Depth of Field

ndeniably, working at the close camera-to-subject distances required in macro photography differs greatly from shooting “normal” scenes, particularly in aperture choice and the resultant depth of field (front-to-back sharpness in an image). This brings me to the first optical law you should learn: The closer you focus on a given subject, the larger the subject and the shallower the depth of field. That’s both good news and bad. It’s great if you want to see something up close, but it’s bad if you want to see it all in crystal-clear sharpness. When you are close up, depth of field is always shallow, so getting everything in focus is challenging and not always possible.

In addition, the distribution of depth of field in close-up photography differs from that in normal photography: In close-up work, the depth of field extends equally in front of and beyond the subject; in other words, half of the area of front-to-back sharpness will be in front of the subject, and one half will be behind it. In regular photography, depth of field is distributed one-third in front of the subject and two-thirds beyond it. This needs to be taken into account when deciding where to focus.