, it's going to be rather luminous, as shadows go -- a rather
light gray.  Some people place higher values; this is usually not a
wise thing to do until all the rest of the process makes sense to you.

Now that the shadows are pinned down, where do the highlights end up?
If the highlights are six stops above the shadows, according to your
meter reading, then they're going to end up six stops higher on the
film's scale.  So if you put the shadows on zone II, the highlights
will be on zone VIII.  You know from your serious study of the zone
system that zone VIII is going to give you a rather light value with
limited texture and detail.  If that's okay, you can use normal development,
which will give normal contrast. 

If you decide that you want more texture in those particular
highlights, you have two choices.  One is to drop the shadows even
further, so they become zone I where there is much black and no
texture, and the highlights end up six steps higher on zone VII, which
will yield lots of texture.  Since you've already decided where to put
those shadows, you wish you could leave them on zone II, and still
bring those highlights down to zone VII where they will have texture.
No problem!  Just use N-1 development later on, and the range of the
film will be altered to fit your needs.  Now, through this change in
development, six stops of subject range effectively get mapped onto
five stops of negative range. 

The same holds for a subject that needs increased contrast -- you have
a highlight on zone VI that should be on VII, so you use N+1 development.
Similarly for more extreme cases that require N-2 and N+2.  What you've
effectively done is increase or decrease the length of the film's
range by a couple of stops.

And all of this is just so easy you don't even have to think about
it.  There is nothing earth-shaking about choosing N+1 development;
you do it all the time.  And you know when you get to the darkroom
that those negatives are going to require an increased development,
and since you've done your film development testing beforehand, you
know what development times you should use.

The result is a negative that has an appropriate density in the shadow
regions, and an appropriate density for the highlight regions
(according to the length of film scale you chose).  It provides an
appropriate range of densities for you to make a really good print
from.  So you scurry over to the enlarger, and invest the necessary
time and effort to make a good print, throwing out the first 23 of
them once you've learned all you can from them about your mistakes.

|> BTW, I checked out Adams book, the Negative, and 90 percent
|> of it went *way* over my head!  So, something simpler would
|> be appreciated.

This is more of a personal thing, but I'm curious about your reaction.
When I think about the zone system, and what is in The Negative, none
of it seems very complicated, and it seems to me like anyone with
normal or higher intelligence could easily deal with it.  I'm taking it
as a given that you're a smart person, so something else is going on,
here.  I have to guess, though: perhaps it's a matter of new vocabulary
coming at you all at once, or it seems like an endless stream of new
concepts.  Adams tended to write in a rather concise manner; he wasn't
cruel, but he didn't coddle the reader, either.  In my opinion,
everything that should be in The Negative is in there, and there isn't
anything in it that should not be.

I read those books about five times before I thought I was comfortable.

Can you give us some examples of things that you thought were over
your head?

If you're serious about proper zone system work, The Negative is, in my
opinion, really the only place to learn it.  If you pick up almost any
other book on the zone system, you're going to get another
photographer's interpretation of what the zone system should have been,
but I haven't seen any other such interpretations that can be fully
trusted.  I think you should make sure you understand The Negative, and
then if you so choose, go off elsewhere and look at some of the
variations.  The point is that you ought to be able to identify the
errors these other authors make before you subject yourself to their
methods.

|> Background: I only work in B&W, and am extremely serious about it
|> The problem is, I take very good pictures, but not *superb* or
|> excellent pictures, which is where Id like to be.  Ive narrowed
|> my problem down, and from what I read, a serious study of the Zone
|> system would fix it, along with moving to large format.  Specifically..

Okay, now we're getting somewhere.  You sound terribly well motivated,
which makes it even harder for me to understand why you had so much
trouble with The Negative.  Serious study is just that, and it's going
to take a bit of work.  You decide what sort of mental investment you
want to make!  Here's the secret of learning anything: when you come to
something you don't understand, don't proceed.  Do whatever you have to
do to understand it.  Then proceed.  Now, understanding some of those
bits might require a period of sit-down head-scratching contemplation,
especially if the concepts are new to you, and it might require digging
around in some other books or asking somebody some questions.  Feel
free.

|> A. My negatives arent correctly exposed or developed, so that the 
|> entire range of light can be reproduced on paper... i.e. If I print so
|> that the blacks have the correct amount of detail, invariably something
|> *else* (like the sky) is too white.  I believe this could be fixed with
|> proper exposure control, and proper development.  Any Comments?

You're absolutely right.  The answers are in a deeper understanding of
sensitometry.  The Zone System was designed to let you use
sensitometry, and understand what was going on, without getting bogged
down in a lot of logarithms and such.  Still, you're going to be much
better off if you try to understand what's going on in those graphs of
exposure vs. density.  They are not as mysterious as they seem at
first.  They will tell you, precisely, the film speed, the local
contrast at each point on the scale, and the overall contrast.

To get past this obstacle, though, you're going to have to invest
some effort.  You're looking forward to that, right?  :)

|> B.  I'm not happy at all with the detail and sharpness of 35mm,
|> especially in light of the fact that I absolutely *love* to make big
|> prints (8x10s, 11X14s and up!)  Nothing beats 35mm when it comes to
|> catching spur of the moment type stuff, but for gorgeous negs,
|> one must move to a larger format I believe.  So, if anyone out 
|> there has a good introduction to large format that they could email
|> me, Id immensly Appreciate it!

Try "The Camera", by Ansel Adams.  :)  The next step is a real camera,
and a little time out in the world making photographs with it.

And while you're at it, if you want to make good prints, you'll
probably want to read "The Print", too.

- donl mathis at Silicon Graphics Computer Systems, Mountain View, CA
donl@sgi.com