Instructions for the Tone³ |
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The Tone³ (pronounced "Tone Cube") was designed as a testing tool
and a learning tool. Its primary use has been to test new film and developer
combinations. It has also been used as an instructional tool to help in
understanding exposure, light ratios, and contrast. The Tone³ consists
of three tones - black, white, and gray - which are configured so that
each tone is next to itself as well as the other two tones. In other words,
the cube is made up of three pairs of tones. It's the relationship of
these tones that makes the Tone³ so useful. |
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Since most meters read an average of the tones in a scene and most scenes
contain many tonal levels, this standardization can work well for average
photos. When attempting to read a single tone, metering becomes more difficult.
Your camera meter thinks everything is 18% gray. If you were to photograph
a white board at the meter reading, it would print as gray in the final
photograph. |
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Evaluating these areas will mean different things to a portrait photographer than to a landscape photographer. You must decide what is important to your own work. For the example above at f/8 at 1/250, a close-up meter reading of a highlight might be at f/22 at 1/250 (we'll keep the shutter speed constant to simplify things). In the same scene, close-up metering of the darkest shadow might indicate f/4 at 1/250. This should produce a full-toned image with the above exposure. In practice, black-and-white film should retain detail in areas two stops darker than the camera exposure and three stops lighter. This does depend, however, on using the proper film speed, film exposure, and film developing.
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This is simplified by the construction of the Tone³. Because of its configuration, the cube can be placed in such a way as to find the most extreme tonal range (white side in the sunlight and black in the shade, for example) or just to find a normal range (white and black both in direct sunlight), or even to see and learn about light ratios (white in the sun and shade, gray in the sun and shade, and so forth). |
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Having two of the same tones - here white - facing the camera reveals the light ratio. |
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Exposure range is the difference between the lightest tone and the darkest tone in a scene. Exposure range can change even while the light and light ratio remain the same. In the above case, having the black side facing the light source and the white side in the shade will produce a lower exposure range (perhaps 1:1) than the white side toward the light and the black in the shade (possibly 16:1 or greater). Seeing how the various sides reflect light can be very educational. |
Light ratio can change with a change in light direction. |
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With a black panel facing the light and a white panel in the shade, the contrast will be low because the exposure range is low.. Use of the Tone³ is straightforward. When put in a scene, the Tone³ allows you to take three readings - shadow, midtone, and highlight. On initial use, I would recommend writing down your meter readings and camera settings. This makes it easier to determine what went right and what you need to change the next time you shoot and develop your film. |
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When a white panel faces the light and a black panel is in the shade, the contrast will be high since the exposure range is high. Notice the light ratio has not changed in either shot. |
Light readings should be made with a spotmeter or a reflected meter used very close to the tone. If you are using your camera's meter, do not worry if you can't focus that closely. Fill the frame with the tone, making sure you are not affecting the reading by blocking light, and meter without focusing. Since you are metering for a tone, the focus is not critical. In fact, focusing too close can affect the reading due to lens extension factors which reduce the amount of light reaching the focal plane. |
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The midtone of the Tone³
is an 18% gray and should give you an average reading. Most black-and-white
photographers prefer to use meter readings of shadow areas to determine
exposure (although some portraitists choose to use a midtone). To retain
detail in a shadow area, the camera exposure should be two stops less
than the shadow reading. For example, if you get a meter reading of f/5.6
off the shadow side of the cube, the camera exposure should be f/11 (at
the same shutter speed). This is the equivalent of placing the shadows
in Zone III in the zone system. Note that oftentimes this derived camera exposure (f/11 in our example) might be different from the
reading off of the 18% gray tone (which could easily be f/16 or f/8 in
the above example, depending on conditions). This is why 18% gray cards
give you average results. Understanding that exposure affects the shadows
significantly can help you to retain shadow detail in your black-and-white
photographs. You can also read a highlight panel of the Tone³ to
see where it falls in relation to the camera exposure. To retain detail
in a highlight, it should not be more than three stops brighter than the
camera exposure. If as in the above example, f/11 is the (derived) camera
exposure, the brightest highlight should be no more than f/32. If your tones fall within these limits - shadows two stops
darker and highlights three stops lighter than the camera exposure - shoot
and develop the film normally. After printing, you can determine how good
the negatives are. I suggest using a maximum black test to determine the
best print exposure, though other methods will work. My book, Mastering
Black-and-white Photography, covers this in detail, as do other books.
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