Shallow depth of field by means of a wide aperture emphasizes a landscape in compelling ways, stepping outside the everything-sharp genre, while encouraging spontaneous creativity and freedom of movement without a bulky tripod.
In daytime lighting, our usual inclination with landscape photos is to eagerly stop down for increased depth of field, to equalize sharpness everywhere. But equalizing sharpness near-to-far places the same sharpness emphasis on everything in the composition, which does not by itself make a stronger image. Eliminating the powerful tools of sharpness and blur by always stopping down makes one’s imaging toolkit less flexible, promoting reduced creativity.
With a lens set to a wide aperture such as f/1.4, the combination of vignetting and minimal depth of field focuses the viewer’s attention sharply, even if the over- all image is less sharp. Thus, less sharpness overall might mean that more is communicated.Observe that a telephoto lens is often used for its benefits of isolating a subject; a wide aperture exerts similar visual power.
From a perceptual standpoint, sharpness is relative. The in-focus eyes seen in a portrait stand in sharp comparison to out-of-focus elements, none of which need to be sharp in a portrait context.
Landscape images with pin-sharp details everywhere are by default about the entire scene, yet many compositions feature a single item in its context (a boulder, a tree, a mountain peak, an animal). The surrounding elements are important, but in most cases are needed only for contextual support. With everything equalized in sharpness, the eye and mind lack guidance other than the spatial arrangement of elements in a 2D plane—why should compositions not also direct the viewer’s attention using sharpness differences, making use of 3D visual cues?
Out of focus elements in the scene can communicate more quickly, and perhaps more subtly, because the mind is free to perceive in an orderly way, focusing attention on one element, with environmental information settling into place, perhaps even unconsciously. Sharpness everywhere impedes intuitive perception of the whole, just as we cannot perceive everything at once in reality; we must focus on something in particular to be fully aware of it. While brilliant landscapes with blue sky, clouds, flowers and everything pin-sharp are “pretty,” I rarely find those scenes very interesting any more; I’ve felt a personal need to seek out new approaches that don’t remind me of the postcard look. Since every lens “draws” with its own style wide-open, creative options emerge that are not possible with a lens set to f/11. To date, my favorite lens for such work is the Leica 50mm f/0.95 Noctilux-M ASPH.
A wonderful benefit of shooting wide open is abandoning the tripod, allowing more creative exploration, a wider variety of shooting angles and a less stressed neck and back.
