“…But 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.

“Why 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.

“Can’t 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 discrepancies.

“My 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.

Materials:
- 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

Tips:
- 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 and learn
- 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 me.

Test 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 determine.

The 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).

What 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.

I 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.

2. 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.

3. 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

For example:
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

4. 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.

5. 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.

6. 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.

Which 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

Now 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 to work.

Zone VIII is the first value darker than pure white on the paper.

1. 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 EI.

2. Meter the board and open up 3 stops. Take 3 or 4 exposures exactly like this one.

3. 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.

The 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 be 1.15-1.25.

The 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.

Old 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 time.

4. 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).

After 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 application.

Safelight Fog Test

Safelight 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 safelight fogging.

Place 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.

Do 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.

5 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 it.