As mentioned in the section on light sensitivity the manufacturer's recommended speed rating
should be used as a guide. To assess the effective speed of a particular
film with your own particular equipment it is necessary to make a
test for yourself.
If you normally work in a studio then make this test with the lights
you normally use. If you work outside it is best to make the test
in lighting conditions which are relatively stable.
Find a high contrast scene by measuring, with your exposure
meter, the difference between particular light and dark areas
so there is a difference of about 8 stops or zones.
Start by using the manufacture's recommended speed setting (ISO).
Measure the exposure of the dark area where you want to see just
a hint of texture in the shadows or the first suggestion of texture
in the shadow detail (zone 2). Set your camera to reduce this
exposure reading by 3 stops (or 3 zones). For example, if this
shadow reading gave an exposure of f2.8 then close the lens (by
-3) to f8.
Expose the film to this exposure setting. Then make a series
of six other exposures by altering the speed settings on your
light meter by one third. For example, if the manufacture's recommended
speed setting is ISO 100, then first set the exposure meter at
ISO 100. Then alter the settings to slower speeds of ISO: 80,
64 and 50 and then make three more exposures to faster speeds
of ISO: 125, 160 and 200.
Make careful notes of the 7 exposures and then process the film
in your chosen developer and remember to keep the temperature
and agitation methods consistent. See processing
When the negatives are dry place them on a light box and carefully
assess which negative shows the first hint of detail in the shadow
area (the shadow area you choose to calculate the exposures).
The speed setting for this particular film (in association with
the development and camera equipment) is measured from the negative
you choose. For example, choose the negative with the zone 2 shadow
detail and if this particular negative was exposed at a film speed
of ISO 80 - then ISO 80 would be the speed of this particular
film in combination with the equipment and chemistry you have
The method for exposing colour or B&W slides correctly is different
from exposing negative film and finding the exact exposure is more
critical with transparency. Unlike making exposure readings for the
negative where it is important to base the exposure from the shadow
detail, with transparency the exposure has to be calculated from the
high-light or white detail. An incident light exposure reading is
recommended for this. It is ideal to use a hand held exposure meter
which has a diffuser attachment, this measures the incident light
that falls on your subject to achieve a high-light reading. The diffuser
is normally a small translucent white dome which can be attached to
a hand-held meter.
The exposure method is then quite simple: point the incident exposure
meter diffuser towards the camera from (the light falling on) your
subject and read the settings.
If you only have a reflected light exposure meter or one built in
your camera then I would suggest you take a reading of a white area
where you want to see some detail or texture and set this reading
on a zone 8 (or open the lens by 3 stops from the white textured meter
reading). For example if the white area exposure reading indicates
an aperture of f22 then open the lens (by +3) to f8.
This method can be very useful if the light levels are too low for
your exposure meter to record an average reading (mid grey or zone
5) but where you can just make a reading from a white object.
In the landscape the quality of light is very variable and individuals
need to assess the quality of light to suit their own requirements
to create mood and atmosphere or to make dramatic or subtle images.
The climate has a dramatic effect on the quality of light in the
landscape. It is worth noting that a very high contrast lighting situation
can be experienced when the atmosphere is clear and the sun is at
it's highest point in the sky. What is significant about this, in
terms of exposure, is that there will be relatively less shadow detail
with clear blue skies in sunshine than with cloudy skies in sunshine.
The shadow detail may be brighter with cloudy skies than with clear
skies and in some cases the exposure will need to be longer for a
sunny day than a cloudy day ! The higher contrast of stark sunlight
can then be controlled by (reducing) development or, as a last resort,
changing paper grades when making a print.
With experience, I have found that I do not normally need to use an
exposure meter with an average Northern Europe landscape between April
and October, except for the hours around sunrise and sunset or if
When using negative film rated at ISO 80, with a yellow filter
(x2 or 1 stop) over the lens: in sunlight I set my camera to 1/30th
second at f11 and is equal to the same exposure as 1/125th at f5.6.
(Without the yellow filter I use 1/60th sec. at f11). Using shorter
expo sure settings will often results in a loss of shadow detail.
If the weather is cloudy and bright, with the yellow filter,
I set the exposure to 1/30th at f8. I would recommend that these exposure
times are used in conjunction with my processing
The zone system is an ideal method for processing individual sheet
negatives where exposures take account of shadow detail and the contrast
(measured by the white detail required) is controlled by development
times. These notes are of particular use to roll film users and should
be read in conjunction with the chapter on exposure.
Film manufacturer's recommended developing times tend to give a
negative of high contrast for general landscape scenes. I use development
times much less than the recommended times.
If you use a particular combination of negative film and controlled
development and your results consistently produce prints of an unsatisfactory
contrast when using exactly the same camera and enlarger on a normal
grade of paper - then alter the development times for your negatives
to achieve your normal development time. If you find that you have
low contrast prints on your normal paper and you have shadow detail
in the negative then increase the development times when processing
your film - start by increasing the development times, initially
by 10%. If, on the other hand, the contrast is too high then decrease
the development times, initially by 10%.
Increase or decrease the development until you can fine tune the
development times which gives the best result for you. Remember to
keep the temperature and agitation methods consistent. Be careful
not to use development times less than half of the manufacture's recommendation
or less than 4 minutes - as even development and exact contrast control
will become difficult.
This simplified zone system may seem complicated at first but practice
makes it much clearer. Understanding the principles of the zone system
will help you enormously when faced with varying subjects and difficult
lighting situations - as it will help you to pre-visualise the tone
and contrast of the finished print.
There is a wide choice of B&W negative developers but there are
two main types, characterised by the fine-grain developer and
the high-acutance developer.
The fine grain developer creates a "softer" grain, where
the grain structure is not as well defined and gives the appearance
of a finer grain. Typical general fine grain developers are Ilford's
ID 11 or Kodak's D 76 and HC-110.
The acutance developer gives a sharper grain structure by increasing
the contrast between areas in the image, known as the "edge effect".
The grain size and the overall contrast is more pronounced with these
developers. Agfa's Rodinal is a typical acutance developer.
There is a variety of developers with combinations of these two
characteristics. I use ID 11 and I dilute this developer 1 + 3. The
increased dilution of the developer will increase the film's acutance.
The following processing guide is based on my normal development times.
This produces a negative of the contrast and tone that suits my needs
and takes into account the substantial contrast range found in the
landscape. These times, film and chemistry can be modified later to
suit your own requirements.
As a starting point you may wish to follow my technique by using
Ilford's FP4 120 roll film (which I rate at ISO 80). Use Ilford ID
11 or Kodak D76 developer, dilute 1 part developer to 3 parts of distilled
water. Process for 8 minutes at 21 degrees centigrade. In a day light
tank, agitate the developer by one inversion of the tank every 15
seconds for the first minute and then agitate every 30 seconds for
the following 2 minutes and then once every minute for the remaining
5 minutes. In the first stages of development remember to tap the
bottom of the tank on the work surface after agitation to dislodge
any air bubbles on the film.
For Ilford FP4 - 5x4in. sheet film, develop the film as above but
increase development time to a total of 10 minutes.
Note that ID 11 developer is mixed from powder with water (I would
highly recommend distilled or purified water) and needs to be left
for at least 24 hours before use. The developer will oxidise if stored
for long periods or if the bottles are not completely full. Oxidisation
will increase the activity of the developing agents and processing
times will need to be reduced.
After developing the film use a stop bath and fixative following
the manufacture's recommendations. Ensure that all chemistry is exactly
the same temperature including the wash rinse water. Use a fresh and
non-hardening fixative for the prolonged life of negatives. Every
process after the stop bath will dictate the condition and useful
life of the negatives.
After washing, place the negatives in a rinse aid (wetting agent
or foto-flo) diluted with distilled or purified water for about a
minute, agitating the negatives a few times. Then, with the film still
on the spiral-holder, shake off excess water. Use a negative squeegee
or a soft "shammy" leather to carefully wipe the film and
remove water droplets. I would not recommend using your fingers for
this task. Removing water droplets at this stage is important to avoid
Hang the negatives to dry in a warm and low-dust environment. Use
fan assisted drying cabinets with care as circulating dust may stick
to the moist gelatin film. Always handle negatives with extreme care
- do not touch the surface of the negative with your fingers as moisture
from the skin is often oily and acidic. When dry, place the negatives
in stable acid-free negatives bags and store in a cool, dry and dark
environment free from dust - this will ensure the negatives remain
in good condition for a long time.
Ideally, the negatives achieved by these suggestions will produce
fine grained and detailed prints that have a rich and wide tonal range.
These negatives should be relatively easy to print without the need
for excessive "burning in" or "dodging".
© John Davies 2010