zone system question

in phil davis' book, "beyond the zone system", he states that the zone system should be used with zone pairs 4 zones apart. for example, zone III and zone VII, zone II and zone VI, etc. is this valid and does anyone agree, disagree, or have a comment regarding the validity of this recommendation. thanks.

I'd been hearing about this book for ages in this forum, and a couple

of weeks ago I finally got my hands on a copy.<br>All I can say is -

what's all the fuss about?<br>The illustrations are uninspiring and of

low quality, the information's shallow and adds little to AA's

original concept, and the advice about incident light measurement

shows a fundamental misunderstanding of it. Have I missed something?

Or is there another book of the same name that's far superior?

Pete,

 

<p>

 

I have to agree that BTZS seems to elevate arcane alchemy to

the staus of micro-surgery. Surplus to requirements for all but

the boffins.

 

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The one notion that I did find plausible, however, was the

incident meter discussion. Not for me, I'm a 1 degree spot

addict, but I ran a buddy that can't afford a spot-meter through the

technique and he's getting more consistent and better exposed

negs than ever before. Not necessarily perfect, just better.

 

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Walter Glover

I agree that the book is aracane and difficult to read in many areas.

I think most of the first half of it could be eliminated without any

loss. However, I know Phil Davis reasonably well and I'd be very

surprised if he has a "fundamental misunderstanding" about anything

related to photography. Of course I've been surprised before, so it

wouldn't be the first time. With respect to the question concerning

the validity of the "recommendation," it's been quite a while since

I read the book but I don't offhand recall a recommendation that zone

pairs always be placed four zones apart. As a general rule, there are

considered to be five zones in which detail will be seen in a print

made from a normally developed negative, Zones III through VII, and

these zones are four apart. Are you sure he wasn't just saying

somethinglike this, as opposed to "recommending" a placement like

this? The whole idea of the zone system is to permit aesthetic

judgements about how a scene should look in the print and then to

permit you to expose and develop your film to achieve that look, so

it would be a little surprising to find someone suggesting that zones

should always be four apart as any kind of inflexible rule.

Actually I think you are confusing SBR (Subject Brightness Range) and

development reccomendations. For example a normal SBR that requires a

N develpment has 5 zones. so you can hace ZIII to ZVII if you wish to

render the image darker or lighter you can move the zone placement.

Now you dont have to have these type of zone separation it can be

different ones, is just that what Davis calls a "normal" SBR.

 

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IN the end I found this book and the techniques way more complicated

than they should be. THe zone system is only a way comparing and

controling exposure and developing and as AA and others explained it

is very simple.

The best book I have ever read about the Zone system, is the Zone VI

Workshop by Fred Picker, not complicated at all. Pat

Howard, The bigger the difference between the scene brightness or

the "zones" you plan to place them on will result in lowering the

possibility of picking the wrong development time. Of course, some

subjects are very low contrast and you will be forced to use a value

less than 4 zones apart. If you are a precision person, there is

another alternative to the Zone System. I wrote a series of articles

for Photo Techniques magazine that describes the theory and practice.

Testing is tedious but using it in the field is as easy as the Zone

System and far more precise. Study everything you can, trust your bs

meter to keep you on the straight and narrow, and go have fun making

images.

Mr. Schwartz:

 

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Davis recommends that you stay with a a four zone spread

because using a larger or smaller zone spread will build into

your exposure/development calculations an error in the

estimation of the total subject brightness range, which, in turn,

will lead to an error in the specified development time.

Remember that you are trying to make a negative whose density

range will fit perfectly on your chosen type and grade of paper.

To make such a negative you must find the right development

time. You do that by, in effect, determining the total scene

subject brightness range by measuring a portion of it -- the low

zone-high zone spread -- and consulting the graph you have

made from your test data of subject brightness range vs.

development time. In BTZS, 4th ed., at pages 125 to 126, Davis

explains how choosing zone pairs with a spread greater or less

than 4 can lead to an error in the estimation of the total subject

brightness range. In his example two different scenes are

measured, one using a a four zone spread and one using a six

zone spread. each calculation leads to a development

recommendation of N-1. Yet the subject brightness ranges of

the two scenes differs by about 2/3rds of a stop. As Davis says,

"obviously development that's correct for an 8 & 3/4 stop subject

cannot also be optimum for an 8 & 1/6 stop subject . . . ." (Davis

goes on to say, "you may or may not consider this to be a

significant error because both negatives will undoubtedly be

printable.")

 

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The recommendation, therfore, is certainly valid. I think perhaps

the question you are really asking is whether the error introduced

by picking a zone spread other than four is really worth worrying

about. My answer is that if your scene permits you to use a four

zone spread why not do so and avoid one possible source of

error? On the other hand, not every scene lends itself to 4

zone-spread metering. If I understand what Davis is saying, you

should not hesitate to meter and shoot with an alternate zone

spread. The error you introduce may mean that your negative

will not fit your paper perfectly, but it should certainly be

printable.

 

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Remember that Davis's variant of the Zone system, like the

original, is meant to aid your photography, not hinder it.

 

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Mr. . . . Andrews, I think it was, says about Davis's book that, "the

information's shallow and adds little to AA's original concept . . . "

I'm not sure what he means by saying that the information is

"shallow." If by "shallow" he means "straightforward" that would

seem to me to be a good thing. I want the artistry in my

photographs to be "deep" (if at all possible); I am perfectlly happy

for the technical stuff to be as shallow as possible. As for the

claim that the book "adds little to AA's original concept," I'm sure

that, conceptually, this is absolutely true, and that Davis would

agree. What BTZS does is to provide a way to minimize certain

errors that creep into our exposure/development calculations,

like the one mentioned above, and to generate quickly and

relatively painlessly, the data necessary to make reliably

accurate exposure-development calculations under a wide

range of subject brightness conditions. For example, BTZS

makes it easy to select the correct film speed for the scene's

subject brightness range (remember that as the subject

brightness range increases, so that minus development is

indicated, exposure must be added to account for the loss of film

speed brought about by the curtailed development time). How is

this information generated using the more traditional zone

system approach? The methods recommended by White,

Lorenz, and Zakia in their New Zone System Manual are vastly

more complicated and time consuming than Davis's aproach.

Of course there are simpler approaches to the film speed

problem; a number of my friends seem to use trial and error with

a high degree of success. As I have said in earlier postings

defending Davis's book, wonderful, technically accomplished

photographs are made all the time using the traditional zone

system approach, and even the no-system approach. (To take

just one example, Jock Sturges makes beautiful large format

B&W images, and is said to loathe the very idea of the zone

system). But for those for whom a somewhat technical

approach is not too daunting, Davis's variant of the zone system

works very well.

 

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David Mark

 

The fundamental misunderstanding of incident light metering is

illustrated by the recommendation to take a reading next to the

brightest part of the subject (where possible) and next to the

shaded part of the subject, then equating these two readings to a

subject 'luminance' range.<br>This actually tells you almost nothing

about the subject brightness range, and is a complete misuse of an

incident meter, which already takes the 7 stop range of a normally

developed film into account. The method is more applicable to a simple

wide-angle reflected meter, which seems to get almost no mention in

the book at all.<p>My other objection to the book is that it wades

straight into 'sensitometry made obtuse' without mentioning the

fundamental reason for using it. The underlying principle of the Zone

system is, or should be, pre-visualisation. I don't think I saw a word

about pre-visualisation in the whole book.<p>When AA first thought up

the zone system, film speeds weren't very standardised, and

manufacturers didn't issue comprehensive sensitometry data about their

products. He was forced to spend a lot of time characterising the

materials he used.<br>I'm not entirely convinced that such an approach

is even valid today; let alone recommending to people that they waste

time making a poor densitometer from a perfectly good spotmeter, and

THEN recommending that they use an incident lightmeter to take subject

brightness range readings.<br>It's like a DIY book recommending that

you use a screwdriver as a chisel, and then knock your screws in with

a hammer!

People are always trying to make any system better but few succeed. If

you understand what the zone system of film exposure and development

is telling you about the response of film to development then you need

look no further. But people for some reason need to make something

that is incredibly simple into something that is hard to understand.

And that is what Fred Davis did for us. Why do we continue to fight

such a stupid battle when none exists? AA worked out a system that

works like a charm. Davis, and many others, just made it more

complicated than it needs to be. Read AA's discertation on

the zone system, do the calibrations, and enjoy making

images. Nothing simpler than that. Show me where there are errors in

it and I'll follow it.