I hate testing” –
If its worth doing, its worth doing right. Testing in general is
not fun. It is however, the most efficient way for you to find the
answers that you may not even know you needed. Testing helps you
avoid problems before they show up on what would have been “the
shot of your life.” Testing is the only way to solve problems
and it will give you confidence in your materials and methods. It
helps you find where the problem lies and what should be done to
fix it. Face it, photography is not painting. Science and scientific
methods are imbedded within it and to truly gain an understanding
of your medium you must learn to accept that you are going to have
to become a bit of a scientist. The more you know about your
materials, the more efficient you will be.
is it important?” – The determination of personal
film speed (EI – exposure index) and personal development
time are of utmost importance for anyone that strives to gain control
over their medium. Completing these tests will allow you, the photographer,
to precisely place the tonal values of the scene with precision
and confidence. No more guessing if it will come out, no more bracketing,
no more unprintable negatives. The limiting factor will be nothing
more than your ability to visualize the scene as you want it to
appear in the final print. This is not, however, a guarantee. Your
results from the tests will only be as good as your consistency.
I just have the Lab do them for me?” – These
tests are personal. They are true only for you. Your values will
not be valid for anyone else, nor will anyone else’s values
work for you. No one else has the exact same meter, shutter, water,
thermometer, or agitation; each contains variability and each builds
on the other. In the end, this cumulative effect can lead to large
thermometer broke, can I use yours?” – In order
to gain value from scientific testing, consistency must be achieved.
Inconsistent methods or materials will lead to errors in the final
results that will not easily be seen as errors and will void the
tests entirely. Any changes made (different film, different developer,
etc) mean that a new test set must be run, no way around it.
- film: buy a lot, buy it at one time, and buy it from a supplier
that sells this film regularly; put the extra in the freezer
- developer: same as above, minus the freezer
- a spot meter
- a new, high quality thermometer: use it to calibrate another thermometer
for back up
- a transmission densitometer: well functioning older models can
be found at very reasonable prices on the internet
- a calibrated transmission stepwedge that covers values from .10
to 1.5 (these can be bought through Stouffer)
- a black mat board, a white mat board, 16x20” each
- have all your shutters checked and adjusted before starting
- start by choosing one film and one developer; avoid specialty
products for now. Pick a good, general use film and developer that
serves most of your needs. Understanding how to use one film/developer
combination will serve you much better than messing around with
more products than the one that you have taken the time to test
- agitation is one of the most difficult things to quantify and
keep consistent, the most important thing is that it be precise,
vigorous and random in nature
- only change one thing at a time
- be consistent
- record everything, keep notebooks for the film developing, for
printing, for testing, for shooting. This will help you to trace
errors and problems, as well as allow you to experiment more efficiently.
The procedures for these tests are adapted from Fred Picker’s
“The Zone System Workshop”, Stroebel’s
“Basic Photographic Materials and Processes”
and Ansel Adams’ “The Negative”.
This article is not intended as an end all guide for these procedures,
if anything seems unclear or you desire more in-depth information,
see the above books or email
for personal film speed (EI) – also known as the
Zone I Test
Manufacturers will rate the film for you. This is the ISO and it
is based on tests as outlined by the International Standards Organization.
Most photographers do nothing more than set their meter to this
value or maybe half a stop less. The ISO means nothing to you except
as a good starting point. This is not necessarily what your meter
should be set to. It should be set to the EI that we are about to
EI primarily determines where the shadow values will fall on the
scale. Using the manufacturer’s, a friend’s or your
teacher’s rating for a film will likely result in the shadows
falling somewhere besides the zone you thought you put them on.
This in turn will lead to shadows that are unprintable (not dense
enough) or shadows that are too far up the curve, which may push
the highlights up onto the shoulder (highlights on the shoulder
do not separate well).
we are trying to accomplish with the test is to see which EI will
give you a Zone I value of .1 above film-base + fog (afb+f). This
is the minimum printable value and will show up on a print as the
first shade distinctly different from the darkest black (max. black).
If you under expose the film, those values that should have been
Zone I may end up at a density less than .1 afb+f, and will be nearly
impossible to print. This test is the beginning in a long chain
of things you can do to precisely, and ideally place your scene
along the film curve. If your Zone I tests are wrong (or not run
at all), your scene placements will be haphazard at best, resulting
in negatives that are difficult or impossible to print, and values
that do not separate as you had anticipated.
have written this test for sheet film users, though you can easily
adapt it to roll film.
1. Find a large area of open shade (like the side
of a large building) that you can expect to have consistent light
levels for an hour or so. Tape the black mat board to the wall,
set up the camera perpendicular to the mat board at a distance that
allows the board to fill the entire frame, but not so close that
you will be shading the board to any extent. Set the lens to infinity,
as we want a nice out of focus, even tone subject. Check that the
board is evenly lit. The reason that we are using a dark board in
open shade is to vaguely mimic the situation in which a meter reading
would be taken for something that would be placed on Zone I.
Set the meter to the manufacturer’s ISO. Meter the
board. You probably know that the meter has just given you an exposure
value that will result in the black board coming out gray. This
is Zone V or middle gray. Close the lens down 4 stops (i.e. close
the aperture or increase the shutter speed. This is now an exposure
for Zone I at the manufacturer’s ISO. Write everything down.
Take additional exposures in 1/2 or 1/3 stops (depending
on your camera) up to 1 full stop on each side of the ISO. These
are Zone I tests at different EIs. Write everything down and make
sure that the negs are clearly marked
Film = Delta 100
Developer = ID-11
Zone I at ISO 100 = 1/4s @ f/11
Zone I at EI 100+1/3 = 1/4s @ f/11+1/3
Zone I at EI 100+2/3 = 1/4s @ f/11+2/3
Zone I at EI 100+1 (200) = 1/4s @ f/16
Zone I at EI 100-1/3 = 1/4s @ f/11-1/3
Zone I at EI 100-2/3 = 1/4s @ f/11-2/3
Zone I at EI 100-1 (50) = 1/4s @ f/8
Now process the film to the manufacturer’s recommended developing
time for this film. Be sure to keep track of which negs are which.
Remember that the thermometer, the type of water (tap, filtered,
distilled), and agitation technique must be the ones that you use
from here on. Any changes will require new tests to be run. We do
not have to yet worry about the fact that the manufacturer’s
development time will probably be wrong for you, development time
has very little effect on the low-mid density (Zone 5 and lower)
areas of the negative.
While the negatives dry, set up your densitometer and get
out your step wedge. Use the step wedge to calibrate the densitometer,
it is best to calibrate it using a value that is close to the values
you anticipate needing to measure. In the case of Zone I tests we
are looking for a value of .1 above the film base + fog levels (which
can be anywhere in the neighborhood of .02 - .16) so use a value
around .18 or so.
Now that your negs are dry, read them on the densitometer. First
read the value of the unexposed edge of the film. Record this. Now
take a reading from the exposed area. Do this for each neg. Average
the film-base + fog numbers, though they should be pretty close.
Now find the neg that has a value .08-.12 above
the average film-base + fog value.
negative is it? The speed at which this negative was shot, is now
your very own Exposure Index. This is the your personal film speed
which you will use to set your meter.
Development Time – Zone VIII Test
that you have established your EI, it is time to see how long the
film needs to be developed to achieve proper placement and separation
of the highlight values. This is called the Zone VIII test. Development
time primarily effects the upper values (zone VI and higher). Longer
development will increase the density of these values, shorter development
will decrease the density. The nice thing about only the upper values
being effected is that it allows something like the zone system
VIII is the first value darker than pure white on the paper.
Time to go back out and shoot again. Set up the camera as before,
but this time use the white board. Set the meter to your new found
Meter the board and open up 3 stops. Take 3 or 4 exposures exactly
like this one.
Process the first negative at the manufacturer’s recommended
time. Recheck the calibration of the densitometer with a value on
the step wedge around 1.4. When the neg is dry, determine the value
above film-base + fog.
value you are looking for is different depending on the type of
enlarger light source you are using. For diffusion
sources the value of the Zone VIII neg should be 1.25-1.35 above
film base + fog, for condenser sources it should
negative processed at the manufacturer’s time will not likely
fit into the proper range because you did not develop it the exact
same way the manufacturer did. If the negative is too dense, then
reduce the developing time on the next neg, if it is under, then
increase developing time.
style emulsions (i.e. Tri-X) do not respond to developing time as
radically as the newer Tubular-grain or T-grain emulsions (i.e.
Ilford’s Delta line, Kodak’s Tmax line). For older emulsions
multiplying the developing time by 1.4 will result in approximately
1 stop increase. For the newer emulsions use 1.1. Adjust the development
time accordingly and keep trying until you get a Zone VIII negative
that falls into the proper range. The development time that results
in a good Zone VIII negative is your personal normal development
For Expansion (+) or Contraction (-), development tests should be
run as above to determine the exact time required to achieve a Zone
VIII negative from a negative that was exposed for Zone VII (expansion
or +1 development) and from a negative exposed for Zone IX (contraction
or -1 development).
running these tests you will have all the information you need to
precisely place any value in a scene as you see fit and adjust the
development accordingly to place the entire scale within the ideal
range. See the article on the Zone System for
Safelight Fog Test
fogging can have a dramatic effect on your ability to produce the
images you desire. Fogging can come from sources other than a safelight,
such as your white shirt, white walls near the enlarger, a darkroom
that is not light tight, or even burning boards that are white on
the bottom. This test will help you to determine the effects of
a sheet of paper in the easel and run a quick test strip with a
negative carrier in the enlarge, but no negative. Stop the lens
all the way down, and run a strip with very short increments starting
at 1 second or less. Process it normally. Find a strip that has
a light, but significant tone (zone VI or VII). Set the timer to
this value. Expose a new sheet and leave it in the easel. Take some
change out of your pocket and place it directly on the paper. Set
a timer for 5 minutes or so. When the time is up, process the paper,
don’t forget to remove the coins. The effect of the fogging
will be seen as circles on the paper. Try closing or adjusting your
safelights until the effect is minimized.
not attempt to run the test without the initial exposure as you
will get a false sense of security because the paper requires at
least a minimum exposure before the tones will change.
minutes may be a bit excessive, but the results will be clearer
and it is better to be working well under the safety margin. In
all situations it is best to minimize the exposure of the paper
to the safelight, develop the paper face down, keep it covered when
preparing to burn or dodge. Also make sure that your easel is painted
either flat black or the safe yellow that many easels come in. Light
from the enlarger can reflect back up through the paper and fog