Black and white photography focuses more on light intensity and contrast than color photography. When color is stripped away details of objects become more prominent to the eye and different parts of a scene can become more important than in a color image. Almost every image can work as a black and white photograph. The main exception to this are compositions that rely on color to tell the story. For example, an image of a purple flower amidst a group of yellow flowers, will not have the same impact in black and white as in color.
So what makes a good black and white photograph?
Like so much of photography, this is often a matter of personal taste. However, there are a few items that can really help the impact of a black and white photograph.
- Wide Range of Tones
Having a wide range of shades of black/grey and white can help add a strong sense of depth to your black and white images. Images that are literally only black and white (or close to it) create an almost illustration effect, like an ink pen drawing without shading. - Contrast
Because black and white depends on shading to help show boundaries between items, good contrast between objects (via color or lighting) is a great help in creating a strong black and white image. While we usually try to find colors that do not clash with one another in color photography, clashing colors can help create contrast when captured as black and white. - Good Lighting
Good lighting is an almost universal need in photography. With black and white photography it can be even more important as a slight shadow becomes a charcoal grey over whatever is in it. With black and white photography it can be much more difficult to recover details in shadow after capture than with color film.

