How do you produce a great black and white photo? You must learn to see the value in light and pick strong subject matter.
There are good reasons for teaching photography students with a manual camera and b/w film. Trial and error with b/w film helps students identify subjects, control contrast, use shadow to create mood and see the value of light.
In b/w photography tonality, subject choice and composition are vital to a good photo.
In color photography, red and green are obviously different, but in b/w they are not so different. They are both very similar shades of gray. The best way to understand this is to become color blind.
Look at the image above. It is an accurate example of color blindness and also an accurate example of gray tones in b/w photos. The grays in that image are very similar even though the colors are stark opposites. If not for the texture of the circles it would be a muddy mess. The exposure is correct though.
How do we deal with this problem of similar tonality?
We can choose subjects which stand out in comparison to the other gray tones in the image.
We can use shadows to create depth and separate similar tones.
We can adjust contrast in the entire image when printing or processing.
We can filter the image. By limiting or enhancing the amounts of a certain color passing through the lens, we can change it's tone. In this way we can create a desired contrast. Let's take a look at some examples:
What do we see in the pics above? Note how close red and green are in tonality in the neutral image. By using filters we can separate them. Now look at the red filter image. The red and green have reacted in opposite ways. Why does this occur? Simple, colors have opposites. Red is an opposite of green. Yellow is an opposite of blue. By changing the brightness of one, we also change the brightness of it's opposite. If we brighten red with a red filter, we also darken green at the same time. If we brighten yellow, we darken blue. Brightening green darkens red. Brightening blue darkens yellow. Notice also that more than one opposite color is affected. Use the color wheel as a reference when using filters in b/w photography.
We can use color selection to control tonality. The hue or darkness of a color affects how it is exposed on film. Red looks darker than yellow so in the neutral image above, the red tag is darker than the yellow cap. Green and red are similar in their depth of color so they appear as the same brightness in the b/w pic. This leads us to reflectance.
We can consider an object's reflectance and it's affect on exposure. Our eyes are not fooled like a light meter by white and black. Objects of high reflectance are simply brighter than objects of low reflectance. If you have a scene with a black horse and a white house you know the house will be brighter. You can assign values from 0 to 10 to the objects in your scene in order to judge their brightness in comparison to each other. A black horse may be a 1 while a white car may be a 9. A green lawn may be a 5. By assigning reflectance levels to your scene you can more effectively judge exposure and contrast. Use this guide to help determine tonality in your image. Each number is half as bright as the next number.
0 1 2 3 4 5 6 7 8 9 10
0 Pure black
1 Near black, with slight tonality but no texture
2 Textured black; the darkest part of the image in which slight detail is recorded
3 Average dark materials and low values showing adequate texture
4 Average dark foliage, dark stone, or landscape shadows
5 Middle gray: clear north sky; dark skin, average weathered wood
6 Average Caucasian skin; light stone; shadows on snow in sunlit landscapes
7 Very light skin; shadows in snow with acute side lighting
8 Lightest tone with texture: textured snow
9 Slight tone without texture; glaring snow
10 Pure white: light sources and specular reflections
Choosing strong subjects for b/w photography is very important. You must clearly define your subject and make it stand out in the scene.
Convey emotion, personal struggle or character in your image. The most memorable b/w images record people at their best, worst and in the course of their daily grind. Tell a story with your photo.
Make the subject easy to see whether it's a musician on stage or a tree alone in a meadow.
Choose bold subjects with strong patterns and textures.
Composition is very important. There is no color to draw the eye through the photo.