Focus stacking – the ultimate solution
■ There are optical limits to depth of field. One is that at very small apertures, such as f/29, the improvement in depth of field is offset by ‘diffraction’, which produces a softness in detail. Another is the high magnification needed in macro photography, which means that even at a very narrow aperture like f/22, depth of field is measured in millimetres when shooting close-ups. One solution that gives the impression of deep focus is focus stacking, which involves taking a sequence of identically framed shots, and changing the focus from one to the next. Specialist software, such as Helicon Focus used here, can combine the sharpest areas from each frame into a single image, adjusting for the slight changes in scale as it does so.