Selective depth
Surround a narrowly focused sharp subject with blur in front and behind to deepen the scene with three overlapping layers
Layering in photography can’t escape the idea of depth; there’s no such thing as a flat-yet-layered picture. Nevertheless, you can choose to make more of the depth by using selective focus in a certain way. Unlike the previous image of the Bulang minority ceremony, where the sharp focus was backstopped on the furthest part of the scene, using selective focus for its maximum depth effect means keeping the narrow band of sharpness somewhere around halfway in, beyond which the focus slides back into a blur.
What these two different types of layering have in common, however, is that in both kinds of image the transparent edge of the foreground blur helps to progress the sense of depth. In the picture above, taken in a Taiwanese temple, the foreground shades to the middle ground, but because of this area of overlapping transparency, we know that it’s in front and we know that it’s separated. Here it hardly matters what the foreground is, only the blur of the pattern and its repetition beyond.
A focus ramp
The key to this kind of focus layering is having a ramp that goes from blurred to sharp and then back to blurred, running across the frame. This ramp can run in any direction, from down to up, corner to corner, or – as in the picture above – from left to right.
The three shots opposite show what happens at three greater depths of field, which are so much less effective that they become totally different images. They contain more information (the patterns turn out to be hundreds of small niches)
but give viewers less sense of being there in three dimensions. Yes, you can keep depth fully focused, so that everything from foreground to background is sharp (Ansel Adams’ near-far style), but this relies on shooting wide-angle and that special involving feeling of a short focal length.
Our main image with selective focus is simpler – a 70-200mm lens at 95mm and wide open at f/2.8 – and works without the viewer having to know anything about the blurred areas, using simply the sensations of blur and sharpness.