> ...
> As I may be teaching some alternative process classes, I will most likely
> teach my method, but would love to know (and explain / warn my students) if
> my method isn t standard. I may just have to buy (and read) Phil Davis s
> Beyond the Zone System book, but it looks like way too much math and
> theory to be fun !
>
> tomf2468@usa.pipeline.com (Tom Ferguson)
>
The purpose of the Phil Davis Beyond the Zone System (BTZS) approach is for
you to gain a better understanding of the materials that you are working
with. It does have more graphs and math than other methods, but it need
not be tedious or very difficult to use.
I usually study a number of approaches to something, choose the method
that I think will work best for me and my way of thinking and then jump
in and try it. This is what I did with the BTZS approach to film and
paper testing. I should state that I have looked at other methods and
understand how they work, but I decided that the BTZS approach was the
best for my needs. As usual, we all should use what we feel comfortable
with and what works best for us.
The Phil Davis BTZS book shows you how to analyze film and paper curves
generated by printing a step tablet onto either film or paper. The step
tablet is usually contact printed onto film and either contact printed or
printed by projection onto paper. You should use the paper method that
is similar to how you print negatives.
When working with film, you need to expose 5 negatives using the same
exposure. You then develop them from 1/2 to 2 times the manufacturer's
recommended development time.
You then read the density of the portion of each negative that
corresponds to the each step of the step tablet with a transmission
densitomer and record them. For paper, you read the reflected densities
using a densitometer capable of read them.
At this point, you can follow the instructions in the BTZS book and graph
the paper and film curves. Phil Davis explains how to analyze each curve
and the various methods for determining things like film speed and
everything else you need to know about the paper or film.
To me, some of the analysis was a little hard to follow at first. Before I
did any actual testing, I purchased a BTZS Workshop tape from Darkroom
Innovations (contact info later) that made everything perfectly clear to
me. For example, watching Phil Davis show a student how to move that ISO
film speed triangle to position it properly, made its use obvious to me.
The BTZS Workshop video shows how to analyze the film and paper curves by
hand, but suggests using a computer program that Phil Davis developed to
make the analysis very fast and easy. The program is call Plotter and
it allows you to enter the densitometer data for film and paper curves
and then it does all of the plotting and analysis for you. You have
control over how it does most of the analyzis and can put in estimates
for variables such as the amount of flare that a lens has.
I also use an exposure calculator developed by Phil Davis and sold
through Darkroom Innovations. It allows me to use the Phil Davis version
of the Zone System or his Incident System, which I usually use, plug in
my meter readings and get the exposure determined for me. It also
adjusts for filter factors, bellows factors and reciprocity corrections.
This may all sound rather technical, but it is actually very easy to use
and I find that it allows me to concentrate on taking a photo. I simply
decide how I want a scene to look, take a couple of meter readings, punch
them into the calculator and it gives me the exposure and the average
gradient that the negative should be developed to. I make the exposure
and write the average gradient number down.
Using the exposure calculator, the only analysis that I really need from
the Plotter program is a graph that shows development time versus
negative average gradient. I usually generate this graph using a target
density range of 1.1 with is appropriate for my negatives enlarged with a
color (diffusion) head. You also need to input this density range into
the exposure calculator as the exposure scale for the negative.
To develop the film, I simply lookup at the graph of development time
versus average gradient and pick the time that corresponds with the
average gradient calculated for a particular negative. This produces a
negative that should be printable.
To conclude, I want to say that the Phil Davis BTZS approach has allowed
me to understand how my materials interact, let me concentrate on my
artistic interpretation of the scene that I'm photographing and produced
good printable negatives for me. I can highly recommend the BTZS Workshop
video that helped me and the Plotter program that makes the analysis of
the data so much faster. For people that do extensive photography in the
field, as I do, I can also recommend the exposure computer.
This technology has allowed me to concentrate on the artistic side of
photography. It has greatly simplified the technical side of taking a
photo, allowed me to very quickly analyze a new material, and given me
the confidence that I can get the results that I'm looking for
and that they are reproducible. When I had a question about the Incident
System, I sent E-mail to Phil Davis on Compuserve and found that he was
very helpful.
Darkroom Innovations, which I'm not connected with, can be reached at
(602) 488-5117 (Monday thru Friday from 9 AM to 5 PM Arizona Time
http:/204.96.14.109/darkroom/
fnewman@syspac.com (Fred Newman, owner)
note: Fred is a photographer and author and he likes to talk.
He has given me lots of good advice.
I'm sorry that this message has gotten so long. However, I do think that
these tools and techniques can be useful for photographers using
alternative processes. I hope that I've indicated how easy it can be to use
them.
Bill Patterson (wpatterson@asap.bus.wisc.edu)