Getting Into the Zone
By: Thomas Harrop
From Vol. 2 No. 5
There are as many approaches to dealing with the challenges of photography as there are photographers. Each month in this column I will share a bit of the way I handle exposure and tone control. After nearly twenty years of as a photographer, teacher and workshop leader I have developed a range of techniques that work for me and my students. Beginning with some basic testing we will proceed through a look at the zone system and other useful exposure control methods and then on to camera handling and approaches to different subject matter.
We encourage readers to send in specific questions or problems they have encountered. We will endeavor to find answers to them and will respond directly to each questioner and include the most interesting and widely applicable solutions in this space.
While I will be staying out of the darkroom as much as possible (I leave that to the esteemed Mr. Anchell) this column must at least present the short version of a couple of important tests. I encourage those interested to read some of the books that are currently available, such as The Practical Zone System by Chris Johnson. Another good resource is the Cicada internet site with a tutorial on the zone system. You can find them at http://photography.cicada.com.
Anyone working in black-and-white should test to get an idea of what sort of range their materials can produce. This is necessary in part because of the nature of all imaging processes. An outdoor scene may have a brightness range of 10,000 to 1. In other words, a brightly lit, high key subject outdoors may be 10,000 times brighter than a shadow in the same scene. While our eyes easily adjust to this range, photographic materials are able to capture a much more limited range. By testing our materials we can begin to see how we can tailor our previsualization to include an understanding of the limits or photographic reproduction.
The tests we will examine are scaled down versions of much more complicated tests that are used by film companies and scientists to determine the speed and characteristics of photographic materials. All of the testing we will do can be done with any special equipment. You will need a camera, some film, access to a darkroom and a good pair of eyes. Thats about it.
The first tests we will examine are: minimum time for maximum black and a personal film speed test. The first test will give you a time to use for all your contact printing, film speed testing and even enlarging with the addition a technique for using your light meter in the darkroom.
Minimum Time for Maximum Black
This test will create a reference for the darkest black your chosen photographic paper will produce, and to determine the shortest amount of time your enlarger set up will require to produce it. This is necessary because it provides you with a standard reference time so that when you start looking at film tests you will be able to judge whether your exposure times are correct and what film speed you should be using.
In order to allow for the base density of the negative you will be printing you need to produce an unexposed but processed negative to do the test. If you are using 4x5 film this is easy. Simply process one sheet of unexposed film and use it for the test. Roll film is about as easy. Next time you expose a roll of film wind the last couple of frames through and clip them off when you process the film.
Whichever film format you use, the next step is to set up the enlarger for the size print you make most commonly. Once your enlarger is set up for the standard print size (it doesnt matter what size) follow these steps:
1) Insert the cleared negative into the negative carrier so that the cleared film covers half the frame. This means half the frame is film and the other half is empty.
2) Set your enlarging lens two stops down from wide open. If your lens is f/5.6 wide open you should stop down to f/11. With most lenses this is the sharpest aperture.
3) Place a piece of paper in an easel or loose on the baseboard and expose for the following series of exposures.
One second with the paper uncovered.
Cover 1/5 of the paper and do another one second exposure.
Cover another 1/5 of the paper and expose for two seconds.
Next 1/5 of the paper expose for four seconds.
Final exposure for eight seconds.
So the exposure series is: 1 second, 1 second, 2 seconds, 4 seconds and 8 seconds. This will result in a test strip that gives a 5 stop range of exposures in 1 stop increments. The exposures are 1, 2, 4, 8 and 16 seconds. This may seem a bit confusing but it is a great way to start seeing exposure in the darkroom the same way you see it in camera. In other words, you never change your exposure outdoors in two second increments, you change in stops or fractions of stops. Working that way in the darkroom will help keep you vision of exposure consistent.
Once the test is processed and dried, check to see which stripe is completely black all the way across the sheet. This is the minimum time for maximum black. In other words, this is the shortest amount of time you can expose a piece of paper under your enlarger and get the deepest black from your paper with a negative in the carrier.
If you have a hand-held, incident light meter you can extend the usefulness of the test by taking a reading on the baseboard and recording the ISO, aperture and speed obtained. The ISO you choose doesnt matter as long as you set it the same every time. If you record this reading you can set your enlarger for the minimum time for maximum black by simply setting up your enlarger and duplicating the readings you recorded. You can set your enlarger for a 16x20 print (or any other size) then use the aperture of the enlarging lens to recreate the meter reading you recorded from the test, and you will get an exposure that is equivalent to the one obtained for the test.
With the minimum time for maximum black you are ready to make a well defined proof of your film. Set the aperture and exposure time and place the film you want to proof under the enlarger. Since you have established the time it takes to print for the deepest black you can get the proofs made at this time will show the what your camera exposure and film processing have actually created. We will discuss this more in future issues but if you start using this standard now you will find over time that it makes your printing easier because it is standardized. It is one less variable to worry about in the darkroom.
Personal Film Speed Test
There are myriad ways to test film speed. Many require a densitometer and because most photographers dont have access to one, I am offering a simple test that you can do in your back yard. If you are careful with the test you can establish a film speed that works well for your equipment and processing style.
Here is the test procedure:
1) Create a scene to photograph which contains the following items: Something black, something white and a gray card. In addition I usually include a person as a flesh tone reference.
2) Photograph the scene using the following exposure sequence:
Frame 1) Metered at the films rated ISO speed.
Frame 2) Open up two stops from the first exposure.
Frame 3) Open up one stop from the first exposure.
Frame 4) Open up one half stop from the first exposure.
Frame 5) Close down one half stop from frame one.
Frame 6) Close down one stop from frame one.
Process the film as you normally process film then make a proof using the minimum time for maximum black we established in the last test. The resulting contact sheet will show you the actual exposure values created in your film.
To determine your personal film speed simply select the frame that looks best to you and determine where it falls in the exposure series. If frame one looks best you should rate your film at the ISO speed published by the film manufacturer. Film speeds double and half just like apertures so if the frame you judge to be best was exposed at one stop less exposure than the frame one of the test (frame 5) you should rate your film at twice the manufacturers speed. If you are testing film with an ISO of 100, this means you should set your meter at 200. On the other hand, if your best frame was exposed at two stops more open than frame 1, your new personal film speed would be 1/4 the films rated ISO. So, if your film was rated at 100, you would now set your meter at 25.
Keep in mind that these new film speed ratings are not ISO speeds. There is a very precise method used to determine ISO and any speed not calculated according the that standard should be called an exposure index or E.I. Therefore, when noting your new film speed you should get into the habit of calling it E.I. 25 or E.I 200 unless it is the actual rated speed.
You should think of these tests as a starting point. Most of the process of learning black-and-white photography is the elimination of variables. It is very difficult to solve any problem when you have dozens of aspects changing. By standardizing your print time and film speed you can begin to concentrate on other aspects of image making.
In the next issue we will examine some exposure methods, including a simplified introduction to zone system exposure control. Keep in mind that many, if not most, photographers find that their work gets worse for a while once they begin to approach exposure and tone control seriously. The testing process can be challenging but when you have worked through the problems you will find that you can reach a level of nearly total control over your images. Whatever the short term set backs, that is a goal that is worth working toward.