My world is in color. It’s beautiful. Black and white shows a different world, one I only see on paper. It removes the distractions and clashes that color can introduce. Suddenly shadows, light, shapes, lines and textures leap out in a harmonious way. The image can feel more cohesive.
I try to capture (or create) an atmosphere, not a scene. Broadly I think the atmosphere can be changed by adopting either a bright high key and washing away shadows or a darker low key, possibly with its related high-contrast noir style. I tend towards the low key/noir end of the spectrum and for my taste I think that atmospheric style is suited to black and white.
Black & White Photography Tips
1. As with traditional photography you can choose to capture black and white directly or you can capture color and convert to black and white in post processing. To start, try comparing the results from both methods. Spend some time capturing in black and white. The native camera app has a couple of options (including Noir) and there are a range of specialist black and white camera replacement apps.
2. There is one technical shortcoming of iPhoneography that for me can be beneficial in black and white – noise. It means that in low light conditions or on the rare occasion that I want a heavy crop, image quality in terms of noise becomes a problem. What we define as noise in color photography with a bit of editing can be very pleasing grain in black and white photography. I very often actually add grain to black and white images to enhance the atmosphere.
3. When it comes to converting color images to black and white, don’t just be content with “convert to black and white” or “de-saturate”. Many apps have a wide range of conversion options and presets. Experiment with them. Look especially at two areas – (i) adjusting brightness, contrast and noise levels (the results can be very different when comparing black and white and color), and (ii) use the color filters when converting. Notice for example that a green filter will tend to work with skin tones whilst a red filter will add drama and contrast and can result in some spectacular landscapes.
source: iPhone Photography School